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Filed Pursuant to Rule 424(b)(5)
Registration No. 333-124795

Prospectus Supplement
(to Prospectus dated December 7, 2005)

$475,000,000

iStar Financial Inc.

GRAPHIC

$250,000,000 5.80% Senior Notes Due 2011

$225,000,000 Senior Floating Rate Notes Due 2009

        This is an offering of $250,000,000 aggregate principal amount of our 5.80% Senior Notes due 2011, or the "Fixed Rate Notes," and $225,000,000 aggregate principal amount of our Senior Floating Rate Notes due 2009, or the "Floating Rate Notes"; collectively with the Fixed Rate Notes, the "Notes." The Floating Rate Notes will bear interest at a rate per year equal to the three-month LIBOR (as defined herein) plus 0.55%. The Fixed Rate Notes will mature on March 15, 2011. The Floating Rate Notes will mature on March 16, 2009. We will pay interest on the Fixed Rate Notes on each June 15 and December 15, commencing June 15, 2006. Interest on the Floating Rate Notes will be paid quarterly on each March 16, June 16, September 16, and December 16 commencing on March 16, 2006.

        We may redeem the Fixed Rate Notes in whole or in part prior to their maturity at any time at the redemption price described in "Description of the Notes—Redemption—Optional Redemption of Notes." We may not redeem the Floating Rate Notes prior to their maturity.

        The Notes are our unsecured senior obligations and rank equally with all of our other unsecured, unsubordinated indebtedness from time to time outstanding.

        The Notes are not expected to be listed on any securities exchange or included in any quotation system.

        This prospectus supplement and the related prospectus include additional information about the terms of the Notes, including covenants.

        See "Risk Factors," beginning on page S-3 of this prospectus supplement and on page 2 of the accompanying prospectus, for a discussion of certain risks you should consider before investing in the Notes.

        Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined that this prospectus supplement or the accompanying prospectus is accurate or complete. Any representation to the contrary is a criminal offense.

 
   Public offering
price
   Underwriting
discount
   Proceeds, before
expenses, to us
  
Per Fixed Rate Note     99.900 %   0.600 %   99.300 %
Per Floating Rate Note     100.000 %   0.350 %   99.650 %
Total   $ 474,750,000   $ 2,287,500   $ 472,462,500  

        The public offering price set forth above does not include accrued interest, if any. Interest on the Notes will accrue from December 14, 2005 and must be paid if the Notes are delivered after December 14, 2005.

        The underwriters expect to deliver the Notes through the facilities of the Depository Trust Company against payment in New York, New York on or about December 14, 2005.

Joint Book-Running Managers

Merrill Lynch & Co. UBS Investment Bank

Co-Managers
     
HSBC RBC Capital Markets Scotia Capital

The date of this prospectus supplement is December 7, 2005


TABLE OF CONTENTS

 
   Page
    
   Page
Prospectus Supplement   Prospectus

Forward-Looking Statements
 
ii
 
About this Prospectus
 
1
Summary   S-1   Forward-Looking Statements   1
Risk Factors   S-3   iStar Financial Inc.   2
Ratio of Earnings to Fixed Charges   S-4   Risk Factors   2
Use of Proceeds   S-5   Ratios of Earnings to Combined Fixed    
Description of Other Indebtedness   S-6       Charges and Preferred Stock Dividends    
Description of the Notes   S-9       and Earnings to Fixed Charges   9
Certain U.S. Federal Income Tax       Use of Proceeds   9
  Consequences   S-28   Description of Debt Securities   10
Underwriting   S-32   Description of Warrants   12
Legal Matters   S-33   Description of Common Stock and    
Experts   S-33       Preferred Stock   13
        Description of Depositary Shares   18
        Certain U.S. Federal Income Tax Consequences   19
        Plan of Distribution   36
        Legal Matters   37
        Experts   37
        Incorporation of Certain Documents By Reference   38
        Information We File   38

        You should only rely on the information contained or incorporated by reference in this prospectus supplement and the accompanying prospectus. We have not, and the underwriters have not, authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. We are not, and the underwriters are not, making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information appearing in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference is accurate only as of their respective dates. Our business, financial condition, results of operations and prospects may have changed since those dates.

        Unless otherwise stated or the context requires otherwise, references to "iStar," "the Company," "we," "us" and "our" are to iStar Financial Inc. and its consolidated subsidiaries.


Creative Capital Solutions and the iStar Financial logo are
registered trade marks of iStar Financial Inc.


FORWARD-LOOKING STATEMENTS

        We make statements in this prospectus supplement, the accompanying prospectus and the documents we incorporate by reference that are considered "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933, as amended and Section 21E of the Securities Exchange Act of 1934, as amended which are usually identified by the use of words such as "will," "anticipates," "believes," "estimates," "expects," "projects," "plans," "intends," "should" or similar expressions. We intend these forward-looking statements to be covered by the safe harbor provisions for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995 and are including this statement for purposes of complying with those safe harbor provisions. These forward-looking statements reflect our current views about our plans, strategies and prospects, which are based on the information currently available to us and on assumptions we have made. Although we believe that our plans, intentions and expectations as reflected in or suggested by those forward-looking statements are reasonable, we can give no assurance that the plans, intentions or expectations will be achieved. We have discussed in this prospectus supplement, the accompanying prospectus and the documents we incorporate by reference some important risks, uncertainties and contingencies which could cause our actual results, performance or achievements to be materially different from the forward-looking statements we make in these documents.

        We assume no obligation to update publicly any forward-looking statements, whether as a result of new information, future events or otherwise. In evaluating forward-looking statements, you should consider these risks and uncertainties, together with the other risks described from time to time in our reports and documents filed with the SEC, and you should not place undue reliance on those statements.

ii


Summary

Issuer   iStar Financial Inc.

Securities Offered
 
$250,000,000 principal amount of 5.80% Senior Notes due 2011 and $225,000,000 principal amount of Senior Floating Rate Notes due 2009.

Maturity
 
Unless redeemed earlier, the Fixed Rate Notes will mature on March 15, 2011. The Floating Rate Notes will mature on March 16, 2009.

Interest Rate
 
The Fixed Rate Notes will bear interest at 5.80% per year (calculated using a 360-day year comprised of twelve 30-day months).

 
 
The Floating Rate Notes will bear interest at a rate per year equal to three-month LIBOR, plus 0.55% (calculated on the basis of a 360-day year using the actual number of days elapsed from and including an interest payment date to but excluding the next succeeding interest payment date). Interest on the Floating Rate Notes will be reset quarterly.

Interest Payment Dates
 
Interest on the Fixed Rate Notes will be paid on each June 15 and December 15, commencing June 15, 2006. Interest on the Floating Rate Notes will be paid quarterly on each March 16, June 16, September 16 and December 16, commencing on March 16, 2006. Interest on the Notes will accrue from the date of issuance.

Ranking
 
The Notes are our unsecured senior obligations and rank equally with our existing and future unsecured senior indebtedness and, to the extent we incur subordinated indebtedness in the future, senior to such indebtedness. The Notes will be effectively subordinated to all of our secured indebtedness and all indebtedness of our subsidiaries. As of September 30, 2005, the aggregate amount of our outstanding consolidated indebtedness was approximately $5.2 billion, of which approximately $666.5 million was debt of our subsidiaries. After giving pro forma effect to this offering and the repayment of a $135.0 million secured term loan which occurred on October 17, 2005, our outstanding indebtedness would have been approximately $5.2 billion and our subsidiaries would have had approximately $531.5 million of indebtedness outstanding at September 30, 2005.

Optional Redemption
 
We may redeem the Fixed Rate Notes in whole or in part prior to their maturity at any time at the redemption price described in "Description of the Notes—Redemption—Optional Redemption of Notes." We may not redeem the Floating Rate Notes prior to their maturity.

Certain Indenture Provisions
 
The indenture governing the Notes contains covenants limiting our and our subsidiaries' ability to:

 
 
•
 
incur indebtedness;

 
 
•
 
maintain unencumbered assets; or

 
 
•
 
merge or consolidate with another person.

 
 
These covenants are subject to a number of important limitations and exceptions. See "Description of the Notes—Certain Covenants."
Risk Factors   Investing in the Notes involves substantial risks. See "Risk Factors" in this prospectus supplement and in the accompanying prospectus for a description of certain risks you should consider before investing in the Notes.

Use of Proceeds
 
We intend to use the net proceeds to repay outstanding indebtedness under our unsecured revolving credit facility. See "Use of Proceeds."

S-1


iSTAR FINANCIAL INC.

        We are the leading publicly-traded finance company focused on the commercial real estate industry. We provide custom-tailored financing to high-end private and corporate owners of real estate, including senior and junior mortgage debt, senior and mezzanine corporate capital, and corporate net lease financing. Our objective is to generate consistent and attractive returns on our invested capital by providing innovative and value-added financing solutions to our customers. We are taxed as a real estate investment trust ("REIT") for U.S. federal income tax purposes.

        Our principal executive offices are located at 1114 Avenue of the Americas, New York, New York 10036, and our telephone number is (212) 930-9400. Our website is www.istarfinancial.com. The information on our website is not considered part of this prospectus supplement or the accompanying prospectus. Our five primary regional offices are located in Atlanta, Boston, Dallas, Hartford and San Francisco. iStar Asset Services, our loan servicing subsidiary, is located in Hartford, and iStar Real Estate Services, our corporate facilities management division, is headquartered in Atlanta.

S-2


RISK FACTORS

        This section describes some, but not all, of the risks of purchasing Notes in the offering. The prospectus to which this supplement relates also contains a Risk Factors section beginning on page 2 of that prospectus. You should carefully consider these risks, in addition to the other information contained or incorporated by reference in this document, before purchasing Notes. You should carefully review the factors discussed below and the cautionary statements referred to in "Forward-Looking Statements."

We Have Other Indebtedness

        As of September 30, 2005, on a pro forma basis after giving effect to this offering and the repayment of a $135.0 million secured term loan on October 17, 2005, our outstanding debt would have been approximately $5.2 billion. Our ability to make scheduled payments of principal or interest on, or to refinance, our indebtedness depends on our future performance, which, to a certain extent, is subject to general economic, financial, competitive and other factors beyond our control.

The Notes Will Be Structurally Subordinated to Subsidiary Debt

        The Notes are not guaranteed by any of our subsidiaries. Our subsidiaries hold a substantial portion of our assets. After giving pro forma effect to this offering and the repayment of a $135.0 million secured term loan on October 17, 2005, our subsidiaries would have had approximately $531.5 million of indebtedness outstanding at September 30, 2005. Creditors of a subsidiary are entitled to be paid what is due to them before assets of the subsidiary become available for creditors of its parent.

As a REIT, We Must Distribute a Portion of Our Income to Our Stockholders

        We must distribute annually at least 90% of our taxable net income to our stockholders to maintain our REIT qualification. As a result, those earnings will not be available to pay principal or interest on the Notes. Our taxable net income has historically been lower than the cash flow generated by our business activities, primarily because our taxable net income is reduced by non-cash expenses, such as depreciation and amortization. As a result, our dividend payout ratio as a percentage of free cash flow has generally been lower than our payout ratio as a percentage of taxable net income. However, our primary unsecured revolving credit facility permits us to distribute up to the greater of 100% of our adjusted earnings or such dividends as may be necessary to maintain our REIT qualification.

There is No Public Market for the Notes

        If the Notes are traded after their initial issuance, they may trade at a discount from their initial offering price, depending upon prevailing interest rates, the market for similar securities, our performance and certain other factors. Historically, there has been substantial volatility in the prices of corporate debt securities, and the price of the Notes is likely to be affected by factors which affect the price of corporate debt securities generally. We do not intend to apply for listing of the Notes on any securities exchange or for inclusion of the Notes on any automated quotation system.

S-3


RATIO OF EARNINGS TO FIXED CHARGES

 
    
   Years Ended December 31,
 
   Nine Months Ended
September 30, 2005
 
   2004
   2003
   2002
   2001
   2000
Ratio of earnings to fixed charges and preferred stock dividends(1)   1.7x(2)   1.5x(3)   2.0x   1.7x   1.8x   1.7x
Ratio of earnings to fixed charges(1)   1.9x(2)   1.8x(3)   2.4x   2.1x   2.2x   2.1x
(1)
For the purposes of calculating the ratio of earnings to fixed charges, "earnings" consist of income from continuing operations before adjustment for minority interest in consolidated subsidiaries, or income or loss from equity investees, income taxes and cumulative effect of change in accounting principle plus "fixed charges" and certain other adjustments. "Fixed charges" consist of interest incurred on all indebtedness (including amortization of original issue discount) and the implied interest component of our rent obligations in the periods presented.

(2)
Includes the effect of STARs asset-backed notes redemption charge of $44.3 million. Excluding this charge, the ratio of earnings to fixed charges and preferred stock dividends and the ratio of earnings to fixed charges would have been 1.8x and 2.1x respectively.

(3)
Includes the effect of chief executive officer, chief financial officer and ACRE Partners compensation charges of $106.9 million, 8.75% Senior Notes due 2008 redemption charge of $11.5 million and, for the ratio of earnings to fixed charges and preferred dividends, preferred stock redemption charge of $9.0 million. Excluding these charges, the ratio of earnings to fixed charges and preferred stock dividends and the ratio of earnings to fixed charges would have been 2.0x and 2.3x, respectively.

S-4


USE OF PROCEEDS

        The net proceeds from the sale of the Notes, after deducting underwriting discounts and commissions and fees and expenses related to the offering, are expected to be approximately $471.7 million, assuming we issue $475 million of Notes. We intend to use the net proceeds to repay outstanding indebtedness under our unsecured revolving credit facility. All of this indebtedness was incurred during the past year for investment and working capital purposes. At September 30, 2005, the weighted average interest rate of the borrowings we intend to repay was 4.74%, and the weighted average maturity was 2.6 years. We use our unsecured revolving credit facility to fund our business on an ongoing basis and we intend continue to do so in the future. Amounts being repaid under our unsecured revolving credit facility will be available for future borrowings. Affiliates of some of the underwriters of this offering are lenders under our unsecured line of credit and will, therefore, receive a portion of the net proceeds from the sale of the Notes. For more information, please see the "Underwriting" section of this prospectus supplement.

S-5


DESCRIPTION OF OTHER INDEBTEDNESS

        The table below reflects our debt obligations under various arrangements as of September 30, 2005. All of the indebtedness shown below which has not subsequently been repaid is non-recourse to iStar Financial, the parent company, except that iStar Financial is the borrower under the unsecured revolving credit facility shown below; iStar Financial is the issuer of the 8.75%, 7.95%, 7.00%, 6.50%, 6.05%, 6.00%, 5.70%, 5.375%, 5.15%, 5.125%, 4.875%, and senior floating rate unsecured notes shown below; and iStar Financial has provided limited guarantees of certain subsidiary borrowings. Specifically, iStar Financial is a guarantor of a $76.1 million subsidiary financing due January 2006 and a guarantor of up to $30 million under the $700 million secured facility due January 2007. In addition, iStar Financial provides guarantees under non-recourse subsidiary borrowings for customary carve-out matters such as fraud, misappropriation and voluntary bankruptcy proceedings.

        We are subject to a number of covenants in our borrowing arrangements. These covenants are both financial and non-financial in nature. Significant financial covenants include limitations on our ability to incur indebtedness beyond specified levels. Significant non-financial covenants include a requirement in some of our publicly-held debt securities that we offer to repurchase those securities at a premium if we undergo a change of control.

S-6

        As of September 30, 2005 we had debt obligations under various arrangements as follows (in thousands):

 
    
   Carrying Value as of
    
    
 
   Maximum
Amount
Available
   September 30,
2005
   December 31,
2004
   Stated Interest Rates(1)
   Scheduled
Maturity Date

Unsecured revolving credit facilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
    Line of credit   $ 1,500,000   $ 930,000   $ 840,000   LIBOR + 0.875%   April 2008(2)
   
 
 
       
Secured revolving credit facilities:                          
    Line of credit     —     —     —   LIBOR + 1.50% — 2.05%   March 2005
    Line of credit     700,000     11,325     67,775   LIBOR + 1.40% — 2.15%   January 2007(3)
    Line of credit     —     —     10,811   LIBOR + 1.50% — 2.25%   August 2005
    Line of credit     —     —     —   LIBOR + 1.50% — 2.25%   September 2005
   
 
 
       
   
Total revolving credit facilities
 
 
2,200,000
 
 
941,325
 
 
918,586
 
 
 
 

Unsecured notes:
 
 
 
 
 
 
 
 
 
 
 
 
 
    LIBOR + 0.39% Senior Notes     400,000     —   LIBOR + 0.39%   March 2008
    LIBOR + 1.25% Senior Notes     200,000     200,000   LIBOR + 1.25%   March 2007
    4.875% Senior Notes     350,000     350,000   4.875%   January 2009
    5.125% Senior Notes     250,000     250,000   5.125%   April 2011
    5.15% Senior Notes     700,000     —   5.15%   March 2012
    5.375% Senior Notes     250,000     —   5.375%   April 2010
    5.70% Senior Notes     367,022     250,000   5.70%   March 2014
    6.00% Senior Notes     350,000     350,000   6.00%   December 2010
    6.05% Senior Notes     250,000     —   6.05%   April 2015
    6.50% Senior Notes     150,000     150,000   6.50%   December 2013
    7.00% Senior Notes     185,000     185,000   7.00%   March 2008
    7.70% Notes(4)     —     100,000   7.70%   July 2017
    7.95% Notes(4)     50,000     50,000   7.95%   May 2006
    8.75% Notes     240,000     240,000   8.75%   August 2008
         
 
       
    Total unsecured notes     3,742,022     2,125,000        
    Less: debt discount     (78,469 )   (56,913 )      
    Plus: impact of pay-floating swap agreements     (21,778 )   (3,652 )      
         
 
       
   
Total unsecured notes
 
 
3,641,775
 
 
2,064,435
 
 
 
 

Secured term loans:
 
 
 
 
 
 
 
 
 
 
 
 
 
    Secured by Corporate Tenant Lease ("CTL") asset     59,614     60,180   6.41%   January 2013
    Secured by CTL assets     —     76,670   6.55%   December 2005(5)
    Secured by CTL asset     133,349     136,512   7.44%   April 2009
    Secured by CTL asset     135,000     135,000   LIBOR + 1.75%   October 2008(6)
    Secured by CTL assets     146,365     148,600   6.80% — 8.80%   Various through 2026
    Secured by corporate bond
investments		     76,089     129,446   LIBOR + 1.05% — 1.50%   January 2006
         
 
       
    Total term loans     550,417     686,408        
    Less: net debt premium     6,800     7,065        
         
 
       
    Total secured term loans     557,217     693,473        

iStar Asset Receivables secured notes:
 
 
 
 
 
 
 
 
 
 
 
 
 
  STARs Series 2002-1:                    
    Class A2     —     202,052   LIBOR + 0.38%   December 2009(7)
    Class B     —     39,955   LIBOR + 0.65%   April 2011(7)
    Class C     —     26,637   LIBOR + 0.75%   May 2011(7)
    Class D     —     21,310   LIBOR + 0.85%   January 2012(7)
    Class E     —     42,619   LIBOR + 1.235%   January 2012(7)
    Class F     —     26,637   LIBOR + 1.335%   January 2012(7)
    Class G     —     21,309   LIBOR + 1.435%   January 2012(7)
    Class H     —     26,637   6.35%   January 2012(7)
    Class J     —     26,637   6.35%   May 2012(7)
    Class K     —     26,637   6.35%   May 2012(7)
         
 
       
    Total STARs Series 2002-1     —     460,430        
    Less: debt discount     —     (3,734 )      
         
 
       

S-7

 
    
   Carrying Value as of
    
    
 
    
   September 30,
2005
   December 31,
2004
   Stated Interest Rates(1)
   Scheduled
Maturity Date
 
STARs Series 2003-1:
 
 
 
 
 
 
 
 
 
 
    Class A1     —     113,309   LIBOR + 0.25%   October 2005(7)
    Class A2     —     225,227   LIBOR + 0.35%   August 2010(7)
    Class B     —     16,744   LIBOR + 0.55%   July 2011(7)
    Class C     —     18,418   LIBOR + 0.65%   April 2012(7)
    Class D     —     11,720   LIBOR + 0.75%   October 2012(7)
    Class E     —     13,395   LIBOR + 1.05%   May 2013(7)
    Class F     —     13,395   LIBOR + 1.10%   June 2013(7)
    Class G     —     11,720   LIBOR + 1.25%   June 2013(7)
    Class H     —     11,721   4.97%   June 2013(7)
    Class J     —     13,394   5.07%   June 2013(7)
    Class K     —     23,441   5.56%   June 2013(7)
       
 
       
    Total STARS Series 2003-1     —     472,484        
       
 
       
    Total iStar Asset Receivables secured notes     —     929,180        

Other debt obligations(8)
 
 
100,000
 
 
—
 
LIBOR + 1.50%
 
September 2035
    Less: debt discount     (2,037 )   —        
       
 
       
    Total other debt obligations     97,963     —        
       
 
       
Total debt obligations   $ 5,238,280   $ 4,605,674        
       
 
       

Explanatory Notes:

(1)
Most variable-rate debt obligations are based on 30-day LIBOR and reprice monthly. The 30-day LIBOR rate on September 30, 2005 was 3.86%. However, some variable-rate debt obligations are based on 90-day LIBOR and reprice every 3 months. The 90-day LIBOR rate on September 30, 2005 was 4.07%.

(2)
Maturity date reflects a one-year extension at our option. On September 16, 2005, the commitment under this facility was increased to $1.5 billion under the accordion feature of the facility.

(3)
Maturity date reflects a one-year "term-out" extension at the Company's option.

(4)
These obligations were assumed as part of the acquisition of our former subsidiary, TriNet Corporate Realty Trust Inc., or TriNet. As part of the accounting for the purchase, these fixed-rate obligations were considered to have stated interest rates which were below the then-prevailing market rates at which TriNet could issue new debt obligations and, accordingly, the Company ascribed a market discount to each obligation. Such discounts are amortized as an adjustment to interest expense using the effective interest method over the related term of the obligations. As adjusted, the effective annual interest rates on these obligations were 9.51% and 9.04% for the 7.70% Notes and 7.95% Notes, respectively.

(5)
On September 1, 2005, we repaid this $76.0 million mortgage on 11 CTL investments which was open to prepayment without penalty.

(6)
On October 17, 2005, we repaid this $135.0 million mortgage with an original maturity date of October 2008. We paid a 0.5% prepayment penalty at the time of prepayment.

(7)
On September 28, 2005, we fully repaid the STARs Series 2002-1 and STARs Series 2003-1 Notes which had an aggregate outstanding principal balance of approximately $620.7 million on the date of repayment. We incurred one-time cash costs, including prepayment and other fees, of approximately $6.8 million and a non-cash charge of approximately $37.5 million to write-off deferred financing fees and expenses.

(8)
On September 14, 2005, we completed the issuance of $100.0 million in unsecured floating rate trust preferred securities through a newly formed statutory trust, iStar Financial Statutory Trust I, that is a subsidiary of our Company. The securities are subordinate to our senior unsecured debt and bear interest at a rate of LIBOR + 1.50%. The trust preferred securities are redeemable at our option, in whole or in part, with no prepayment premium any time after October 2010.

S-8


DESCRIPTION OF THE NOTES

        The Company will issue the Notes under an indenture dated as of February 5, 2001 between itself and US Bank Trust National Association, as Trustee (the "Trustee"), and a supplemental indenture with respect to each series of the Notes between itself and the Trustee dated as of December 14, 2005 (the indenture, together with the supplemental indenture for the Notes, as applicable, being the "Indenture"). The terms of each supplemental indenture are substantially similar, but differ with regard to a few items, including the maturity date, interest rate and redemption provisions, as more fully described below. The following is a summary of the material provisions of the Indenture. It does not include all of the provisions of the Indenture. Although for convenience the Fixed Rate Notes and the Floating Rate Notes are referred to as the "Notes," each will be issued as a separate series and will not together have any class voting rights. Accordingly, for purposes of this Description of Notes, references to the "Notes" shall be deemed to refer to each series of Notes separately, and not to the Fixed Rate Notes and the Floating Rate Notes on any combined basis. The following description of the particular terms of the Notes supplements the description in the accompanying prospectus of the general terms and provisions of our debt securities. To the extent that the following description of Notes is inconsistent with that general description in the prospectus, the following description replaces that in the prospectus. We urge you to read the Indenture because it defines your rights. The terms of the Notes include those stated in the Indenture and those made part of the Indenture by reference to the Trust Indenture Act of 1939, as amended (the "TIA"). A copy of the form of Indenture has been filed as an exhibit to the Registration Statement of which this Prospectus Supplement is a part. You can find definitions of certain capitalized terms used in this description under "—Certain Definitions." For purposes of this section, references to the "Company" or "our" include only iStar Financial Inc. and not its subsidiaries.

        The Notes will be unsecured obligations of the Company, ranking equally in right of payment with all other senior unsecured obligations of the Company from time to time outstanding.

        The Company will issue the Notes in fully registered form in denominations of $1,000 and integral multiples of $1,000. The Trustee will initially act as paying agent and registrar for the Notes. The Notes may be presented for registration or transfer and exchange at the offices of the registrar. The Company may change any paying agent and registrar without notice to holders of the Notes (the "Holders"). The Company will pay principal (and premium, if any) on the Notes at the Trustee's corporate office in New York, New York. At the Company's option, interest may be paid at the Trustee's corporate trust office or by check mailed to the registered address of Holders.

Principal, Maturity and Interest

        The Notes are series of securities issued under the Indenture. The Indenture permits the Company to "re-open" each series without the consent of the Holders, and issue additional Notes of the same series at any time on the same terms (other than issuance date, initial interest accrual date and in some cases, the first interest payment dates) and conditions and with the same CUSIP number as the Notes being issued in this offering. The Fixed Rate Notes will mature on March 15, 2011 and the Floating Rate Notes will mature on March 16, 2009. Interest on the Fixed Rate Notes is calculated on the basis of a 360-day year comprised of twelve 30-day months. Interest on the Floating Rate Notes is calculated on the basis of a 360-day year using the actual number of days elapsed from and including an interest payment date to but excluding the next succeeding interest payment date.

        Interest on the Fixed Rate Notes will be payable semiannually in cash on each June 15 and December 15, commencing on June 15, 2006 to the persons who are registered Holders at the close of business on each June 1 and December 1.

        Interest on the Floating Rate Notes will be payable quarterly in cash on each March 16, June 16, September 16 and December 16, commencing on March 16, 2006 to the persons who are registered

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Holders at the close of business on the March 1, June 1, September 1 and December 1 immediately preceding the applicable interest payment date.

        If any interest payment date on a Note other than the maturity date is not a Business Day, such interest payment date will be postponed to the next succeeding Business Day, except that (in the case of the Floating Rate Notes) if such Business Day falls in the next succeeding calendar month, such interest payment date will be the immediately preceding Business Day. If the maturity date of a Note or an interest payment date of a Fixed Rate Note falls on a day that is not a Business Day, the required payment of principal and interest will be made on the next succeeding Business Day as if made on the date such payment was due, and no interest will accrue on such payment for the period from and after the maturity date or such interest payment date, as the case may be, to the date of such payment on the next succeeding Business Day. Interest on the Notes will accrue from the most recent date to which interest has been paid or, if no interest has been paid, from and including the date of issuance.

        The Floating Rate Notes will bear interest at a rate per year, reset quarterly (the "interest reset period" and the first date in such period, the "interest reset date"), equal to three-month LIBOR plus 0.55%, to be determined by the calculation agent. The interest rate on the Floating Rate Notes applicable to each interest reset period commencing on the related interest reset date, or the original issue date in the case of the initial interest period, will be the rate determined as of the applicable interest determination date. The "interest determination date" will be the second London business day immediately preceding the original issue date, in the case of the initial interest reset period, or thereafter the applicable interest reset date.

        US Bank Trust National Association, or its successor appointed by us, will act as calculation agent with respect to the Floating Rate Notes. Three-month LIBOR will be determined by the calculation agent as of the applicable interest determination date in accordance with the following provisions:

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        All percentages resulting from any calculation of any interest rate for the Floating Rate Notes will be rounded, if necessary, to the nearest one hundred thousandth of a percentage point, with five one-millionths of a percentage point rounded upward and all dollar amounts will be rounded to the nearest cent, with one-half cent being rounded upward.

        Promptly upon such determination, the calculation agent will notify us and the Trustee (if the calculation agent is not the Trustee) of the interest rate for the new interest reset period. Upon request of a holder of the Floating Rate Notes, the calculation agent will provide to such holder the interest rate in effect on the date of such request and, if determined, the interest rate for the next interest reset period.

        All calculations made by the calculation agent for the purposes of calculating interest on the Floating Rate Notes shall be conclusive and binding on the holders and us, absent manifest error.

        The Notes will not be entitled to the benefit of any mandatory sinking fund.

Redemption

Floating Rate Notes

        The Floating Rate Notes may not be redeemed prior to their maturity.

Optional Redemption of Fixed Rate Notes

        The Fixed Rate Notes may be redeemed or purchased in whole or in part at the Company's option at any time prior to the maturity of the Fixed Rate Notes at a price equal to 100% of the principal amount thereof plus the Applicable Premium as of, and accrued but unpaid interest, if any, to the date of the redemption or purchase (the "Redemption Date") (subject to the right of Holders of record on the relevant record date to receive interest due on the relevant interest payment date).

        "Applicable Premium" means, with respect to the Fixed Rate Notes at any Redemption Date, the greater of: (1) 1.0% of the principal amount of such Fixed Rate Note; and (2) the excess of (a) the present value at such Redemption Date of (i) the principal amount of such Fixed Rate Note on the redemption date plus (ii) all required remaining scheduled interest payments due on such Fixed Rate Note through March 15, 2011, computed using a discount rate equal to the Treasury Rate plus 25 basis points; over (b) the principal amount of such Fixed Rate Note on such Redemption Date. Calculation of the Applicable Premium will be made by the Company or on behalf of the Company by such Person as the Company shall designate; provided, however, that such calculation shall not be a duty or obligation of the Trustee.

        "Treasury Rate" means, with respect to a Redemption Date, the yield to maturity at the time of computation of United States Treasury securities with a constant maturity (as compiled and published in the most recent Federal Reserve Statistical Release H.15(519) that has become publicly available on the third Business Day prior to our providing notice of redemption (or, if such Statistical Release is no longer published, any publicly available source of similar market data)) most nearly equal to the period from such Redemption Date to the maturity date of the Fixed Rate Notes; provided, however, that if

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the period from such Redemption Date to the maturity date is not equal to the constant maturity of the United States Treasury security for which a weekly average yield is given, the Treasury Rate shall be obtained by linear interpolation (calculated to the nearest one-twelfth of a year) from the weekly average yields of United States Treasury securities for which such yields are given, except that if the period from such Redemption Date to the maturity date is less than one year, the weekly average yield on actually traded United States Treasury securities adjusted to a constant maturity of one year shall be used.

Selection and Notice of Redemption

        In the event that the Company chooses to redeem less than all of the Fixed Rate Notes, selection of the Fixed Rate Notes for redemption will be made by the Trustee either:


        No Fixed Rate Notes of a principal amount of $1,000 or less shall be redeemed in part. Notice of redemption will be mailed by first-class mail at least 30 but not more than 60 days before the Redemption Date to each Holder of Fixed Rate Notes to be redeemed at its registered address. On and after the Redemption Date, interest will cease to accrue on Fixed Rate Notes or portions thereof called for redemption as long as the Company has deposited with the paying agent funds in satisfaction of the applicable redemption price.

Certain Covenants

        The following covenants in the Indenture apply to the Notes; provided, however, that the covenants described under "Limitation on Incurrence of Additional Indebtedness" and "Maintenance of Total Unencumbered Assets" will not apply if, and only for so long as, (1) the Notes are rated BBB or Baa2, or higher, by at least two of the following three rating agencies: Standard & Poor's Ratings Group, Moody's Investors Services, Inc. and Fitch Ratings and (2) no Default or Event of Default has occurred and is continuing.

        Limitation on Incurrence of Additional Indebtedness.    The Company will not, and will not permit any of its Subsidiaries to, directly or indirectly, create, incur, assume, guarantee, become liable, contingently or otherwise, with respect to, or otherwise become responsible for payment of (collectively, "incur") any Indebtedness (including, without limitation, Acquired Indebtedness) other than Permitted Indebtedness.

        Notwithstanding the foregoing, if no Default or Event of Default shall have occurred and be continuing at the time of or as a consequence of the incurrence of any such Indebtedness, the Company or any of its Subsidiaries may incur Indebtedness (including, without limitation, Acquired Indebtedness), in each case if on the date of the incurrence of such Indebtedness, after giving effect to the incurrence thereof, the Consolidated Fixed Charge Coverage Ratio of the Company is greater than 1.5 to 1.0.

        Maintenance of Total Unencumbered Assets.    The Company and its Subsidiaries will maintain Total Unencumbered Assets of not less than 120% of the aggregate outstanding principal amount of the Unsecured Indebtedness of the Company and its Subsidiaries, in each case on a consolidated basis.

        Merger, Consolidation and Sale of Assets.    The Company will not, in a single transaction or series of related transactions, consolidate or merge with or into any Person, or sell, assign, transfer, lease, convey or otherwise dispose of (or cause or permit any Subsidiary of the Company to sell, assign, transfer, lease, convey or otherwise dispose of) all or substantially all of the Company's assets (determined on a

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consolidated basis for the Company and the Company's Subsidiaries) whether as an entirety or substantially as an entirety to any Person unless:

        For purposes of the foregoing, the transfer (by lease, assignment, sale or otherwise, in a single transaction or series of transactions) of all or substantially all of the properties or assets of one or more Subsidiaries of the Company the Capital Stock of which constitutes all or substantially all of the properties and assets of the Company, shall be deemed to be the transfer of all or substantially all of the properties and assets of the Company.

        The Indenture will provide that upon any consolidation or merger or any transfer, lease, conveyance or other disposition of all or substantially all of the assets of the Company in accordance with the foregoing, in which the Company is not the continuing corporation, the successor Person formed by such consolidation or into which the Company is merged or to which such transfer, lease, conveyance or other disposition is made shall succeed to, and be substituted for, and may exercise every right and power of, the Company under the Indenture and the Notes with the same effect as if such surviving entity had been named as such.

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        Reports to Holders.    Whether or not required by the rules and regulations of the Commission, so long as any Notes are outstanding, the Company will furnish the Holders of Notes:

        In addition, whether or not required by the rules and regulations of the Commission, the Company will file a copy of all such information and reports with the Commission for public availability within the time periods specified in the Commission's rules and regulations (unless the Commission will not accept such a filing) and make such information available to securities analysts and prospective investors upon request. In addition, the Company has agreed that, for so long as any Notes remain outstanding, it will furnish to the Holders and to securities analysts and prospective investors, upon their request, the information required to be delivered pursuant to Rule 144A(d)(4) under the Securities Act.

Events of Default

        The following events are defined in the Indenture as "Events of Default" with respect to the Notes of each particular series:

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        If an Event of Default (other than an Event of Default specified in clause (5) above with respect to the Company) shall occur and be continuing, the Trustee or the Holders of at least 25% in principal amount of outstanding Notes of the applicable series of Notes, may declare the principal of and accrued interest on all the Notes of such series to be due and payable by notice in writing to the Company and the Trustee specifying the respective Event of Default and that it is a "notice of acceleration" (the "Acceleration Notice"), and the same shall become immediately due and payable.

        If an Event of Default specified in clause (5) above with respect to the Company occurs and is continuing, then all unpaid principal of, and premium, if any, and accrued and unpaid interest on all of the outstanding Notes of the applicable series of Notes shall ipso facto become and be immediately due and payable without any declaration or other act on the part of the Trustee or any Holder.

        The Indenture will provide that, at any time after a declaration of acceleration with respect to Notes as described in the preceding paragraph, the Holders of a majority in principal amount of the Notes of the applicable series of Notes may rescind and cancel such declaration and its consequences:

        The Holders of a majority in principal amount of the Notes of a series may waive any existing Default or Event of Default under the Indenture with respect to this series, and its consequences, except a default in the payment of the principal of or interest on any Notes.

        Holders of the Notes may not enforce the Indenture or the Notes except as provided in the Indenture and under the TIA. Subject to the provisions of the Indenture relating to the duties of the Trustee, the Trustee is under no obligation to exercise any of its rights or powers under the Indenture at the request, order or direction of any of the Holders, unless such Holders have offered to the Trustee reasonable indemnity. Subject to all provisions of the Indenture and applicable law, the Holders of a majority in aggregate principal amount of the then outstanding Notes have the right to direct the time, method and place of conducting any proceeding for any remedy available to the Trustee or exercising any trust or power conferred on the Trustee.

        Under the Indenture, the Company is required to provide an officers' certificate to the Trustee promptly upon any such officer obtaining knowledge of any Default or Event of Default (provided that such officers shall provide such certification at least annually whether or not they know of any Default or Event of Default) that has occurred and, if applicable, describe such Default or Event of Default and the status thereof.

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Legal Defeasance and Covenant Defeasance

        The Company may, at its option and at any time, elect to have its obligations discharged with respect to the outstanding Notes of a particular series ("Legal Defeasance"). Such Legal Defeasance means that the Company shall be deemed to have paid and discharged the entire indebtedness represented by the outstanding Notes of such series, except for:

        In addition, the Company may, at its option and at any time, elect to have the obligations of the Company released with respect to certain covenants that are described in the Indenture ("Covenant Defeasance") and thereafter any omission to comply with such obligations shall not constitute a Default or Event of Default with respect to the Notes. In the event Covenant Defeasance occurs, certain events (not including non-payment, bankruptcy, receivership, reorganization and insolvency events) described under "Events of Default" will no longer constitute an Event of Default with respect to the applicable series of Notes.

        In order to exercise either Legal Defeasance or Covenant Defeasance:

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        Notwithstanding the foregoing, the opinion of counsel required by clause (2) above with respect to a Legal Defeasance need not be delivered if all Notes of the applicable series not theretofore delivered to the Trustee for cancellation (1) have become due and payable or (2) will become due and payable on the maturity date within one year under arrangements satisfactory to the Trustee for the giving of notice of redemption by the Trustee in the name, and at the expense, of the Company.

Satisfaction and Discharge

        The Indenture will be discharged and will cease to be of further effect (except as to surviving rights or registration of transfer or exchange of the Notes, as expressly provided for in the Indenture) as to all outstanding Notes of a particular series when:

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Modification of the Indenture

        From time to time, the Company and the Trustee, without the consent of the Holders, may amend the Indenture for certain specified purposes, including curing ambiguities, defects or inconsistencies, so long as such change does not, in the opinion of the Trustee, adversely affect the rights of any of the Holders in any material respect. In formulating its opinion on such matters, the Trustee will be entitled to rely on such evidence as it deems appropriate, including, without limitation, solely on an opinion of counsel. Other modifications and amendments of the Indenture may be made with the consent of the Holders of a majority in principal amount of the then outstanding Fixed Rate Notes or Floating Rate Notes, as the case may be voting as separate classes, issued under the Indenture, except that, without the consent of each Holder affected thereby, no amendment may:

Governing Law

        The Indenture will provide that it and the Notes will be governed by, and construed in accordance with, the laws of the State of New York but without giving effect to applicable principles of conflicts of law to the extent that the application of the law of another jurisdiction would be required thereby.

The Trustee

        The Indenture will provide that, except during the continuance of an Event of Default, the Trustee will perform only such duties as are specifically set forth in the Indenture. During the existence of an Event of Default, the Trustee will exercise such rights and powers vested in it by the Indenture, and use the same degree of care and skill in its exercise as a prudent man would exercise or use under the circumstances in the conduct of his own affairs.

        The Indenture and the provisions of the TIA contain certain limitations on the rights of the Trustee, should it become a creditor of the Company, to obtain payments of claims in certain cases or to realize on certain property received in respect of any such claim as security or otherwise. Subject to the TIA, the Trustee will be permitted to engage in other transactions; provided that if the Trustee acquires any conflicting interest as described in the TIA, it must eliminate such conflict or resign.

Certain Definitions

        Set forth below is a summary of certain defined terms used in the Indenture. Reference is made to the Indenture for the full definition of all such terms, as well as any other terms used herein for which no definition is provided.

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        "Acquired Indebtedness" means Indebtedness of a Person or any of its Subsidiaries existing at the time such Person becomes a Subsidiary of the Company or at the time it merges or consolidates with the Company or any of its Subsidiaries or assumed in connection with the acquisition of assets from such Person and in each case whether or not incurred by such Person in connection with, or in anticipation or contemplation of, such Person becoming a Subsidiary of the Company or such acquisition, merger or consolidation.

        "Affiliate" means, with respect to any specified Person, any other Person who directly or indirectly through one or more intermediaries, controls, or is controlled by, or is under common control with, such specified Person. The term "control" means the possession, directly or indirectly, of the power to direct or cause the direction of the management and policies of a Person, whether through the ownership of voting securities, by contract or otherwise; and the terms "controlling" and "controlled" have meanings correlative of the foregoing.

        "Asset Acquisition" means: (1) an Investment by the Company or any Subsidiary of the Company in any other Person pursuant to which such Person shall become a Subsidiary of the Company or any Subsidiary of the Company, or shall be merged with or into the Company or any Subsidiary of the Company; or (2) the acquisition by the Company or any Subsidiary of the Company of the assets of any Person (other than a Subsidiary of the Company) that constitute all or substantially all of the assets of such Person or comprises any division or line of business of such Person or any other properties or assets of such Person other than in the ordinary course of business.

        "Asset Sale" means any direct or indirect sale, issuance, conveyance, transfer, lease (other than operating leases entered into in the ordinary course of business), assignment or other transfer for value by us or any of our Subsidiaries (including any sale and leaseback transaction) to any Person other than us or our Wholly Owned Subsidiaries of:

        "Board of Directors" means, as to any Person, the board of directors of such Person or any duly authorized committee thereof.

        "Board Resolution" means, with respect to any Person, a copy of a resolution certified by the Secretary or an Assistant Secretary of such Person to have been duly adopted by the Board of Directors of such Person and to be in full force and effect on the date of such certification, and delivered to the Trustee.

        "Capitalized Lease Obligation" means, as to any Person, the obligations of such Person under a lease that are required to be classified and accounted for as capital lease obligations under GAAP and, for purposes of this definition, the amount of such obligations at any date shall be the capitalized amount of such obligations at such date, determined in accordance with GAAP.

        "Capital Stock" means:

        "Common Stock" of any Person means any and all shares, interests or other participations in, and other equivalents (however designated and whether voting or non-voting) of such Person's common stock, and includes, without limitation, all series and classes of such common stock.

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        "Consolidated EBITDA" means, with respect to any Person, for any period, the sum (without duplication) of:

all as determined on a consolidated basis for such Person and its Subsidiaries in accordance with GAAP.

        "Consolidated Fixed Charge Coverage Ratio" means, with respect to any Person, the ratio of Consolidated EBITDA of such Person during the four full fiscal quarters (the "Four Quarter Period") ending prior to the date of the transaction giving rise to the need to calculate the Consolidated Fixed Charge Coverage Ratio for which financial statements are available (the "Transaction Date") to Consolidated Fixed Charges of such Person for the Four Quarter Period. In addition to and without limitation of the foregoing, for purposes of this definition, "Consolidated EBITDA" and "Consolidated Fixed Charges" shall be calculated after giving effect on a pro forma basis for the period of such calculation to:

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        "Consolidated Fixed Charges" means, with respect to any Person for any period, the sum, without duplication, of:

        "Consolidated Interest Expense" means, with respect to any Person for any period, the sum of, without duplication:

        "Consolidated Net Income" means, with respect to any Person, for any period, the aggregate net income (or loss) of such Person and its Subsidiaries before the payment of dividends on Preferred Stock for such period on a consolidated basis, determined in accordance with GAAP; provided that there shall be excluded therefrom:

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        "Consolidated Net Worth" of any Person means the consolidated stockholders' equity of such Person, as of the end of the last completed fiscal quarter ending on or prior to the date of the transaction giving rise to the need to calculate Consolidated Net Worth determined on a consolidated basis in accordance with GAAP, less (without duplication) amounts attributable to Disqualified Capital Stock of such Person and interests in such Person's Consolidated Subsidiaries not owned, directly or indirectly, by such Person.

        "Consolidated Subsidiary" means, with respect to any Person, a Subsidiary of such Person, the financial statements of which are consolidated with the financial statements of such Person in accordance with GAAP.

        "Currency Agreement" means any foreign exchange contract, currency swap agreement or other similar agreement or arrangement designed to protect the Company or any Subsidiary of the Company against fluctuations in currency values.

        "Default" means an event or condition the occurrence of which is, or with the lapse of time or the giving of notice or both would be, an Event of Default.

        "Disqualified Capital Stock" means that portion of any Capital Stock that, by its terms (or by the terms of any security into which it is convertible or for which it is exchangeable at the option of the holder thereof), or upon the happening of any event, matures or is mandatorily redeemable, pursuant to a sinking fund obligation or otherwise, or is redeemable at the sole option of the holder thereof on or prior to the final maturity date of the Notes.

        "Exchange Act" means the Securities Exchange Act of 1934, as amended, or any successor statute or statutes thereto.

        "Existing Credit Agreements" mean: (1) Revolving Credit Agreement, dated as of April 19, 2004 and as amended as of December 17, 2004 and September 16, 2005, among the Company, the lenders party thereto and JP Morgan Chase Bank, as administrative agent; and (2) the credit facility between Deutsche Bank AG, New York Branch, and iStar DB Seller LLC, dated as of January 11, 2001, in each case together with the related documents thereto (including, without limitation, any security documents), in each case as such agreements may be amended (including any amendment and restatement thereof), supplemented or otherwise modified from time to time, including any agreement extending the maturity of, refinancing, replacing or otherwise restructuring (including increasing the amount of available borrowings thereunder (provided that such increase in borrowings is permitted by the "Limitation on Incurrence of Additional Indebtedness" covenant above) or adding Subsidiaries of the Company as additional borrowers or guarantors thereunder) all or any portion of the Indebtedness under such agreement or any successor or replacement agreement and whether by the same or any other agent, lender or group of lenders.

        "Fair market value" means, with respect to any asset or property, the price which could be negotiated in an arm's-length, free market transaction, for cash, between a willing seller and a willing and able buyer, neither of whom is under undue pressure or compulsion to complete the transaction. Fair market value shall be determined by the Board of Directors of the Company acting reasonably and in good faith and shall be evidenced by a Board Resolution of the Board of Directors of the Company delivered to the Trustee.

        "GAAP" means generally accepted accounting principles set forth in the opinions and pronouncements of the Accounting Principles Board of the American Institute of Certified Public Accountants and statements and pronouncements of the Financial Accounting Standards Board or in such other statements by such other entity as may be approved by a significant segment of the

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accounting profession of the United States. For the avoidance of doubt, revenues, expenses, gains and losses that are included in results of discontinued operations because of the application of SFAS No. 144 will be treated as revenues, expenses, gains and losses from continuing operations.

        "Guarantor" means: each of the Company's Subsidiaries that in the future executes a supplemental indenture in which such Subsidiary agrees to be bound by the terms of the Indenture as a guarantor; provided that any Person constituting a guarantor as described above shall cease to constitute a guarantor when its respective guarantee is released in accordance with the terms of the Indenture.

        "Indebtedness" means with respect to any Person, without duplication:

        For purposes hereof, the "maximum fixed repurchase price" of any Disqualified Capital Stock which does not have a fixed repurchase price shall be calculated in accordance with the terms of such Disqualified Capital Stock as if such Disqualified Capital Stock were purchased on any date on which Indebtedness shall be required to be determined pursuant to the Indenture, and if such price is based upon, or measured by, the fair market value of such Disqualified Capital Stock, such fair market value shall be determined reasonably and in good faith by the Board of Directors of the issuer of such Disqualified Capital Stock.

        "Interest Swap Obligations" means the obligations of any Person pursuant to any arrangement with any other Person, whereby, directly or indirectly, such Person is entitled to receive from time to time periodic payments calculated by applying either a floating or a fixed rate of interest on a stated notional amount in exchange for periodic payments made by such other Person calculated by applying a fixed or a floating rate of interest on the same notional amount and shall include, without limitation, interest rate swaps, caps, floors, collars and similar agreements.

        "Investment" means, with respect to any Person, any direct or indirect loan or other extension of credit (including, without limitation, a guarantee), or corporate tenant lease to or capital contribution

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to (by means of any transfer of cash or other property to others or any payment for property or services for the account or use of others), or any purchase or acquisition by such Person of any Capital Stock, bonds, notes, debentures or other securities or evidences or Indebtedness issued by, any Person. "Investment" shall exclude extensions of trade credit by us and our Subsidiaries on commercially reasonable terms in accordance with our or our Subsidiaries' normal trade practices, as the case may be.

        "Lien" means any lien, mortgage, deed of trust, pledge, security interest, charge or encumbrance of any kind (including any conditional sale or other title retention agreement, any lease in the nature thereof and any agreement to give any security interest).

        "Non-Recourse Indebtedness" means any of our or any of our Subsidiaries' Indebtedness that is:

        "Obligations" means all obligations for principal, premium, interest, penalties, fees, indemnification, reimbursements, damages and other liabilities payable under the documentation governing any Indebtedness.

        "Permitted Indebtedness" means, without duplication, each of the following:

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        For purposes of determining compliance with the "Limitation on Incurrence of Additional Indebtedness" covenant, in the event that an item of Indebtedness meets the criteria of more than one of the categories of Permitted Indebtedness described in clauses (1) through (11) above or is entitled to be incurred pursuant to the second paragraph of such covenant, the Company shall, in its sole discretion, classify (or later reclassify) such item of Indebtedness in any manner that complies with this covenant. Accrual of interest, accretion or amortization of original issue discount, the payment of interest on any Indebtedness in the form of additional Indebtedness with the same terms, and the payment of dividends on Disqualified Capital Stock in the form of additional shares of the same class of Disqualified Capital Stock will not be deemed to be an incurrence of Indebtedness or an issuance of Disqualified Capital Stock for purposes of the "Limitations on Incurrence of Additional Indebtedness" covenant.

        "Person" means an individual, partnership, corporation, unincorporated organization, trust or joint venture, or a governmental agency or political subdivision thereof.

        "Preferred Stock" of any Person means any Capital Stock of such Person that has preferential rights to any other Capital Stock of such Person with respect to dividends or redemptions or upon liquidation.

        "Qualified Capital Stock" means any Capital Stock that is not Disqualified Capital Stock.

        "Refinance" means, in respect of any security or Indebtedness, to refinance, extend, renew, refund, repay, prepay, redeem, defease or retire, or to issue a security or Indebtedness in exchange or replacement for, such security or Indebtedness in whole or in part. "Refinanced" and "Refinancing" shall have correlative meanings.

        "Refinancing Indebtedness" means any Refinancing by the Company or any Subsidiary of the Company of Indebtedness incurred in accordance with the "Limitation on Incurrence of Additional Indebtedness" covenant (other than pursuant to clauses (2), (4), (5), (6), (7), (8), (9) or (11) of the definition of Permitted Indebtedness), in each case that does not:

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        "REIT" means Real Estate Investment Trust.

        "Secured Indebtedness" means any Indebtedness secured by a Lien upon the property of the Company or any of its Subsidiaries.

        "Significant Subsidiary," with respect to any Person, means any Subsidiary of such Person that satisfies the criteria for a "significant subsidiary" set forth in Rule 1.02(w) of Regulation S-X under the Exchange Act.

        "Subsidiary," with respect to any Person, means:

        "Total Unencumbered Assets" as of any date means the sum of:

        "Undepreciated Real Estate Assets" means, as of any date, the cost (being the original cost to the Company or any of Subsidiaries plus capital improvements) of real estate assets of the Company and its Subsidiaries on such date, before depreciation and amortization of such real estate assets, determined on a consolidated basis in accordance with GAAP.

        "Unsecured Indebtedness" means any Indebtedness of the Company or any of its Subsidiaries that is not Secured Indebtedness.

        "Weighted Average Life to Maturity" means, when applied to any Indebtedness at any date, the number of years obtained by dividing: (1) the then outstanding aggregate principal amount of such Indebtedness into; (2) the sum of the total of the products obtained by multiplying (i) the amount of each then remaining installment, sinking fund, serial maturity or other required payment of principal, including payment at final maturity, in respect thereof, by (ii) the number of years (calculated to the nearest one-twelfth) which will elapse between such date and the making of such payment.

        "Wholly Owned Subsidiary" of any Person means any Subsidiary of such Person of which all the outstanding voting securities (other than in the case of a foreign Subsidiary, directors' qualifying shares or an immaterial amount of shares required to be owned by other Persons pursuant to applicable law) are owned by such Person or any Wholly Owned Subsidiary of such Person.

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CERTAIN U.S. FEDERAL INCOME TAX CONSEQUENCES

         The American Jobs Creation Act

        The following discussion should be read together with the discussion under "—Certain Federal Income Tax Consequences—Requirements for Qualification as a Real Estate Investment Trust" in the accompanying prospectus and is subject to the assumptions and limitations therein.

        The American Jobs Creation Act of 2004 (the "Act") was enacted on October 22, 2004. The Act modifies the manner in which we apply the gross income and asset test requirements under the Code. (See the discussion under "—Certain Federal Income Tax Consequences—Requirements for Qualification as a Real Estate Investment Trust" in the accompanying prospectus for a detailed discussion of these rules as applied prior to the Act). With respect to the asset tests, the Act expands the types of securities that qualify as "straight debt" for purposes of 10% value limitation. The Act also clarifies that certain types of debt instruments, including loans to individuals or estates and securities of a REIT, are not "securities" for purposes of the 10% value limitation. With respect to the gross income tests, the Act provides that for our taxable years beginning on or after January 1, 2005, except to the extent provided by Treasury regulations, our income from certain hedging transactions that are clearly identified as hedges under Section 1221 of the Code, including gain from the sale or disposition of such a transaction, will be excluded from gross income for purposes of the 95% gross income test to the extent the transaction hedges any indebtedness incurred or to be incurred by the trust to acquire or carry real estate assets, including real estate mortgage loans.

        The Act also sets forth rules that permit a REIT to avoid disqualification for de minimis failures (as defined in the Act) to satisfy the 5% value and 10% vote and value limitations under the asset tests if the REIT either disposes of the assets within six months after the last day of the quarter in which the REIT identifies the failure (or such other time period prescribed by the Treasury), or otherwise meets the requirements of such asset tests by the end of such time period. In addition, if a REIT fails to meet any of the asset test requirements for a particular quarter, and the de minimis exception described above does not apply, the REIT may cure such failure if the failure was due to reasonable cause and not due to willful neglect, the REIT identifies such failure to the Internal Revenue Service (the "IRS") and disposes of the assets that caused the failure within six months after the last day of the quarter in which the identification occurred, and the REIT pays a tax with respect to the failure equal to the greater of (i) $50,000, or (ii) an amount determined (pursuant to Treasury regulations) by multiplying the highest rate of tax for corporations under Section 11 of the Code, by the net income generated by the assets for the period beginning on the first date of the failure and ending on the date the REIT has disposed of the assets (or otherwise satisfies the requirements). In addition to the foregoing, the Act provides that if we fail to satisfy the 75% gross income test or the 95% gross income test, but nonetheless maintain our qualification as a REIT because other requirements are met, we will be subject to a 100% tax on an amount equal to (1) the greater of (A) the amount by which we fail the 75% gross income test or (B) the amount by which we fail the 95% gross income test, as the case may be, multiplied by (2) a fraction intended to reflect our profitability. Finally, the Act provides that if a REIT fails to satisfy one or more requirements for REIT qualification, other than by reason of a failure to comply with the provisions of the reasonable cause exception to the gross income tests and the provisions described above with respect to failure to comply with the asset tests, the REIT may retain its REIT qualification if the failures are due to reasonable cause and not due to willful neglect, and if the REIT pays a penalty of $50,000 for each such failure. The provisions described in this paragraph will only apply to our taxable years beginning on or after January 1, 2005.

Taxation of Holders of the Notes

        The following discussion is a summary of certain U.S. federal income tax consequences expected to result from the purchase, ownership and disposition of the Notes by holders who acquire the Notes at

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original issuance for the issue price (the first price at which a substantial amount of the Notes are sold to purchasers other than bond houses, brokers or similar persons or organizations acting in the capacity as underwriters, placement agents or wholesalers) and who hold the Notes as "capital assets" (generally, property held for investment) within the meaning of Section 1221 of the Code. This summary is based upon current provisions of the Code, applicable Treasury regulations, judicial authority and administrative rulings and practice, any of which may be altered with retroactive effect thereby changing the U.S. federal income tax consequences discussed below. There can be no assurance that the IRS will not take a contrary view, and no ruling from the IRS has been or is expected to be sought.

        The U.S. federal income tax treatment of a holder of Notes may vary depending upon such holder's particular situation. Certain holders (including, but not limited to, banks, certain financial institutions, persons who mark-to-market the Notes, individuals, partnerships or other passthrough entities, insurance companies, broker-dealers, expatriates and persons holding the Notes as part of a "straddle," "hedge" or "conversion transaction") may be subject to special rules not discussed below.

        PROSPECTIVE INVESTORS SHOULD CONSULT THEIR TAX ADVISORS AS TO THE PARTICULAR TAX CONSEQUENCES TO THEM OF THE PURCHASE, OWNERSHIP AND DISPOSITION OF THE NOTES, INCLUDING THE APPLICABILITY AND EFFECT OF ANY U.S. FEDERAL, STATE, LOCAL, FOREIGN OR OTHER TAX LAWS OR TAX TREATIES.

        As used herein, the term "U.S. Holder" means a beneficial owner of Notes that is for U.S. federal income tax purposes:

        As used herein, the term "Non-U.S. Holder" means a beneficial owner of Notes that is, for U.S. federal income tax purposes, a nonresident alien or a corporation, estate or trust that is not a U.S. Holder.

U.S. Holders

        Payments of Interest.    Interest payments on the Notes will constitute "qualified stated interest." Accordingly, interest on the Notes will be taxable to a U.S. Holder as ordinary income at the time it accrues or is received, in accordance with the U.S. Holder's regular method of accounting for U.S. federal income tax purposes.

        Sale, Retirement or Other Taxable Disposition.    In general, a U.S. Holder of a Note will recognize gain or loss upon the sale, retirement or other taxable disposition of such Note in an amount equal to the difference between:

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        A U.S. Holder's tax basis in a Note generally will be equal to the price paid for such Note. Capital gain recognized by a non-corporate U.S. Holder from the sale of a capital asset that has been held for more than one year generally will be subject to tax at a rate not to exceed 15%, whereas capital gain recognized by a non-corporate U.S. Holder from the sale of a capital asset held for one year or less generally will be subject to tax at ordinary income tax rates. Capital gain recognized by a corporate U.S. Holder will be subject to tax at the ordinary income tax rates applicable to corporations regardless of the corporation's holding period. The deductibility of capital loss is subject to limitations.

Non-U.S. Holders

        A Non-U.S. Holder will not be subject to U.S. federal income or withholding tax on payments of interest on a Note (the "portfolio interest exemption") if such payments are not effectively connected with the conduct of a U.S. trade or business, unless such Non-U.S. Holder (i) owns directly, or by attribution, 10% or more of the total combined voting power of all classes of our stock entitled to vote, (ii) is a controlled foreign corporation related to us, or (iii) is a bank as to which the interest represents interest received on an extension of credit made pursuant to a loan agreement entered into in the ordinary course of its trade or business, in which case such interest will be subject to a 30% withholding tax (unless reduced or eliminated by an applicable treaty). To qualify for the exemption from taxation (or the elimination or reduction of the applicable withholding tax under a treaty), the last United States payor in the chain of payment prior to payment to a Non-U.S. Holder (the "Withholding Agent") must have received, before payment, a statement that

        The statement may be made on an IRS Form W-8BEN (or a substantially similar form), and the Non-U.S. Holder must inform the Withholding Agent of any change in the information on the statement within 30 days of such change. If a Note is held through a securities clearing organization or certain other financial institutions, the beneficial owner of the Note must provide the above statement to such organization or institution and the organization or institution must provide to the Withholding Agent a certificate stating that such organization or institution has been provided with a valid IRS Form W-8BEN (or substantially similar form).

        In addition, a Non-U.S. Holder generally will not be subject to U.S. federal income or withholding tax on any amount which constitutes gain upon sale, retirement or other disposition of a Note, unless the gain is effectively connected with the conduct of a trade or business in the United States by the Non-U.S. Holder or, in the case of a Non-U.S. Holder who is an individual, the Non-U.S. Holder is present in the United States for 183 days or more in the taxable year of the disposition and certain other conditions are met. Certain other exceptions may be applicable, and a Non-U.S. Holder should consult its tax advisor in this regard.

        If interest and other payments received by a Non-U.S. Holder with respect to the Notes (including proceeds from a sale, retirement or other disposition of the Notes) are effectively connected with the conduct by the Non-U.S. Holder of a trade or business within the United States (or the Non-U.S. Holder is otherwise subject to U.S. federal income taxation on a net basis with respect to such holder's ownership of the Notes), such Non-U.S. Holder will generally be subject to the rules described above

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for a U.S. Holder (subject to any modification provided under an applicable income tax treaty). Such Non-U.S. Holder may also be subject to the "branch profits tax" if such holder is a corporation.

Backup Withholding

        Certain non-corporate U.S. Holders may be subject to backup withholding on payments of principal and interest on, and the proceeds of the disposition of, the Notes, if the U.S. Holder:

        In addition, such payments of principal, interest and disposition proceeds to U.S. Holders will generally be subject to information reporting. U.S. Holders should consult their tax advisors regarding their qualification for exemption from backup withholding and the procedure for obtaining such an exemption, if applicable.

        We must report annually to the IRS and to each Non-U.S. Holder any interest on the Notes that is subject to withholding or that is exempt from U.S. withholding tax pursuant to a tax treaty or the portfolio interest exemption. Copies of these information returns may also be made available under the provisions of a specific treaty or agreement to the tax authorities of the country in which the Non-U.S. Holder resides.

        Backup withholding and other information reporting generally will not apply to payments of interest made to a Non-U.S. Holder of a Note who provides a properly completed IRS Form W-8BEN (or substantially similar form) or otherwise establishes an exemption from backup withholding. Payments of principal or the proceeds of a disposition of the Notes by or through a United States office of a broker generally will be subject to backup withholding and information reporting unless the Non-U.S. Holder certifies its status as a Non-U.S. Holder under penalties of perjury (and certain other conditions are met) or otherwise establishes an exemption. Payments of principal or the proceeds of a disposition of the Notes by or through a foreign office of a United States broker or foreign broker with certain relationships to the United States generally will be subject to information reporting, but not backup withholding.

        Any amounts withheld under the backup withholding rules from a payment to a beneficial owner would be allowed as a refund or a credit against such beneficial owner's U.S. federal income tax liability provided the required information is furnished to the IRS.

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UNDERWRITING

        We are offering the Notes described in this prospectus supplement through the underwriters named below. Merrill Lynch, Pierce, Fenner & Smith Incorporated and UBS Securities LLC are the representatives of the underwriters and the joint book-running managers. Subject to the terms and conditions set forth in the underwriting agreement between us and the representatives, the underwriters named below have agreed to purchase from us, severally and not jointly, the principal amounts of Notes set forth opposite their names below at the public offering price less the underwriting discounts and commissions set forth on the cover page of this prospectus supplement:

Underwriters
   Principal Amount of
Fixed Rate Notes
   Principal Amount of
Floating Rate Notes
Merrill Lynch, Pierce, Fenner & Smith
                      Incorporated		   $ 107,000,000   $ 96,000,000
UBS Securities LLC     107,000,000     96,000,000
HSBC Securities (USA) Inc.     12,000,000     11,000,000
RBC Capital Markets Corporation     12,000,000     11,000,000
Scotia Capital (USA) Inc.     12,000,000     11,000,000
   
 
  Total   $ 250,000,000   $ 225,000,000
   
 

        We estimate that our expenses for this offering will be approximately $810,125.

        The underwriting agreement provides that the obligations of the underwriters are subject to certain conditions precedent.

        We have been advised by the underwriters that the underwriters propose to offer the Notes to the public at the public offering price set forth on the cover page of this prospectus supplement. After commencement of the offering, the offering price and other selling terms may be changed by the underwriters.

        The Notes are not listed on any securities exchange. The underwriters have advised us that they will act as market-makers for the Notes. However, the underwriters are not obligated to do so and may discontinue any market-making at any time without notice. No assurance can be given as to the liquidity of the trading market for the Notes.

        Certain of underwriters will make the notes available for distribution on the Internet through a proprietary web site and/or a third-party system operated by MarketAxess Corporation, or MarketAxess, Internet-based communications technology provider. MarketAxess is providing the system as a conduit for communications between such underwriters and their respective customers and is not a party to any transactions. MarketAxess, a registered broker-dealer, will receive compensation from the underwriters based on transactions the underwriters conduct through the system. Such underwriters will make the securities available to their respective customers through the Internet distributions, whether made through a proprietary or third-party system, on the same terms as distributions made through other channels.

        We have agreed to indemnify the underwriters and certain controlling persons against certain liabilities, including liabilities under the Securities Act.

        The underwriters have advised us that, pursuant to Regulation M under the Exchange Act, certain persons participating in the offering may engage in transactions, including overallotment, stabilizing bids, syndicate covering transactions or the imposition of penalty bids, which may have the effect of stabilizing or maintaining the market price of the Notes at a level above that which might otherwise prevail in the open market. Overallotment involves syndicate sales in excess of the offering size, which creates a syndicate short position. A stabilizing bid is a bid for the purchase of Notes on behalf of the

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underwriters for the purpose of fixing or maintaining the price of the Notes. A syndicate covering transaction is the bid for or the purchase of Notes on behalf of the underwriters to reduce a short position incurred by the underwriters in connection with the offering. A penalty bid is an arrangement permitting the underwriters to reclaim the selling concession otherwise accruing to a syndicate member in connection with the offering if the Notes originally sold by such syndicate member are purchased in a syndicate covering transaction and therefore have not been effectively placed by such syndicate member. The underwriters are not obligated to engage in these activities and, if commenced, any of the activities may be discontinued at any time.

        The underwriters have advised us that they do not intend to confirm sales to any account over which any of them exercises discretionary authority.

        The underwriters and their affiliates have from time to time provided, and may in the future provide, investment banking and/or general financing, banking and advisory services to us and our subsidiaries for customary fees. In addition, affiliates of Merrill Lynch, Pierce, Fenner & Smith Incorporated, UBS Securities LLC, HSBC Securities (USA) Inc., RBC Capital Markets Corporation and Scotia Capital (USA) Inc., the underwriters of this offering, are lenders on our unsecured line of credit and, accordingly, may be repaid in whole or in part from proceeds of the offering. See "Use of Proceeds" herein.

        It is expected that delivery of the Notes will be made against payment therefor on or about December 14, 2005 which is the fifth business day following the date of this prospectus supplement. We refer to this settlement cycle as "T+5." Purchasers of Notes should be aware that the ability to settle secondary market trades of the Notes effected on the date of pricing and the succeeding business days may be affected by the T+5 settlement.


LEGAL MATTERS

        The legality of the Notes offered by this prospectus will be passed upon for us by Clifford Chance US LLP, New York, New York. Clifford Chance US LLP will rely upon the opinion of Venable LLP with respect to certain matters of Maryland law. Certain matters will be passed upon for the underwriters by Skadden, Arps, Slate, Meagher & Flom LLP.


EXPERTS

        The financial statements and management's assessment of the effectiveness of internal control over financial reporting (which is included in Management's Report on Internal Control over Financial Reporting) incorporated in this Prospectus by reference to the Annual Report on Form 10-K for the year ended December 31, 2004 have been so incorporated in reliance on the report of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

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PROSPECTUS

        iSTAR FINANCIAL INC.
Common Stock
Preferred Stock
Depositary Shares
Debt Securities
and
Warrants

        We may from time to time offer our common stock, preferred stock (which we may issue in one or more series), depositary shares representing shares of preferred stock, debt securities (which we may issue in one or more series) or warrants entitling the holders to purchase common stock, preferred stock, depositary shares or debt securities, at an aggregate initial offering price which will not exceed $5,000,000,000. We will determine when we sell securities, the amounts of securities we will sell and the prices and other terms on which we will sell them. We may sell securities to or through underwriters, through agents or directly to purchasers.

        We will describe in a prospectus supplement, which we will deliver with this prospectus, the terms of particular securities which we offer in the future. We may describe the terms of those securities in a term sheet which will precede the prospectus supplement.

        In each prospectus supplement we will include the following information:

        NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED THAT THIS PROSPECTUS IS TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

        An investment in these securities entails certain material risks and uncertainties that should be considered. See "Risk Factors" on page 2 of this prospectus.

December 7, 2005


TABLE OF CONTENTS

ABOUT THIS PROSPECTUS   1
FORWARD-LOOKING STATEMENTS   1
iSTAR FINANCIAL INC.   2
RISK FACTORS   2
RATIOS OF EARNINGS TO COMBINED FIXED CHARGES AND PREFERRED STOCK DIVIDENDS AND EARNINGS TO FIXED CHARGES   9
USE OF PROCEEDS   9
DESCRIPTION OF DEBT SECURITIES   10
DESCRIPTION OF WARRANTS   12
DESCRIPTION OF COMMON STOCK AND PREFERRED STOCK   13
DESCRIPTION OF DEPOSITARY SHARES   18
CERTAIN U.S. FEDERAL INCOME TAX CONSEQUENCES   19
PLAN OF DISTRIBUTION   36
LEGAL MATTERS   37
EXPERTS   37
INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE   38
INFORMATION WE FILE   38

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ABOUT THIS PROSPECTUS

        This prospectus is part of a shelf registration statement. Under this shelf registration statement, we may sell any combination of common stock, preferred stock, depositary shares representing shares of preferred stock, debt securities or warrants entitling the holders to purchase common stock, preferred stock, depositary shares or debt securities in one or more offerings for total proceeds of up to $5,000,000,000. This prospectus provides you with a general description of the securities we may offer. Each time we sell securities, we will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement may add, update or change information contained in this prospectus. Before you buy any of our securities, it is important for you to consider the information contained in this prospectus and any prospectus supplement together with additional information described under the heading "Incorporation of Certain Documents By Reference."


FORWARD-LOOKING STATEMENTS

        We make statements in this prospectus and the documents we incorporate by reference that are considered "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, which are usually identified by the use of words such as "will," "anticipates," "believes," "estimates," "expects," "projects," "plans," "intends," "should" or similar expressions. We intend those forward-looking statements to be covered by the safe harbor provisions for forward-looking statements contained in the Private Securities Reform Act of 1995 and are including this statement for purposes of complying with these safe harbor provisions. These forward-looking statements reflect our current views about our plans, strategies and prospects, which are based on the information currently available to us and on assumptions we have made. Although we believe that our plans, intentions and expectations as reflected in or suggested by those forward-looking statements are reasonable, we can give no assurance that the plans, intentions or expectations will be achieved. We have listed below and have discussed elsewhere in this prospectus some important risks, uncertainties and contingencies which could cause our actual results, performances or achievements to be materially different from the forward-looking statements we make in this prospectus. These risks, uncertainties and contingencies include, but are not limited to, the following:

        We assume no obligation to update publicly any forward-looking statements, whether as a result of new information, future events or otherwise. In evaluating forward-looking statements, you should consider these risks and uncertainties, together with the other risks described from time to time in our reports and documents filed with the SEC, and you should not place undue reliance on those statements.


iSTAR FINANCIAL INC.

        We are the leading publicly-traded finance company focused on the commercial real estate industry. We provide custom-tailored financing to high-end private and corporate owners of real estate, including senior and junior mortgage debt, senior and mezzanine corporate capital and corporate net lease financing. Our objective is to generate consistent and attractive returns on our invested capital by providing innovative and value-added financing solutions to our customers. We are taxed as a REIT.

        Our principal executive offices are located at 1114 Avenue of the Americas, New York, New York 10036, and our telephone number is (212) 930-9400. Our website is www.istarfinancial.com. The information on our website is not considered part of this prospectus. Our five primary regional offices are located in Atlanta, Boston, Dallas, Hartford and San Francisco. iStar Asset Services, our loan servicing subsidiary, is located in Hartford, and iStar Real Estate Services, our corporate facilities management division, is headquartered in Atlanta.


RISK FACTORS

        This section describes material risks of purchasing our securities. You should carefully consider these risks, in addition to the other information contained in this prospectus or incorporated in this prospectus by reference, before purchasing any of the securities offered by this prospectus. In connection with the forward-looking statements that appear in this prospectus, you should carefully review the factors discussed below and the cautionary statements referred to in "Forward-Looking Statements."

We Are Subject to Risks Relating to Our Lending Business.

We may suffer a loss if a borrower defaults on a non-recourse loan or on a loan that is not secured by underlying real estate.

        In the event of a default by a borrower on a non-recourse loan, we will only have recourse to the real estate assets collateralizing the loan. For this purpose, we consider loans made to special purpose entities formed solely for the purpose of holding and financing particular assets to be non-recourse loans. If the underlying asset value is below the loan amount, we will suffer a loss. Conversely, we sometimes make loan investments that are unsecured or are secured by equity interests in the borrowing entities. These loans are subject to the risk that other lenders may be directly secured by the real estate assets of the borrower. In the event of a default, those collateralized lenders would have priority over us with respect to the proceeds of a sale of the underlying real estate.

        In the cases described above, we may lack control over the underlying asset collateralizing our loan or the underlying assets of the borrower prior to a default, and, as a result, their value may be reduced by acts or omissions by owners or managers of the assets. As of September 30, 2005, 86.6% of our loans were non-recourse, based upon the gross carrying value of our loan assets, and 12.3% of our total investments, based on gross carrying value of our total investments, consisted of loans that are unsecured or secured by equity interests in the borrowing entity.

We may suffer a loss in the event of a default or bankruptcy of a borrower, particularly in cases where the borrower has incurred debt that is senior to our loan.

        If a borrower defaults on our loan but does not have sufficient assets to satisfy our loan, we may suffer a loss of principal or interest. In the event of a borrower bankruptcy, we may not have full recourse to the assets of the borrower, or the assets of the borrower may not be sufficient to satisfy our loan. In addition, certain of our loans are subordinate to other debt of the borrower. If a borrower defaults on our loan or on debt senior to our loan, or in the event of a borrower bankruptcy, our loan will be satisfied only after the senior debt. Where debt senior to our loans exists, the presence of intercreditor arrangements may limit our ability to amend our loan documents, assign our loans, accept prepayments, exercise our remedies (through "standstill" periods) and control decisions made in bankruptcy proceedings relating to borrowers. Bankruptcy and borrower litigation can significantly increase the time needed for us to acquire underlying collateral in the event of a default, during which

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time the collateral may decline in value. In addition, there are significant costs and delays associated with the foreclosure process.

We are subject to the risk that provisions of our loan agreements may be unenforceable.

        Our rights and obligations with respect to our loans are governed by written loan agreements and related documentation. It is possible that a court could determine that one or more provisions of a loan agreement are unenforceable, such as a loan prepayment provision or the provisions governing our security interest in the underlying collateral. If this were to happen with respect to a material asset or group of assets, we could be adversely affected.

We are subject to the risks associated with loan participations, such as less than full control rights.

        Some of our assets are participating interests in loans in which we share the rights, obligations and benefits of the loan with other participating lenders. We may need the consent of these parties to exercise our rights under such loans, including rights with respect to amendment of loan documentation, enforcement proceedings in the event of a default and the institution of, and control over, foreclosure proceedings. Similarly, a majority of the participants may be able to take actions to which we object but to which we will be bound if our participation interest represents a minority interest. We may be adversely affected by this lack of full control.

We Are Subject to Risks Relating to Our Corporate Tenant Lease Business.

Lease expirations, lease defaults and lease terminations may adversely affect our revenue.

        Lease expirations, lease defaults and lease terminations may result in reduced revenues if the lease payments received from replacement corporate tenants are less than the lease payments received from the expiring, defaulting or terminating corporate tenants. In addition, lease defaults by one or more significant corporate tenants, lease terminations by corporate tenants following events of casualty or takings by eminent domain, or the failure of corporate tenants under expiring leases to elect to renew their leases, could cause us to experience long periods with no revenue from a facility and to incur substantial capital expenditures in order to obtain replacement corporate tenants.

        As of September 30, 2005, 10.8% of our annualized revenues for the quarter ended September 30, 2005 were derived from our five largest corporate tenant customers. As of September 30, 2005, the percentage of our revenues (based on total revenues for the quarter ended September 30, 2005, annualized) that are subject to expiring leases during each year from 2005 through 2009 is as follows:

2005   0.1%
2006   2.3%
2007   1.5%
2008   1.1%
2009   0.9%

We may need to make significant capital improvements to our corporate facilities in order to remain competitive.

        Our corporate facilities may face competition from newer, more updated facilities. In order to remain competitive, we may need to make significant capital improvements to our existing corporate facilities. In addition, in the event we need to re-lease a corporate facility, we may need to make significant tenant improvements, including conversions of single tenant buildings to multi-tenant buildings. The costs of these improvements could adversely affect our financial performance.

Our ownership interests in corporate facilities are illiquid, hindering our ability to mitigate a loss.

        Since our ownership interests in corporate facilities are illiquid, we may lack the necessary flexibility to vary our investment strategy promptly to respond to changes in market conditions. In

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addition, if we have to foreclose on an asset or if we desire to sell it in an effort to recover or mitigate a loss, we may be unable to do so at all, or only at a discount.

We Are Subject to Risks Relating to Our Asset Concentration.

        As of September 30, 2005, the average size of our lending investments was $28.8 million and the average size of our leasing investments was $25.4 million. No single investment represents more than 3.2% of our annualized revenues for the fiscal quarter ended September 30, 2005. While our asset base is diversified by product line, asset type, obligor, property type and geographic location, it is possible that if we suffer losses on a portion of our larger assets, our financial performance could be adversely impacted.

Recent Strategic Investments Involve Risks.

        We have recently announced strategic investments in complementary businesses and expect that we may announce additional investments from time to time in the future. Strategic investments may involve the incurrence of additional debt and contingent liabilities. In addition, we may incur expenses from these investments, or they may require substantial investments of additional capital, before they begin generating anticipated returns. Strategic transactions involve risks, including:

        These factors could adversely affect our results of operations, liquidity or stock price.

Because We Must Distribute a Portion of Our Income, We Will Continue to Need Additional Debt and/or Equity Capital to Grow.

        We generally must distribute at least 90% of our net taxable income to our stockholders to maintain our REIT status. As a result, those earnings will not be available to fund investment activities. We have historically funded our investments by borrowing from financial institutions and raising capital in the public and private capital markets. We expect to continue to fund our investments this way. If we fail to obtain funds from these sources, it could limit our ability to grow, which could have a material adverse effect on the value of our common stock. Our taxable income has historically been lower than the cash flow generated by our business activities, primarily because our taxable income is reduced by non-cash expenses, such as depreciation and amortization. As a result, our dividend payout ratio as a percentage of free cash flow has generally been lower than our payout ratio as a percentage of net taxable income.

Our Growth Is Dependent on Leverage, Which May Create Other Risks.

        Our success is dependent, in part, upon our ability to grow our assets through the use of leverage. Our ability to obtain the leverage necessary for execution of our business plan will ultimately depend upon our ability to maintain interest coverage ratios meeting market underwriting standards that will vary according to lenders' assessments of our creditworthiness and the terms of the borrowings. As of September 30, 2005, our debt-to-book equity plus accumulated depreciation and loan loss reserves ratio was 1.8x and our total debt obligations outstanding were approximately $5.2 billion. Our charter does not limit the amount of indebtedness which we may incur. Our Board of Directors has overall responsibility for our financing strategy. Stockholder approval is not required for changes to our financing strategy. If our Board of Directors decided to increase our leverage, it could lead to reduced or negative cash flow and reduced liquidity.

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        The percentage of leverage used will vary depending on our estimate of the stability of iStar Financial's cash flow. To the extent that changes in market conditions cause the cost of such financing to increase relative to the income that can be derived from the assets originated, we may reduce the amount of our leverage.

        Leverage creates an opportunity for increased net income, but at the same time creates risks. For example, leveraging magnifies changes in our net worth. We will incur leverage only when there is an expectation that it will enhance returns, although there can be no assurance that our use of leverage will prove to be beneficial. Moreover, there can be no assurance that we will be able to meet our debt service obligations and, to the extent that we cannot, we risk the loss of some or all of our assets or a financial loss if we are required to liquidate assets at a commercially inopportune time.

        We and our subsidiaries are parties to agreements and debt instruments that restrict future indebtedness and the payment of dividends, including indirect restrictions (through, for example, covenants requiring the maintenance of specified levels of net worth and earnings to debt service ratios) and direct restrictions. As a result, in the event of a deterioration in our financial condition, these agreements or debt instruments could restrict our ability to pay dividends. Moreover, if we fail to pay dividends as required by the Internal Revenue Code of 1986, as amended ("Internal Revenue Code") whether as a result of restrictive covenants in our debt instruments or otherwise, we may lose our qualification as a REIT. For more information regarding the consequences of loss of REIT qualification, please read the risk factor entitled "We May Be Subject to Adverse Consequences if We Fail to Qualify as a REIT."

We Utilize Interest Rate Hedging Arrangements Which May Adversely Affect Our Borrowing Cost and Expose Us to Other Risks.

        We have variable rate lending assets and variable rate debt obligations. These assets and liabilities create a natural hedge against changes in variable interest rates. This means that as interest rates increase, we earn more on our variable rate lending assets and pay more on our variable rate debt obligations and, conversely, as interest rates decrease, we earn less on our variable rate lending assets and pay less on our variable rate debt obligations. When our variable rate debt obligations exceed our variable rate lending assets, we utilize derivative instruments to limit the impact of changing interest rates on our net income. We do not use derivative instruments to hedge assets or for speculative purposes. The derivative instruments we use are typically in the form of interest rate swaps and interest rate caps. Interest rate swaps effectively change variable rate debt obligations to fixed rate debt obligations. Interest rate caps effectively limit the maximum interest rate on variable rate debt obligations.

        The primary risks from our use of derivative instruments is the risk that a counterparty to a hedging arrangement could default on its obligation and the risk that we may have to pay certain costs, such as transaction fees or breakage costs, if a hedging arrangement is terminated by us. As a matter of policy, we enter into hedging arrangements with counterparties that are large, creditworthy financial institutions typically rated at least "A/A2" by Standard & Poor's and Moody's Investors Service, respectively. Our hedging strategy is monitored by our Audit Committee on behalf of our Board of Directors and may be changed by the Board of Directors without stockholder approval.

        Developing an effective strategy for dealing with movements in interest rates is complex and no strategy can completely insulate us from risks associated with such fluctuations. There can be no assurance that our hedging activities will have the desired beneficial impact on our results of operations or financial condition.

We Face a Risk of Liability Under Environmental Laws.

        Under various U.S. federal, state and local environmental laws, ordinances and regulations, a current or previous owner of real estate (including, in certain circumstances, a secured lender that

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succeeds to ownership or control of a property) may become liable for the costs of removal or remediation of certain hazardous or toxic substances at, on, under or in its property. Those laws typically impose cleanup responsibility and liability without regard to whether the owner or control party knew of or was responsible for the release or presence of such hazardous or toxic substances. The costs of investigation, remediation or removal of those substances may be substantial. The owner or control party of a site may be subject to common law claims by third parties based on damages and costs resulting from environmental contamination emanating from a site. Certain environmental laws also impose liability in connection with the handling of or exposure to asbestos-containing materials, pursuant to which third parties may seek recovery from owners of real properties for personal injuries associated with asbestos-containing materials. Absent succeeding to ownership or control of real property, a secured lender is not likely to be subject to any of these forms of environmental liability.

Certain Provisions in Our Charter May Inhibit a Change in Control.

        Generally, to maintain our qualification as a REIT under the Internal Revenue Code, not more than 50% in value of our outstanding shares of stock may be owned, directly or indirectly, by five or fewer individuals at any time during the last half of our taxable year. The Internal Revenue Code defines "individuals" for purposes of the requirement described in the preceding sentence to include some types of entities. Under our charter, no person may own more than 9.8% of our outstanding shares of stock, with some exceptions. The restrictions on transferability and ownership may delay, deter or prevent a change in control or other transaction that might involve a premium price or otherwise be in the best interest of the securityholders.

        Our charter authorizes our Board of Directors:

Adverse Changes in General Economic Conditions Can Adversely Affect Our Business.

        Our success is dependent upon the general economic conditions in the geographic areas in which a substantial number of our investments are located. Adverse changes in national economic conditions or in the economic conditions of the regions in which we conduct substantial business likely would have an adverse effect on real estate values and, accordingly, our business.

We May Be Subject to Adverse Consequences If We Fail to Qualify as a REIT.

        We intend to operate so as to qualify as a REIT for U.S. federal income tax purposes. We have received an opinion of our legal counsel, Clifford Chance US LLP, that, based on the assumptions and representations described in "Certain U.S. Federal Income Tax Consequences," our existing legal organization and our actual and proposed method of operation, enable us to satisfy the requirements for qualification as a REIT under the Internal Revenue Code. Investors should be aware, however, that opinions of counsel are not binding on the Internal Revenue Service or any court. The opinion only represents the view of our counsel based on their review and analysis of existing law, some aspects of which include no controlling precedents. Furthermore, both the validity of the opinion and our qualification as a REIT will depend on our continuing ability to meet various requirements concerning, among other things, the ownership of our outstanding stock, the nature of our assets, the sources of our income and the amount of our distributions to our stockholders. See "Certain U.S. Federal Income Tax Consequences—Taxation of iStar Financial—General."

        If we were to fail to qualify as a REIT for any taxable year, we would not be allowed a deduction for distributions to our stockholders in computing our taxable income and we would be subject to

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U.S. federal income tax, including any applicable minimum tax, on our taxable income with respect to any such taxable year at regular corporate rates. Unless entitled to relief under certain Internal Revenue Code provisions, we also would be disqualified from treatment as a REIT for the four subsequent taxable years following the year during which qualification was lost. As a result, cash available for distribution would be reduced for each of the years involved. Furthermore, it is possible that future economic, market, legal, tax or other considerations may cause the Board of Directors to revoke our REIT election. See "Certain U.S. Federal Income Tax Consequences."

To Qualify as a REIT, We May Be Forced to Borrow Funds During Unfavorable Market Conditions.

        To qualify as a REIT, we generally must distribute to our stockholders at least 90% of our net income each year, excluding net capital gains, and we will be subject to regular U.S. federal corporate income taxes to the extent that we distribute less than 100% of our net taxable income each year. In addition, we will be subject to a 4% nondeductible excise tax on the amount, if any, by which distributions paid by us in any calendar year are less than the sum of 85% of our ordinary income, 95% of our capital gain net income and 100% of our undistributed income from prior years. In order to qualify as a REIT and avoid the payment of income and excise taxes, we may need to borrow funds on a short-term, or possibly long-term, basis to meet the REIT distribution requirements even if the prevailing market conditions are not favorable for these borrowings. These borrowing needs could result from, among other things, a difference in timing between the actual receipt of cash and inclusion of income for U.S. federal income tax purposes, the effect of non-deductible capital expenditures, the creation of reserves or required debt or amortization payments.

Dividends Payable by REITs Do Not Qualify for Reduced Tax Rates.

        The maximum U.S. federal income tax rate for dividends payable by domestic corporations to individual U.S. stockholders (as such term is defined under "Certain U.S. Federal Income Tax Consequences" below) is 15% through 2008. Dividends payable by REITs, however, are generally not eligible for the reduced rates. As a result, the more favorable rates applicable to regular corporate dividends could cause stockholders who are individuals to perceive investments in REITs to be relatively less attractive than investments in the stocks of non-REIT corporations that pay dividends, which could adversely affect the value of the stock of REITs, including our common stock.

Possible Legislative or Other Actions Affecting REITs Could Adversely Affect Our Stockholders.

        The rules dealing with U.S. federal income taxation are constantly under review by persons involved in the legislative process and by the Internal Revenue Service and the U.S. Treasury Department. Changes to tax laws (which changes may have retroactive application) could adversely affect our stockholders or us. It cannot be predicted whether, when, in what forms, or with what effective dates, the tax laws applicable to our stockholders or us will be changed.

We Will Pay Some Taxes.

        Even if we qualify as a REIT for U.S. federal income tax purposes, we will be required to pay some U.S. federal, state, local, and foreign taxes on our income and property. In addition, our "taxable REIT subsidiaries" are fully taxable corporations, and there are limitations on the ability of taxable REIT subsidiaries to make interest payments to affiliated REITs. In addition, we will be subject to a 100% penalty tax to the extent economic arrangements among our tenants, our taxable REIT subsidiary and us are not comparable to similar arrangements among unrelated parties. We will also be subject to a 100% tax to the extent we derive income from the sale of assets to customers in the ordinary course of business. To the extent that we or our taxable REIT subsidiary are required to pay U.S. federal, state, local or foreign taxes, we will have less cash available for distribution to stockholders.

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Certain Financing Activities May Subject Us to U.S. Federal Income Tax and Increase the Tax Liability of Our Stockholders.

        Although we do not intend to invest a material portion of our assets in real estate mortgage investment conduits, or "REMICs," certain taxable income produced by REMIC residual interests may cause our stockholders to suffer adverse tax consequences. In addition, we have entered into certain financing transactions which are treated as taxable mortgage pools, and with respect to which we are treated as owning residual interests.

        Although the law on the matter is unclear, we might be taxable at the highest corporate income tax rate on a portion of the income arising from a taxable mortgage pool that is allocable to the percentage of our shares held by "disqualified organizations," which are generally certain cooperatives, governmental entities and tax-exempt organizations that are exempt from unrelated business taxable income. We believe that disqualified organizations own our shares. Because this tax would be imposed on us, all of our investors, including investors that are not disqualified organizations, would bear a portion of the tax cost associated with the classification of us or a portion of our assets as a taxable mortgage pool. In addition, if we realize "excess inclusion income" and allocate it to stockholders, this income cannot be offset by net operating losses of our stockholders. In addition, if the stockholder is a tax-exempt entity and not a disqualified organization, then the excess inclusion income would be fully taxable as unrelated business taxable income under Section 512 of the Internal Revenue Code. If the stockholder is a foreign person, it would be subject to U.S. federal income tax withholding on the excess inclusion income and would not be able to reduce such withholding tax pursuant to any otherwise applicable income tax treaty. See "Certain U.S. Federal Income Tax Consequences—Effect of Subsidiary Entities—Taxable Mortgage Pools," and "—Excess Inclusion Income."

Our Board of Directors May Change Certain of Our Policies Without Stockholder Approval.

        Our charter provides that our primary purpose is to invest in a diversified portfolio of debt and debt-like interests in real estate and real estate related assets, although it does not set forth specific percentages of the types of investments we may make. Our Board of Directors determines our investment policies, as well as our financing and conflicts of interest policies. Although the Board of Directors has no present intention to do so, it can amend, revise or eliminate these policies at any time and from time to time at its discretion without a vote of the stockholders. A change in these policies could adversely affect our financial condition or results of operations or the market price of our common stock.

A Portion of The Dividends We Distribute May Be Deemed a Return of Capital For U.S. Federal Income Tax Purposes.

        The amount of dividends we distribute to our common stockholders in a given quarter may not correspond to our taxable income for such quarter. Consequently, a portion of the dividends we distribute may be deemed a return of capital for U.S. federal income tax purposes, and will not be taxable but will reduce stockholders' basis in its common stock. For the year ended December 31, 2004, the percentage of our dividend payments made to common stockholders that was treated as a return of capital was 41.2%.

Quarterly Results May Fluctuate and May Not Be Indicative of Future Quarterly Performance.

        Our quarterly operating results could fluctuate; therefore, you should not rely on past quarterly results to be indicative of our performance in future quarters. Factors that could cause quarterly operating results to fluctuate include, among others, variations in our investment origination volume, variations in the timing of prepayments, the degree to which we encounter competition in our markets and general economic conditions.

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RATIOS OF EARNINGS TO COMBINED FIXED CHARGES AND
PREFERRED STOCK DIVIDENDS AND EARNINGS TO FIXED CHARGES

 
    
   Years Ended December 31,
 
   Nine Months Ended
September 30, 2005
 
   2004
   2003
   2002
   2001
   2000
Ratio of earnings to combined fixed charges and preferred stock dividends(1)   1.7x (2) 1.5x (3) 2.0x   1.7x   1.8x   1.7x
Ratio of earnings to fixed charges(1)   1.9x (2) 1.8x (3) 2.4x   2.1x   2.2x   2.1x
(1)
For the purposes of calculating the ratio of earnings to fixed charges, "earnings" consist of income from continuing operations before adjustment for minority interest in consolidated subsidiaries, or income or loss from equity investees, income taxes and cumulative effect of change in accounting principle plus "fixed charges" and certain other adjustments. "Fixed charges" consist of interest incurred on all indebtedness (including amortization of original issue discount) and the implied interest component of our rent obligations in the years presented.

(2)
Includes the effect of STARs asset-backed notes redemption charge of $44.3 million. Excluding this charge, the ratio of earnings to fixed charges and preferred stock dividends and the ratio of earnings to fixed charges would have been 1.8x and 2.1x respectively.

(3)
Includes the effect of chief executive officer, chief financial officer and ACRE Partners compensation charges of $106.9 million, 8.75% Senior Notes due 2008 redemption charge of $11.5 million and, for the ratio of earnings to combined fixed charges and preferred dividends, preferred stock redemption charge of $9.0 million. Excluding these charges, the ratio of earnings to combined fixed charges and preferred stock dividends and the ratio of earnings to fixed changes would have been 2.0x and 2.3x respectively.


USE OF PROCEEDS

        Except as may be set forth in a particular prospectus supplement, we will add the net proceeds from sales of securities to our general corporate funds, which we may use to repay indebtedness, for new investments, or for other general corporate purposes.

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DESCRIPTION OF DEBT SECURITIES

        We will issue the debt securities under an indenture dated as of February 5, 2001 with US Bank Trust National Association, as trustee, which we may supplement from time to time. The following paragraphs describe the provisions of the indenture. We have filed the indenture as an exhibit to the registration statement of which this prospectus is a part and you may inspect it at the office of the trustee.

General

        The debt securities will be our direct, unsecured obligations and may be either senior debt securities or subordinated debt securities. The indenture does not limit the principal amount of debt securities that we may issue. We may issue debt securities in one or more series. A supplemental indenture will set forth specific terms of each series of debt securities. There will be prospectus supplements relating to particular series of debt securities. Each prospectus supplement will describe:

        The indenture does not contain any restrictions on the payment of dividends or the repurchase of our securities or any financial covenants. However, supplemental indentures relating to particular series of debt securities may contain provisions of that type.

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        We may issue debt securities at a discount from their stated principal amount. A prospectus supplement may describe U.S. federal income tax considerations and other special considerations applicable to a debt security issued with original issue discount.

        If the principal of, premium, if any, or interest with regard to any series of debt securities is payable in a foreign currency, we will describe in the prospectus supplement relating to those debt securities any restrictions on currency conversions, tax considerations or other material restrictions with respect to that issue of debt securities.

Form of Debt Securities

        We may issue debt securities in certificated or uncertificated form, in registered form with or without coupons or in bearer form with coupons, if applicable.

        We may issue debt securities of a series in the form of one or more global certificates evidencing all or a portion of the aggregate principal amount of the debt securities of that series. We may deposit the global certificates with depositaries, and the certificates may be subject to restrictions upon transfer or upon exchange for debt securities in individually certificated form.

Events of Default and Remedies

        An event of default with respect to each series of debt securities will include:

        Supplemental indentures relating to particular series of debt securities may include other events of default.

        The indenture provides that the trustee may withhold notice to the holders of any series of debt securities of any default (except a default in payment of principal, premium, if any, or interest, if any) if the trustee considers it in the interest of the holders of the series to do so.

        The indenture provides that if any event of default has occurred and is continuing, the trustee or the holders of not less than 25% in principal amount of a series of debt securities then outstanding may declare the principal of and accrued interest, if any, on that series of debt securities to be due and payable immediately. However, if we cure all defaults (except the failure to pay principal, premium or interest which became due solely because of the acceleration) and certain other conditions are met, that declaration may be annulled and past defaults may be waived by the holders of a majority in principal amount of the applicable series of debt securities.

        The holders of a majority of the outstanding principal amount of a series of debt securities will have the right to direct the time, method and place of conducting proceedings for any remedy available to the trustee, subject to certain limitations specified in the indenture.

        A prospectus supplement will describe any additional or different events of default which apply to any series of debt securities.

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Modification of the Indenture

        We and the trustee may:

        However, we may not:

Mergers and Other Transactions

        We may not consolidate with or merge into any other entity, or transfer or lease our properties and assets substantially as an entirety to another person, unless: (1) the entity formed by the consolidation or into which we are merged, or which acquires or leases our properties and assets substantially as an entirety, assumes by a supplemental indenture all our obligations with regard to outstanding debt securities and our other covenants under the indenture; and (2) with regard to each series of debt securities, immediately after giving effect to the transaction, no event of default, with respect to that series of debt securities, and no event which would become an event of default, will have occurred and be continuing.

Governing Law

        The indenture, each supplemental indenture, and the debt securities issued under them will be governed by, and construed in accordance with, the laws of New York.


DESCRIPTION OF WARRANTS

        Each issue of warrants will be the subject of a warrant agreement which will contain the terms of the warrants. We will distribute a prospectus supplement with regard to each issue of warrants. Each prospectus supplement will describe, as to the warrants to which it relates:

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DESCRIPTION OF COMMON STOCK AND PREFERRED STOCK

        Our authorized capital stock consists of 200,000,000 shares of common stock, $0.001 par value, 45,000 shares of High Performance Common Stock and 30,000,000 shares of preferred stock, $0.001 par value, of which 4,600,000 shares are designated 8.000% Series D Cumulative Redeemable Preferred Stock, $0.001 par value, 9,000,000 shares are designated 7.875% Series E Cumulative Redeemable Preferred Stock, $0.001 par value, 4,600,000 shares are designated 7.800% Series F Cumulative Redeemable Preferred Stock, $0.001 par value, 3,200,000 shares are designated 7.650% Series G Cumulative Redeemable Preferred Stock, $0.001 par value and 5,000,000 shares are designated 7.500% Series I Cumulative Redeemable Preferred Stock, $0.001 par value. At September 30, 2005, 113,095,600 shares of common stock, 41,475 shares of High Performance Common Stock, 4,000,000 shares of Series D preferred stock, 5,600,000 shares of Series E preferred Stock, 4,000,000 shares of Series F preferred stock, 3,200,000 shares of Series G preferred stock and 5,000,000 shares of our Series I preferred stock were outstanding. We previously had authorized and issued series of preferred stock designated Series A, B, C, and H preferred stock; however, we have retired each of those series, which makes the shares available for re-issuance and re-designation.

Common Stock

        Holders of common stock will be entitled to receive distributions on common stock if, as and when the Board of Directors authorizes and declares distributions. However, rights to distributions may be subordinated to the rights of holders of preferred stock, when preferred stock is issued and outstanding. In the event of our liquidation, dissolution or winding up, each outstanding share of common stock will entitle its holder to a proportionate share of the assets that remain after we pay our liabilities and any preferential distributions owed to preferred stockholders.

        Holders of the common stock are entitled to one vote for each share on all matters submitted to a stockholder vote. Holders of the Series D preferred stock are entitled to 0.25 of a vote for each share on all matters submitted to a stockholder vote. They will vote with the common stock as a single class. There is no cumulative voting in the election of directors.

        Holders of shares of common stock have no preference, conversion, sinking fund, redemption, appraisal or exchange rights or any preemptive rights to subscribe for any of our securities. All shares of common stock have equal dividend, distribution, liquidation and other rights.

        We may be dissolved if the Board of Directors, by resolution adopted by a majority of the entire Board of Directors, declares the dissolution advisable and directs that the proposed dissolution be submitted for consideration at either an annual or special meeting of stockholders. Dissolution will occur once it is approved by the affirmative vote of a majority of stockholders entitled to cast votes on the matter.

        Our charter grants the Board of Directors the power to authorize the issuance of additional authorized but unissued shares of common stock and preferred stock. The Board of Directors may also classify or reclassify unissued shares of common stock or preferred stock and authorize their issuance.

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        Our charter also provides that, to the extent permitted by the General Corporate Law of Maryland, the Board of Directors may, without any action by the stockholders, amend our charter from time to time to increase or decrease the aggregate number of shares of stock or the number of shares of stock of any class or series that we have authority to issue.

        We believe that these powers of the Board of Directors provide increased flexibility in structuring possible future financings and acquisitions and in meeting other needs which might arise. Although the Board of Directors does not intend to do so at the present time, it could authorize the issuance of a class or series that could delay, defer or prevent a change of control or other transaction that might involve a premium price for the common stock or otherwise be in the best interest of the stockholders.

High Performance Unit Program

        In May 2002 and June 2003, the Company's stockholders initially approved two iStar Financial High Performance Unit Programs. The programs, as more fully described in the Company's annual proxy statements dated April 8, 2002, April 21, 2003, April 27, 2004 and April 25, 2005 are performance-based employee, director and officer compensation plans that only have material value to the participants if the Company provides superior returns to its stockholders. The programs entitle the employee, director and officer participants to receive cash distributions in the nature of common stock dividends if the total rate of return on the Company's Common Stock (share price appreciation plus dividends) exceeds certain performance levels.

        Initially, there were three plans within the employee program: the 2002 plan, the 2003 plan, and the 2004 plan. Each plan has 5,000 shares of High Performance Common Stock associated with it. Each share of High Performance Common Stock carries 0.25 votes per share.

        For these three plans, the Company's performance is measured over a one-, two-, or three-year valuation period, beginning on January 1, 2002 and ending on December 31, 2002, December 31, 2003 and December 31, 2004, respectively. The end of the valuation period (i.e., the "valuation date") will be accelerated if there is a change in control of the Company. The High Performance Common Stock has a nominal value unless the total rate of stockholder return for the relevant valuation period exceeds the greater of: (1) 10.00%, 20.00%, or 30.00% for the 2002 plan, the 2003 plan and the 2004 plan, respectively; and (2) a weighted industry index total rate of return consisting of equal weightings of the Russell 1000 Financial Index and the Morgan Stanley REIT Index for the relevant period.

        If the total rate of return on the Company's Common Stock exceeds the threshold performance levels for a particular plan, then distributions will be paid on the shares of High Performance Common Stock related to that plan in the same amounts and at the same times as distributions are paid on a number of shares of the Company's Common Stock equal to the following: 7.50% of the Company's excess total rate of return (over the higher of the two threshold performance levels) multiplied by the weighted average market value of the Company's common equity capitalization during the measurement period, all as divided by the average closing price of a share of the Company's Common Stock for the 20 trading days immediately preceding the applicable valuation date.

        If the total rate of return on the Company's Common Stock does not exceed the threshold performance levels for a particular plan, then the shares of High Performance Common Stock related to that plan will have only nominal value. In this event, each of the 5,000 shares will be entitled to dividends equal to 0.01 times the dividend paid on a share of Common Stock, if and when dividends are declared on the common stock.

        Regardless of how much the Company's total rate of return exceeds the threshold performance levels, the dilutive impact to the Company's stockholders resulting from distributions on High Performance Common Stock in each plan is limited to 1.00% of the number of shares of the Company's Common Stock outstanding, on a fully diluted basis, on the valuation date for each plan.

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        A new 2005 plan was then established with a three-year period ending December 31, 2005. Awards under the 2005 plan were approved on January 14, 2003. The 2005 plan also has 5,000 shares of High Performance Common Stock with an aggregate initial purchase price of $573,000. The provisions of the 2005 plan are substantially the same as the prior plans. A 2006 plan and 2007 plan were established in 2004 with substantially similar terms to the 2005 plan.

        The iStar Financial Executive and Director High Performance Unit Program was established in 2003. This plan is substantially similar to the employee plans. There are two plans within the Executive and Director HPU Program, the 2005 plan and the 2006 plan. Each plan has 5,000 shares associated with it. Each share will carry 0.25 votes and pay dividends equal to 0.01 times the dividend paid on a share of our common stock, if and when dividends are declared on our common stock. The valuation date of the 2005 plan is December 31, 2005 and the valuation date of the 2006 plan is December 31, 2006. The valuation dates will be accelerated if there is a change of control of the Company. Prior to the valuation dates, the High Performance Common Stock will have little intrinsic value. Stockholders have been asked to consider and vote upon a proposal to expand the iStar Financial Executive and Director High Performance Unit Program by approving a 2007 Plan, a 2008 Plan and a 2009 Plan in this year's proxy statement.

        The shares will continue to have only the nominal value described above unless, on the applicable valuation date, the three-year total rate of return (dividends plus share price appreciation) on a share of our common stock exceeds the greater of: (1) 30.00%, and (2) a weighted industry index total rate of return consisting of equal weightings of the Russell 1000 Financial Index and the Morgan Stanley REIT Index for the three-year period. If the total rate of return on the common stock exceeds the threshold performance levels for a particular plan, then distributions are paid in the same manner as they are in the employee programs.

        The Executive and Director HPU Plans differ from the employee plans regarding dilution. The dilutive impact to our stockholders resulting from distributions on High Performance Common Stock in each plan under the Executive and Director HPU Plans will be limited to 0.50% of the number of shares of our common stock outstanding, on a fully diluted basis, on the valuation date for each plan, unlike the 1.00% limit in the employee plans.

Restrictions on Ownership and Transfer

        To maintain our REIT qualification under the Internal Revenue Code, no group of five or fewer individuals can own, actually or constructively, more than 50% in value of our issued and outstanding stock at any time during the last half of a taxable year. Additionally, at least 100 persons must beneficially own our stock (the "5/50 Test") during at least 335 days of a taxable year. To assist us in meeting these tests, our charter provides that no person other than persons who were our stockholders as of November 3, 1999 or persons exempted by our Board of Directors may beneficially or constructively own more than 9.8% of the number or value of our capital stock (the "Ownership Limit").

        Each person who is a beneficial or constructive owner of shares of stock and each person, including the stockholder of record, who is holding shares of stock for a beneficial or constructive owner must provide us in writing any information with respect to direct, indirect and constructive ownership of shares of stock as the Board of Directors deems reasonably necessary to comply with the provisions of the Internal Revenue Code applicable to a REIT, to determine our qualification as a REIT, to comply with the requirements of any taxing authority or governmental agency or to determine any such compliance.

        Any issuance or transfer of shares of our stock that would result in (1) a violation of the 5/50 Test, (2) our stock being beneficially owned by fewer than 100 persons (determined without reference to any rules of attribution), or (3) our otherwise failing to qualify as a REIT, shall be void and the intended

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transferee shall acquire no rights in such shares of our stock. Shares of our stock issued or transferred that would cause any stockholder (a "Prohibited Owner") to own more than the Ownership Limit or otherwise cause us to fail to qualify as a REIT will constitute shares of excess stock. All excess stock will be automatically transferred, without action by the Prohibited Owner, to a trust for the exclusive benefit of one or more charitable beneficiaries that we select, and the Prohibited Owner will not acquire any rights in the shares of excess stock. Such automatic transfer shall be deemed to be effective as of the close of business on the day prior to the date of the transfer causing a violation. If the transfer to the trust would not be effective for any reason to prevent a stockholder from owning more than the Ownership Limit or otherwise cause us to fail to qualify as a REIT, then the transfer of that number of shares necessary to cause such ownership or failure will be void and the intended transferee shall acquire no rights in such shares of our stock. The trustee of the trust shall be appointed by us and must be independent of us and the Prohibited Owner. The Prohibited Owner shall have no right to receive dividends or other distributions with respect to, or be entitled to vote, any excess stock held in the trust. Any dividend or other distribution paid prior to the discovery by us that excess stock has been transferred to the trust must be paid by the recipient of the dividend or distribution to the trustee upon demand for the benefit of the charitable beneficiaries, and any dividend or other distribution authorized but unpaid shall be paid when due to the trust. The trust shall have all dividend and voting rights with respect to the shares of excess stock held in the trust, which rights shall be exercised for the exclusive benefit of the charitable beneficiary. Any dividend or distribution so paid to the trust shall be held in trust for the charitable beneficiary.

        Within 60 days after the latest of (i) the date of the transfer which resulted in such transfer to the charitable trust and (ii) the date the Board of Directors determines in good faith that a transfer resulting in the transfer to the charitable trust has occurred, the trustee will sell the excess stock held in the trust to a person, designated by the trustee, whose ownership of the shares will not violate the ownership limitations set forth in our charter. Upon such sale, any interest of the charitable beneficiary in the excess stock sold shall terminate and the trustee shall distribute the net proceeds of the sale to the Prohibited Owner and to the charitable beneficiary as follows. The Prohibited Owner shall receive the lesser of (a) the price paid by the Prohibited Owner for the excess stock (or, in the case of a devise, gift or other transaction in which no value was given for such shares held by the charitable trust, the Market Price (as defined in our charter) at the time of such devise, gift or other transaction), and (b) the price per share received by the trustee from the sale or other disposition of the excess stock held in the trust. Any net sale proceeds in excess of the amount payable to the Prohibited Owner shall be paid immediately to the charitable beneficiary. Shares of our stock held by the charitable trust shall be deemed to have been offered for sale to us, or our designee, at a price per share equal to the lesser of (i) the price per share in the transaction that created such shares held by the trust (or, in the case of a devise, gift or other transaction in which no value was given for such shares held by the trust, the Market Price at the time of such devise, gift or other transaction) and (ii) the Market Price of the shares of our stock to which such shares held by the trust relates on the date we, or our designee, accepts such offer (the "Redemption Price"). We shall have the right to accept such offer until the trustee has sold the shares of our stock held in the charitable trust. Upon such a sale, the interest of the charitable beneficiary in the shares of stock sold shall terminate and the trustee shall distribute the net proceeds of the sale to the purported record transferee of such shares. If any of the foregoing restrictions on transfer of our shares held by the trust are determined to be void or invalid, then the purported record transferee of such shares may be deemed, at our option, to have acted as our agent in acquiring such shares and to hold such shares on our behalf.

        These restrictions on ownership and transfer will not apply to our stock if the Board of Directors determines that it is no longer in our best interests to qualify as a REIT.

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        These restrictions on ownership and transfer could delay, defer or prevent a transaction or a change of control of us that might involve a premium price for shares of our stock or otherwise be in the best interest of our stockholders.

Preferred Stock

        We may issue preferred stock in series with any rights and preferences which may be authorized by our board of directors. We will distribute a prospectus supplement with regard to each series of preferred stock. Each prospectus supplement will describe, as to the preferred stock to which it relates:

        Holders of shares of preferred stock will not have preemptive rights.

Transfer Agent and Registrar

        The transfer agent and registrar for our common stock and preferred stock is Equiserve Trust Company, N.A.

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DESCRIPTION OF DEPOSITARY SHARES

        We may issue depositary receipts representing interests in shares of particular series of preferred stock which are called depositary shares. We will deposit the preferred stock of a series which is the subject of depositary shares with a depositary, which will hold that preferred stock for the benefit of the holders of the depositary shares, in accordance with a deposit agreement between the depositary and us. The holders of depositary shares will be entitled to all the rights and preferences of the preferred stock to which the depositary shares relate, including dividend, voting, conversion, redemption and liquidation rights, to the extent of their interests in that preferred stock.

        While the deposit agreement relating to a particular series of preferred stock may have provisions applicable solely to that series of preferred stock, all deposit agreements relating to preferred stock we issue will include the following provisions:

        Dividends and Other Distributions.    Each time we pay a cash dividend or make any other type of cash distribution with regard to preferred stock of a series, the depositary will distribute to the holder of record of each depositary share relating to that series of preferred stock an amount equal to the dividend or other distribution per depositary share the depositary receives. If there is a distribution of property other than cash, the depositary either will distribute the property to the holders of depositary shares in proportion to the depositary shares held by each of them, or the depositary will, if we approve, sell the property and distribute the net proceeds to the holders of the depositary shares in proportion to the depositary shares held by them.

        Withdrawal of Preferred Stock. A holder of depositary shares will be entitled to receive, upon surrender of depositary receipts representing depositary shares, the number of whole or fractional shares of the applicable series of preferred stock, and any money or other property, to which the depositary shares relate.

        Redemption of Depositary Shares.    Whenever we redeem shares of preferred stock held by a depositary, the depositary will be required to redeem, on the same redemption date, depositary shares constituting, in total, the number of shares of preferred stock held by the depositary which we redeem, subject to the depositary's receiving the redemption price of those shares of preferred stock. If fewer than all the depositary shares relating to a series are to be redeemed, the depositary shares to be redeemed will be selected by lot or by another method we determine to be equitable.

        Voting.    Any time we send a notice of meeting or other materials relating to a meeting to the holders of a series of preferred stock to which depositary shares relate, we will provide the depositary with sufficient copies of those materials so they can be sent to all holders of record of the applicable depositary shares, and the depositary will send those materials to the holders of record of the depositary shares on the record date for the meeting. The depositary will solicit voting instructions from holders of depositary shares and will vote or not vote the preferred stock to which the depositary shares relate in accordance with those instructions.

        Liquidation Preference.    Upon our liquidation, dissolution or winding up, the holder of each depositary share will be entitled to what the holder of the depositary share would have received if the holder had owned the number of shares (or fraction of a share) of preferred stock which is represented by the depositary share.

        Conversion.    If shares of a series of preferred stock are convertible into common stock or other of our securities or property, holders of depositary shares relating to that series of preferred stock will, if they surrender depositary receipts representing depositary shares and appropriate instructions to convert them, receive the shares of common stock or other securities or property into which the number of shares (or fractions of shares) of preferred stock to which the depositary shares relate could at the time be converted.

        Amendment and Termination of a Deposit Agreement.    We and the depositary may amend a deposit agreement, except that an amendment which materially and adversely affects the rights of

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holders of depositary shares, or would be materially and adversely inconsistent with the rights granted to the holders of the preferred stock to which they relate, must be approved by holders of at least two-thirds of the outstanding depositary shares. No amendment will impair the right of a holder of depositary shares to surrender the depositary receipts evidencing those depositary shares and receive the preferred stock to which they relate, except as required to comply with law. We may terminate a deposit agreement with the consent of holders of a majority of the depositary shares to which it relates. Upon termination of a deposit agreement, the depositary will make the whole or fractional shares of preferred stock to which the depositary shares issued under the deposit agreement relate available to the holders of those depositary shares. A deposit agreement will automatically terminate if:

        Miscellaneous.    There will be provisions: (1) requiring the depositary to forward to holders of record of depositary shares any reports or communications from us which the depositary receives with respect to the preferred stock to which the depositary shares relate; (2) regarding compensation of the depositary; (3) regarding resignation of the depositary; (4) limiting our liability and the liability of the depositary under the deposit agreement (usually to failure to act in good faith, gross negligence or willful misconduct); and (5) indemnifying the depositary against certain possible liabilities.


CERTAIN U.S. FEDERAL INCOME TAX CONSEQUENCES

        THE FOLLOWING IS A SUMMARY OF THE U.S. FEDERAL INCOME TAX CONSEQUENCES RELEVANT TO AN INVESTOR IN iSTAR FINANCIAL AND OUR QUALIFICATION AS A REIT. THIS SUMMARY IS BASED ON CURRENT LAW. YOUR TAX CONSEQUENCES RELATED TO AN INVESTMENT IN iSTAR FINANCIAL MAY VARY DEPENDING ON YOUR PARTICULAR SITUATION AND THIS DISCUSSION DOES NOT PURPORT TO DISCUSS ALL ASPECTS OF TAXATION THAT MAY BE RELEVANT TO A HOLDER OF OUR SECURITIES IN LIGHT OF HIS OR HER PERSONAL INVESTMENT OR TAX CIRCUMSTANCES, OR TO HOLDERS OF OUR SECURITIES SUBJECT TO SPECIAL TREATMENT UNDER THE U.S. FEDERAL INCOME TAX LAWS, EXCEPT TO THE EXTENT DISCUSSED UNDER THE HEADINGS "—TAXATION OF TAX-EXEMPT STOCKHOLDERS" AND "—TAXATION OF NON-U.S. STOCKHOLDERS." INVESTORS SUBJECT TO SPECIAL TREATMENT INCLUDE, WITHOUT LIMITATION, INSURANCE COMPANIES, FINANCIAL INSTITUTIONS, BROKER-DEALERS, TAX-EXEMPT ORGANIZATIONS, INVESTORS HOLDING SECURITIES AS PART OF A CONVERSION TRANSACTION, OR A HEDGE OR HEDGING TRANSACTION OR AS A POSITION IN A STRADDLE FOR TAX PURPOSES, FOREIGN CORPORATIONS OR PARTNERSHIPS, AND PERSONS WHO ARE NOT CITIZENS OR RESIDENTS OF THE UNITED STATES. IN ADDITION, THE SUMMARY BELOW DOES NOT CONSIDER THE EFFECT OF ANY FOREIGN, STATE, LOCAL OR OTHER TAX LAWS THAT MAY BE APPLICABLE TO YOU AS A HOLDER OF OUR SECURITIES.

        This discussion is based on the Internal Revenue Code, current, temporary and proposed Treasury regulations promulgated under the Internal Revenue Code, the legislative history of the Internal Revenue Code, current administrative interpretations and practices of the Internal Revenue Service, and court decisions, all as of the date of this prospectus. The administrative interpretations and practices of the Internal Revenue Service upon which this summary is based include its practices and policies as expressed in private letter rulings which are not binding on the Internal Revenue Service, except with respect to the taxpayers who requested and received such rulings. Future legislation, Treasury regulations, administrative interpretations and practices, and court decisions may affect the tax consequences contained in this summary, possibly on a retroactive basis. We have not requested, and do not plan to request, any rulings from the Internal Revenue Service concerning our tax treatment or the tax consequences contained in this summary, and the statements in this prospectus are not binding

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on the Internal Revenue Service or a court. Thus, we can provide no assurance that the tax consequences contained in this summary will not be challenged by the Internal Revenue Service or sustained by a court if so challenged.

        YOU ARE URGED TO CONSULT YOUR TAX ADVISOR REGARDING THE SPECIFIC TAX CONSEQUENCES TO YOU OF: (1) THE ACQUISITION, OWNERSHIP AND SALE OR OTHER DISPOSITION OF OUR SECURITIES, INCLUDING THE U.S. FEDERAL, STATE, LOCAL, FOREIGN AND OTHER TAX CONSEQUENCES; (2) OUR ELECTION TO BE TAXED AS A REIT FOR U.S. FEDERAL INCOME TAX PURPOSES; AND (3) POTENTIAL CHANGES IN APPLICABLE TAX LAWS.

Taxation of iStar Financial—General

        We have elected to be taxed as a REIT under Sections 856 through 860 of the Internal Revenues Code, commencing with our taxable year ended December 31, 1998. We believe that we have been organized and have operated in a manner which allows us to qualify for taxation as a REIT under the Internal Revenue Code and we intend to continue to be organized and to operate in this manner. Our qualification and taxation as a REIT, however, depend upon our ability to meet, through actual annual operating results, asset requirements, distribution levels, diversity of stock ownership, and the various other requirements imposed under the Internal Revenue Code. Accordingly, there can be no assurance that we have operated or will continue to operate in a manner so as to qualify or remain qualified as a REIT. See "—Failure to Qualify."

        In the opinion of Clifford Chance US LLP, commencing with our taxable year ended December 31, 1998, iStar Financial was organized and has operated in conformity with the requirements for qualification as a REIT, and its present and proposed method of operation, as represented by iStar Financial, will enable it to meet the requirements for qualification as a REIT under the Internal Revenue Code. It must be emphasized that this opinion is based and conditioned upon certain assumptions and representations made by us as to factual matters (including our representations concerning our income and properties and the past, present, and future conduct of our business operations as set forth in this prospectus and one or more factual certificates provided by our officers). The opinion is expressed as of its date and Clifford Chance US LLP has no obligation to advise of any subsequent change in the matters stated, represented or assumed or any subsequent change in the applicable law. Moreover, such qualification and taxation as a REIT depends upon our ability to meet, through actual annual operating results, distribution levels and diversity of stock ownership, the various requirements imposed under the Internal Revenue Code as discussed below, the results of which will not be reviewed by Clifford Chance US LLP. Accordingly, no assurance can be given that the actual results of our operation for any one taxable year will satisfy such requirements. See "—Failure to Qualify." An opinion of counsel is not binding on the Internal Revenue Service, and no assurance can be given that the Internal Revenue Service will not challenge our qualification as a REIT.

        The sections of the Internal Revenue Code that relate to the qualification and taxation of REITs are highly technical and complex. The following describes the material aspects of the sections of the Internal Revenue Code that govern the U.S. federal income tax treatment of a REIT and its stockholders. This summary is qualified in its entirety by the applicable Internal Revenue Code provisions, rules and regulations promulgated under the Internal Revenue Code, and administrative and judicial interpretations of the Internal Revenue Code.

        Provided we qualify for taxation as a REIT, we generally will not be subject to U.S. federal corporate income tax on our net income that is currently distributed to our stockholders. This treatment substantially eliminates the "double taxation" that generally results from an investment in a corporation. Double taxation means taxation once at the corporate level when income is earned and once again at the stockholder level when such income is distributed. For tax years through 2008, stockholders who are individual U.S. stockholders (as defined below) are generally taxed on corporate dividends at a maximum rate of 15% (the same as long-term capital gains), thereby substantially

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reducing, though not completely eliminating, the double taxation that has historically applied to corporate dividends. With limited exceptions, however, dividends received from us or other entities that are taxed as REITs will continue to be taxed at rates applicable to ordinary income, which will be as high as 35% through 2010.

        Even if we qualify for taxation as a REIT, however, we will be subject to U.S. federal income taxation as follows:

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        In addition, our subsidiaries and we may be subject to a variety of taxes other than U.S. federal income tax, including payroll taxes and state, local, and foreign income, franchise property and other taxes. We could also be subject to tax in situations and on transactions not presently contemplated.

Requirements for Qualification as a REIT

General

        The Internal Revenue Code defines a REIT as a corporation, trust or association:


        The Internal Revenue Code provides that conditions (1) to (4) must be met during the entire year and that condition (5) must be met during at least 335 days of a year of twelve months, or during a proportionate part of a shorter taxable year. Conditions (5) and (6) do not apply to the first taxable year for which an election is made to be taxed as a REIT.

        We believe that we currently satisfy conditions (1) through (7) above. In addition, our Charter provides for restrictions regarding ownership and transfer of our stock. These restrictions are intended to assist us in satisfying the share ownership requirements described in (5) and (6) above. These restrictions, however, may not ensure that we will, in all cases, be able to satisfy the share ownership requirements described in (5) and (6) above. If we fail to satisfy these share ownership requirements, our status as a REIT would terminate. If, however, we comply with the rules contained in applicable Treasury regulations that require us to determine the actual ownership of our shares and we do not know, or would not have known through the exercise of reasonable diligence, that we failed to meet the requirement described in condition (6) above, we would not be disqualified as a REIT.

        In addition, a corporation may not qualify as a REIT unless its taxable year is the calendar year. We have and will continue to have a calendar taxable year.

Effect of Subsidiary Entities

Ownership of a Partnership Interest

        In the case of a REIT that is a partner in a partnership, Treasury regulations provide that the REIT is deemed to own its proportionate share of the partnership's assets and to earn its

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proportionate share of the partnership's gross income based on its pro rata share of capital interests in the partnership for purposes of the REIT asset and gross income tests described below. In addition, the assets and gross income of the partnership generally are deemed to retain the same character in the hands of the REIT. For purposes of the 10% value test only, however, the determination of a REIT's interest in partnership assets will be based on the REIT's proportionate interest in any securities issued by the partnership, excluding certain securities described in the Internal Revenue Code. Thus, our proportionate share of the assets and income of partnerships in which we own an equity interest are treated as our assets and items of income for purposes of applying the REIT asset and gross income requirements described below. Consequently, to the extent that we directly or indirectly hold a preferred or other equity interest in a partnership, the partnership's assets and operations may affect our ability to qualify as a REIT, even though we may have no control, or only limited influence, over the partnership. A summary of certain rules governing the U.S. federal income taxation of partnerships and their partners is provided below in "—Tax Aspects of Investments in Partnerships."

Qualified REIT Subsidiaries.

        A "qualified REIT subsidiary" is a corporation, all of the stock of which is owned by a REIT. Under the Internal Revenue Code, a qualified REIT subsidiary is not treated as a separate corporation from the REIT. Rather, all of the assets, liabilities, and items of income, deduction, and credit of the qualified REIT subsidiary are treated as the assets, liabilities, and items of income, deduction, and credit of the REIT for purposes of the REIT income and asset tests described below.

Taxable REIT Subsidiaries.

        A "taxable REIT subsidiary" is a corporation which, together with a REIT that owns an interest in such corporation, makes an election to be treated as a taxable REIT subsidiary. A taxable REIT subsidiary may earn income that would be nonqualifying income if earned directly by a REIT and is generally subject to full corporate level tax. A REIT may own up to 100% of the stock of a taxable REIT subsidiary.

        Certain restrictions imposed on taxable REIT subsidiaries are intended to ensure that such entities will be subject to appropriate levels of U.S. federal income taxation. First, if a taxable REIT subsidiary has a debt to equity ratio as of the close of the taxable year exceeding 1.5 to 1, it may not deduct interest payments made in any year to an affiliated REIT to the extent that such payments exceed, generally, 50% of the taxable REIT subsidiary's adjusted taxable income for that year (although the taxable REIT subsidiary may carry forward to, and deduct in, a succeeding year the disallowed interest amount if the 50% test is satisfied in that year). In addition, if a taxable REIT subsidiary pays interest, rent or another amount to a REIT that exceeds the amount that would be paid to an unrelated party in an arm's length transaction, the REIT generally will be subject to an excise tax equal to 100% of such excess.

Taxable Mortgage Pools

        An entity, or a portion of an entity, may be classified as a taxable mortgage pool under the Internal Revenue Code if:


        Under Treasury regulations, if less than 80% of the assets of an entity (or a portion of an entity) consist of debt obligations, these debt obligations are considered not to comprise "substantially all" of its assets, and therefore the entity would not be treated as a taxable mortgage pool.

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        A taxable mortgage pool generally is treated as a corporation for U.S. federal income tax purposes. However, special rules apply to a REIT, a portion of a REIT, or a qualified REIT subsidiary that is a taxable mortgage pool. If a REIT owns directly, or indirectly through one or more qualified REIT subsidiaries or other entities that are disregarded as a separate entity for U.S. federal income tax purposes, 100% of the equity interests in the taxable mortgage pool, the taxable mortgage pool will be a qualified REIT subsidiary and, therefore, ignored as an entity separate from the REIT for U.S. federal income tax purposes and would not generally affect the tax qualification of the REIT. Rather, the consequences of the taxable mortgage pool classification would generally, except as described below, be limited to the REIT's stockholders. See "—Excess Inclusion Income."

        If we own less than 100% of the ownership interests in a subsidiary that is a taxable mortgage pool, the foregoing rules would not apply. Rather, the subsidiary would be treated as a corporation for U.S. federal income tax purposes, and would potentially be subject to corporate income tax. In addition, this characterization would alter our REIT income and asset test calculations and could adversely affect our compliance with those requirements. We do not expect that we would form any subsidiary in which we own some, but less than all, of the ownership interests that would become a taxable mortgage pool, and we intend to monitor the structure of any taxable mortgage pools in which we have an interest to ensure that they will not adversely affect our qualification as a REIT.

Income Tests

        We must meet two annual gross income requirements to qualify as a REIT. First, each year we must derive at least 75% of our gross income, excluding gross income from prohibited transactions, from investments relating to real property or mortgages on real property, including "rents from real property" and mortgage interest, or from specified temporary investments. Second, each year we must derive at least 95% of our gross income, excluding gross income from prohibited transactions, from investments meeting the 75% test described above, or from dividends, interest and gain from the sale or disposition of stock or securities. For these purposes, the term "interest" generally does not include any interest of which the amount received depends on the income or profits of any person. An amount will generally not be excluded from the term "interest," however, if such amount is based on a fixed percentage of gross receipts or sales.

        Any amount includable in gross income by us with respect to a regular or residual interest in a REMIC is generally treated as interest on an obligation secured by a mortgage on real property for purposes of the 75% gross income test. If, however, less than 95% of the assets of a REMIC consist of real estate assets, we will be treated as receiving directly our proportionate share of the income of the REMIC, which would generally include non-qualifying income for purposes of the 75% gross income test. In addition, if we receive interest income with respect to a mortgage loan that is secured by both real property and other property and the principal amount of the loan exceeds the fair market value of the real property on the date we made the mortgage loan, interest income on the loan will be apportioned between the real property and the other property, which apportionment would cause us to recognize income that is not qualifying income for purposes of the 75% gross income test.

        We may make loans that have shared appreciation provisions. To the extent interest on a loan is based on the cash proceeds from the sale or value of property, income attributable to such provision would be treated as gain from the sale of the secured property, which generally should qualify for purposes of the 75% and 95% gross income tests.

        Lease income we receive will qualify as "rents from real property" only if the following conditions are met:

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        We intend to maintain our REIT status by carefully monitoring any potential nonqualifying income for purposes of the 75% and 95% gross income tests discussed above. If we fail to satisfy one or both of the 75% or 95% gross income tests for any year, we may still qualify as a REIT if we are entitled to relief under the Internal Revenue Code. Generally, we may be entitled to relief if:

        Beginning with our 2005 tax year, if we fail to satisfy one or both of the 75% or 95% gross income tests for any year, we may still qualify as a REIT if our failure to meet these tests was due to reasonable cause and not due to willful neglect and, following the identification of such failure, we set forth a description of each item of our gross income that satisfies the gross income tests in a schedule for the taxable year filed in accordance with regulations prescribed by the Treasury.

        It is not possible to state whether in all circumstances we would be entitled to rely on these relief provisions. If these relief provisions do not apply to a particular set of circumstances, we would not qualify as a REIT. As discussed above in "—Taxation of iStar Financial—General," even if these relief provisions apply, and we retain our status as a REIT, a tax would be imposed with respect to our income that does not meet the gross income tests. We may not always be able to maintain compliance with the gross income tests for REIT qualification despite periodically monitoring our income.

Foreclosure Property

        Net income realized by us from foreclosure property would generally be subject to tax at the maximum U.S. federal corporate tax rate (currently 35%). Foreclosure property means real property and related personal property that: (1) is acquired by us through foreclosure following a default on a lease of such property or a default on indebtedness owed to us that is secured by the property; and (2) for which we make an election to treat the property as foreclosure property.

Prohibited Transaction Income

        Any gain realized by us on the sale of any property, other than foreclosure property, held as inventory or otherwise held primarily for sale to customers in the ordinary course of business will be prohibited transaction income, and subject to a 100% penalty tax. Prohibited transaction income may also adversely affect our ability to satisfy the gross income tests for qualification as a REIT. Whether

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property is held as inventory or primarily for sale to customers in the ordinary course of a trade or business depends on all the facts and circumstances surrounding the particular transaction. While the Internal Revenue Code provides standards which, if met, would not result in prohibited transaction income, we may not be able to meet these standards in all circumstances.

Hedging Transactions

        We may enter into hedging transactions with respect to one or more of our assets or liabilities. Our hedging transactions could take a variety of forms, including interest rate swaps or cap agreements, options, futures contracts, forward rate agreements, or similar financial instruments. Except to the extent provided by Treasury regulations, any income from a hedging transaction to manage risk of interest rate or price changes or currency fluctuations with respect to borrowings made or to be made, or ordinary obligations incurred or to be incurred by us to acquire or own real estate assets, which is clearly identified as such before the close of the day on which it was acquired, originated or entered into, including gain from the disposition of such a transaction, will not constitute gross income for purposes of the 95% gross income test (but generally will constitute non-qualifying gross income for purposes of the 75% income test). To the extent we enter into other types of hedging transactions, the income from those transactions is likely to be treated as non-qualifying income for purposes of both the 75% and 95% gross income tests. We intend to structure any hedging transactions in a manner that does not jeopardize our ability to qualify as a REIT.

Excess Inclusion Income

        If we are deemed to have issued debt obligations having two or more maturities, the payments on which correspond to payments on mortgage loans owned by us, such arrangement may be treated as a taxable mortgage pool for U.S. federal income tax purposes. If all or a portion of our company is considered a taxable mortgage pool, our status as a REIT generally should not be impaired; however, a portion of our taxable income may be characterized as "excess inclusion income" and allocated to our stockholders. In addition, if we acquire any residual interest in a REMIC, a portion of our income derived from such residual interest may also be characterized as excess inclusion income. Any excess inclusion income:


Asset Tests

        At the close of each quarter of each of our taxable years, we must satisfy four tests relating to the nature and diversification of our assets. First, at least 75% of the value of our total assets must be real estate assets, cash, cash items and government securities. For purposes of this test, real estate assets include real estate mortgages, real property, interests in other REITs and stock or debt instruments held for one year or less that are purchased with the proceeds of a stock offering or a long-term public debt offering. In addition, any regular or residual interests we hold in a REMIC are generally treated as a real estate asset for purposes of the asset tests described above. If, however, less than 95% of the assets of a REMIC consist of real estate assets, we will be treated as holding our proportionate share of the assets of the REMIC, which generally would include assets both qualifying and not qualifying as real estate assets. Second, not more than 25% of our total assets may be represented by securities, other than those securities includable in the 75% asset class. Third, of the investments included in the

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25% asset class and, except for investments in REITs, qualified REIT subsidiaries and taxable REIT subsidiaries, the value of any one issuer's securities that we hold may not exceed 5% of the value of our total assets, and we may not own more than 10% of the total vote or value of the outstanding securities of any one issuer. Fourth, not more than 20% of the value of our total assets may be represented by securities in one or more taxable REIT subsidiaries.

        The 5% and 10% asset tests do not apply to securities of taxable REIT subsidiaries, qualified REIT subsidiaries or securities that are "real estate assets" for purposes of the 75% gross asset test described above. The 10% value test does not apply to certain "straight debt" and other excluded securities, as described in the Internal Revenue Code including, but not limited to, any loan to an individual or estate, any obligation to pay rents from real property and any security issued by a REIT. In addition, (a) a REIT's interest as a partner in a partnership is not considered a security for purposes of applying the 10% value test to securities issued by the partnership, (b) any debt instrument issued by a partnership (other than straight debt or another excluded security) will not be considered a security issued by the partnership if at least 75% of the partnership's gross income is derived from sources that would qualify for the 75% REIT gross income test, and (c) any debt instrument issued by a partnership (other than straight debt or another excluded security) will not be considered a security issued by the partnership to the extent of the REIT's interest as a partner in the partnership.

        For purposes of the 10% value test, "straight debt" means a written unconditional promise to pay on demand on a specified date a sum certain in money if (i) the debt is not convertible, directly or indirectly, into stock, (ii) the interest rate and interest payment dates are not contingent on profits, the borrower's discretion, or similar factors other than certain contingencies relating to the timing and amount of principal and interest payments, as described in the Internal Revenue Code and (iii) in the case of an issuer which is a corporation or a partnership, securities that otherwise would be considered straight debt will not be so considered if we, and any of our "controlled taxable REIT subsidiaries" as defined in the Internal Revenue Code, hold any securities of the corporate or partnership issuer which: (a) are not straight debt or other excluded securities (prior to the application of this rule), and (b) have an aggregate value greater than 1% of the issuer's outstanding securities (including, for the purposes of a partnership issuer, our interest as a partner in the partnership).

        We expect that any real property and temporary investments that we acquire will generally be qualifying assets for purposes of the 75% asset test, except to the extent that less than 95% of the assets of a REMIC in which we own an interest consists of "real estate assets." Mortgage loans will generally be qualifying assets for purposes of the 75% asset test to the extent that the principal balance of each mortgage loan does not exceed the value of the associated real property.

        The asset tests must be satisfied not only on the last day of the calendar quarter in which we acquire securities in the applicable issuer, but also on the last day of the calendar quarter in which we increase our ownership of securities of such issuer. After initially meeting the asset tests at the close of any quarter, we will not lose our status as a REIT for failure to satisfy the asset tests at the end of a later quarter solely by reason of changes in asset values. If we fail to satisfy an asset test because we acquire securities or other property during a quarter, we can cure this failure by disposing of sufficient non-qualifying assets within 30 days after the close of the quarter. If we fail the 5% asset test or the 10% asset test at the end of any quarter, and the such failure is not cured within 30 days thereafter, we may dispose of sufficient assets (generally, within six months after the last day of the quarter in which our identification of the failure to satisfy those asset tests occurred) to cure the violation, provided that the non-permitted assets do not exceed the lesser of 1% of our assets at the end of the relevant quarter or $10,000,000. If we fail any of the other asset tests, or our failure of the 5% and 10% asset tests is in excess of this amount, as long as the failure was due to reasonable cause and not willful neglect, we are permitted to avoid disqualification as a REIT, after the thirty day cure period, by taking steps, including the disposition of sufficient assets to meet the asset tests (generally within six months after the last day of the quarter in which our identification of the failure to satisfy the REIT asset test

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occurred), and paying a tax equal to the greater of $50,000 or 35% of the net income generated by the nonqualifying assets during the period in which we failed to satisfy the relevant asset test.

        We believe that our holdings of securities and other assets will comply with the foregoing REIT asset test requirements, and we intend to monitor our compliance with such tests on an ongoing basis. However, the values of some of our assets may not be precisely valued, and values are subject to change in the future. Furthermore, the proper classification of an instrument as debt or equity for U.S. federal income tax purposes may be uncertain in some circumstances, which could affect the application of the REIT asset tests. Accordingly, there can be no assurance that the Internal Revenue Service will not contend that our assets do not meet the requirements of the REIT asset tests.

Annual Distribution Requirements

        To qualify as a REIT, we are required to distribute dividends, other than capital gain dividends, to our stockholders in an amount at least equal to the sum of: (1) 90% of our "REIT taxable income"; and (2) 90% of our after tax net income, if any, from foreclosure property; minus (3) the excess of the sum of certain items of non-cash income over 5% of our "REIT taxable income". In general, "REIT taxable income" means taxable ordinary income without regard to the dividends paid deduction.

        We are required to distribute income in the taxable year in which it is earned, or in the following taxable year if such dividend distributions are declared in October, November or December of the taxable year, payable to stockholders of record on a specified date during such period and paid during January of the following year. Such distributions are treated as paid by us and received by our stockholders on December 31 of the year in which they are declared. In addition, at our election, a distribution for a taxable year may be declared before we timely file our tax return and paid on or before our first regular dividend payment following such declaration, provided such payment is made during the twelve-month period following the close of our taxable year. These distributions are taxable to holders of common stock in the year in which paid, even though these distributions relate to our prior year for purposes of our 90% distribution requirement. To the extent that we do not distribute all of our net capital gain or distribute at least 90%, but less than 100% of our "REIT taxable income," we will be subject to tax at regular corporate tax rates.

        From time to time we may not have sufficient cash or other liquid assets to meet the above distribution requirements due to timing differences between the actual receipt of cash and payment of expenses, and the inclusion of income and deduction of expenses in arriving at our taxable income. If these timing differences occur, in order to meet the REIT distribution requirements, we may need to arrange for short-term, or possibly long-term, borrowings, or to pay dividends in the form of taxable stock dividends.

        Under certain circumstances, we may be able to rectify a failure to meet a distribution requirement for a year by paying "deficiency dividends" to our stockholders in a later year, which may be included in our deduction for dividends paid for the earlier year. Thus, we may be able to avoid being subject to tax on amounts distributed as deficiency dividends. We will be required, however, to pay interest based upon the amount of any deduction claimed for deficiency dividends. In addition, we will be subject to a 4% excise tax on the excess of the required distribution over the amounts actually distributed if we should fail to distribute each year at least the sum of 85% of our ordinary income for the year, 95% of our capital gain income for the year, and any undistributed taxable income from prior periods.

Recordkeeping Requirements

        We are required to maintain records and request on an annual basis information from specified stockholders. These requirements are designed to assist us in determining the actual ownership of our outstanding stock and maintaining our qualifications as a REIT.

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Failure to Qualify

        In the event we violate a provision of the Internal Revenue Code that would result in our failure to qualify as a REIT, specified relief provisions will be available to us to avoid such disqualification if (1) the violation is due to reasonable cause, (2) we pay a penalty of $50,000 for each failure to satisfy the provision and (3) the violation does not include a violation of the gross income or asset tests described above (for which other specified relief provisions are available). This cure provision reduces the instances that could lead to our disqualification as a REIT for violations due to reasonable cause.

        If we fail to qualify for taxation as a REIT in any taxable year, and the relief provisions of the Internal Revenue Code do not apply, we will be subject to tax, including any applicable alternative minimum tax, and possibly increased state and local taxes, on our taxable income at regular corporate rates. Such taxation would reduce the cash available for distribution by us to our stockholders. Distributions to our stockholders in any year in which we fail to qualify as a REIT will not be deductible by us and we will not be required to distribute any amounts to our stockholders. In this situation, to the extent of current and accumulated earnings and profits, and, subject to limitations of the Internal Revenue Code, distributions to our stockholders through 2008 will generally be taxable to stockholders who are individual U.S. stockholders at a maximum rate of 15%, and dividends received by our corporate U.S. stockholders may be eligible for the dividends received deduction. Unless entitled to relief under specific statutory provisions, we would also be disqualified from taxation as a REIT for the four taxable years following the year during which we lost our qualification. It is not possible to state whether in all circumstances we would be entitled to statutory relief.

Tax Aspects of Investments in Partnerships

General

        We may hold investments through entities that are classified as partnerships for U.S. federal income tax purposes. In general, partnerships are "pass-through" entities that are not subject to U.S. federal income tax. Rather, partners are allocated their proportionate shares of the items of income, gain, loss, deduction and credit of a partnership, and are subject to tax on such items without regard to whether the partners receive a distribution from the partnership. We will include in our income our proportionate share of these partnership items for purposes of the various REIT gross income tests, based on our capital interest in such partnership, and we will include our share of partnership items in our computation of our taxable income. Moreover, for purposes of the REIT asset tests, we will include our proportionate share of assets held by subsidiary partnerships (other than for purposes of the 10% value test, for which the determination of our interest in partnership assets will be based on our proportionate interest in any securities issued by the partnership, excluding for these purposes, certain excluded securities as described in the Internal Revenue Code). See "—Effect of Subsidiary Entities—Ownership of a Partnership Interest" above. Consequently, to the extent that we hold an equity interest in a partnership, the partnership's assets and operations may affect our ability to qualify as a REIT, even though we may have no control, or only limited influence, over the partnership.

Entity Classification

        The investment by us in partnerships involves special tax considerations, including the possibility of a challenge by the Internal Revenue Service of the status of any of our subsidiary partnerships as a partnership, as opposed to an association taxable as a corporation, for U.S. federal income tax purposes. If any of these entities were treated as an association for U.S. federal income tax purposes, it would be taxable as a corporation and, therefore, would be subject to an entity-level tax on its net income. In such a situation, the character of our assets and items of our gross income would change and could preclude us from satisfying the REIT asset tests (particularly the tests generally preventing a REIT from owning more than 10% of the voting securities, or more than 10% of the value of the securities, of a corporation) or the gross income tests as discussed in "—Requirements for Qualification as a REIT—Asset Tests" and "—Income Tests" above, and in turn could prevent us from qualifying as

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a REIT. See "—Requirements for Qualification as a REIT—Failure to Qualify," below, for a discussion of the effect of our failure to meet these tests for a taxable year. In addition, any change in the status of any of our subsidiary partnerships for U.S. federal income tax purposes might be treated as a taxable event, in which case we could have taxable income that is subject to the REIT distribution requirements without receiving any cash.

Allocations with Respect to Partnership Properties

        Under the Internal Revenue Code and the Treasury regulations, income, gain, loss and deduction attributable to appreciated or depreciated property that is contributed to a partnership in exchange for an interest in the partnership must be allocated for tax purposes in a manner such that the contributing partner is charged with, or benefits from, the unrealized gain or unrealized loss associated with the property at the time of the contribution. The amount of the unrealized gain or unrealized loss is generally equal to the difference between the fair market value of the contributed property and the adjusted tax basis of such property at the time of the contribution (a "book-tax difference"). Such allocations are solely for U.S. federal income tax purposes and do not affect the partnership's capital accounts or the other economic or legal arrangements among the partners.

        To the extent that any of our subsidiary partnerships acquire appreciated (or depreciated) properties by way of capital contributions, allocations would need to be made in a manner consistent with these requirements. As a result, we could be allocated greater or lesser amounts of depreciation and taxable income in respect of such contributed properties than would have been the case if all of the partnership's assets had been acquired in exchange for cash at their agreed upon fair market value.

Taxation of Taxable U.S. Stockholders

        When we use the term "U.S. stockholder," we mean a beneficial owner of shares of our stock who is, for U.S. federal income tax purposes:

        If a partnership holds shares of our stock, the tax treatment of a partner in the partnership will generally depend upon the status of the partner and the activities of the partnership. If you are a partner of a partnership holding shares of our stock, you should consult your tax advisor regarding the consequences of the ownership and disposition of shares of our stock.

Distributions Generally

        Distributions out of our current or accumulated earnings and profits, other than capital gain dividends will generally be taxable to our U.S. stockholders as ordinary income. For this purpose, our earnings and profits will be allocated first to our outstanding preferred shares, and then to our outstanding common shares. Provided we qualify as a REIT, our dividends will not be eligible for the dividends received deduction generally available to U.S. stockholders that are corporations.

        Dividends received from REITs are generally not eligible to be taxed at the preferential qualified dividend income rates applicable to individual U.S. stockholders who receive dividends from taxable C corporations. An exception applies, however, and individual U.S. stockholders are taxed at such rates

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on dividends designated by and received from REITs, to the extent that the dividends are attributable to (i) "REIT taxable income" that the REIT previously retained in the prior year, and on which it was subject to corporate level tax, (ii) dividends received by the REIT from taxable domestic C corporations (including taxable REIT subsidiaries) and certain foreign corporations or (iii) income from sales of appreciated property acquired from C corporations in carryover basis transactions that has been subject to tax at the REIT level.

        To the extent that we make distributions in excess of our current and accumulated earnings and profits, these distributions will be treated as a tax-free return of capital to each U.S. stockholder, and will reduce the adjusted tax basis which each U.S. stockholder has in its shares of stock by the amount of the distribution, but not below zero. Return of capital distributions in excess of a U.S. stockholder's adjusted tax basis in its shares will be taxable as capital gain, provided that the shares have been held as capital assets, and will be taxable as long-term capital gain if the shares have been held for more than one year.

        Dividends we declare in October, November, or December of any year and pay to a stockholder of record on a specified date in any of those months will be treated as both paid by us and received by the stockholder on December 31 of that year, provided we pay the dividend in January of the following year. Stockholders may not include in their own income tax returns any of our net operating losses or capital losses.

Capital Gain Distributions

        Distributions designated as net capital gain dividends will be taxable to U.S. stockholders as capital gain income. Such capital gain income will be taxable to U.S. stockholders at a maximum rate of 15% (through 2008) in the case of U.S. stockholders who are individuals and 35% for corporations. Capital gains attributable to the sale of depreciable real property held for more than 12 months are subject to a 25% maximum U.S. federal income tax rate for U.S. stockholders who are individuals to the extent of previously claimed depreciation deductions. U.S. stockholders that are corporations may be required to treat up to 20% of certain capital gain dividends as ordinary income.

Retention of Net Capital Gains

        We may elect to retain, rather than distribute as a capital gain dividend, our net capital gains. If we make this election, we would pay tax on such retained capital gains. In such a case, our stockholders would generally:


Passive Activity Losses and Investment Interest Limitations

        Distributions we make and gain arising from the sale or exchange by a U.S. stockholder of our shares will not be treated as passive activity income. As a result, U.S. stockholders will not be able to apply any "passive losses" against income or gain relating to our stock. Distributions we make, to the extent they do not constitute a return of capital, generally will be treated as investment income for purposes of computing the investment interest limitation but the foregoing rule will not apply to distributions representing dividends to the extent such amounts are taxed at the preferential rates as discussed below unless the U.S. stockholders elect to be taxed on such amounts at a higher rate.

Dispositions of Stock

        If you are a U.S. stockholder and you sell or dispose of your shares of stock, you will recognize gain or loss for U.S. federal income tax purposes in an amount equal to the difference between the amount of cash and the fair market value of any property you receive on the sale or other disposition

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and your adjusted tax basis in the shares of stock. In general, capital gains recognized by individuals and other non-corporate U.S. stockholders upon the sale or disposition of shares of our stock will be subject to a maximum U.S. federal income tax rate of 15% for taxable years through 2008, if the shares are held for more than 12 months, and will be taxed at ordinary income rates (of up to 35% through 2010) if the shares are held for 12 months or less. Gains recognized by U.S. stockholders that are corporations are subject to U.S. federal income tax at a maximum rate of 35%, whether or not classified as long-term capital gains. Capital losses recognized by a U.S. stockholder upon the disposition of our common stock are generally available only to offset capital gain income of the U.S. stockholder but not ordinary income (except in the case of individuals, who may offset up to $3,000 of ordinary income each year). In addition, if you are a U.S. stockholder and you recognize loss upon the sale or other disposition of stock that you have held for six months or less, the loss you recognize will be treated as a long-term capital loss to the extent you received distributions from us which were required to be treated as long-term capital gains.

        If a U.S. stockholder recognizes a loss upon a subsequent disposition of shares of our common stock in an amount that exceeds a prescribed threshold, it is possible that the provisions of recently adopted Treasury regulations involving "reportable transactions" could apply, with a resulting requirement to separately disclose the loss generating transaction to the Internal Revenue Service. While these regulations are directed towards "tax shelters," they are broadly written, and apply to transactions that would not typically be considered tax shelters. In addition, legislative proposals have been introduced in Congress, that, if enacted, would impose significant penalties for failure to comply with these requirements. You should consult your tax advisor concerning any possible disclosure obligation with respect to the receipt or disposition of shares of our common stock, or transactions that might be undertaken directly or indirectly by us. Moreover, you should be aware that we and other participants in transactions involving us (including their advisors) might be subject to disclosure or other requirements pursuant to these regulations.

Backup Withholding

        We report to our U.S. stockholders and the Internal Revenue Service the amount of dividends paid during each calendar year, and the amount of any tax withheld. Under the backup withholding rules, a stockholder may be subject to backup withholding with respect to dividends paid unless the holder is a corporation or comes within other exempt categories and, when required, demonstrates this fact, or provides a taxpayer identification number or social security number, certifies as to no loss of exemption from backup withholding, and otherwise complies with applicable requirements of the backup withholding rules. A U.S. stockholder that does not provide us with his correct taxpayer identification number or social security number may also be subject to penalties imposed by the Internal Revenue Service. Backup withholding is not an additional tax. Any amount paid as backup withholding will be creditable against the stockholder's income tax liability. In addition, we may be required to withhold a portion of capital gain distributions to any stockholders who fail to certify their non-foreign status.

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Taxation of Tax-Exempt Stockholders

        Except as provided below, the Internal Revenue Service has ruled that amounts distributed as dividends by a REIT do not constitute unrelated business taxable income when received by a tax-exempt entity, provided that the shares of the REIT are not otherwise used in an unrelated trade or business. Based on that ruling, provided that a tax-exempt stockholder has not held its shares as "debt financed property" within the meaning of the Internal Revenue Code (i.e., where the acquisition or holding of the property is financed through a borrowing by the tax exempt stockholder), the shares are not otherwise used in a unrelated trade or business, and we do not hold an asset that gives rise to "excess inclusion income" (see "—Taxable Mortgage Pools" and "—Excess Inclusion Income") dividend income on our stock and income from the sale of our stock should not be unrelated business taxable income to a tax-exempt stockholder. We expect to engage in transactions that would result in a portion of our dividend income being considered "excess inclusion income," and accordingly, it is likely that a portion of our dividends received by a tax-exempt stockholder could give rise to unrelated businesses taxable income (See"—Taxation of Tax-Exempt Stockholders; Excess Inclusion Income").

        For tax-exempt stockholders which are social clubs, voluntary employee benefit associations, supplemental unemployment benefit trusts, and qualified group legal services plans exempt from U.S. federal income taxation under Sections 501(c)(7), (c)(9), (c)(17) and (c)(20) of the Internal Revenue Code, respectively, income from an investment in our shares will constitute unrelated business taxable income unless the organization is able to claim properly a deduction for amounts set aside or placed in reserve for certain purposes so as to offset the income generated by its investment in our shares. These prospective investors should consult their tax advisors concerning these "set aside" and reserve requirements.

        Notwithstanding the above, however, a portion of the dividends paid by a "pension-held REIT" may be treated as unrelated business taxable income as to any pension trust which:

        Tax-exempt pension funds that are described in Section 401(a) of the Internal Revenue Code are referred to below as "qualified trusts." A REIT is a "pension held REIT" if:

        The percentage of any REIT dividend treated as unrelated business taxable income is equal to the ratio of:


        A de minimis exception applies where the percentage is less than 5% for any year. As a result of the limitations on the transfer and ownership of stock contained in our Charter, we do not expect to be classified as a "pension-held REIT."

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Excess Inclusion Income:

        A portion of our net income attributable to assets financed through our STARs(SM) program (and, therefore, a portion of the dividends payable by us) may be treated as excess inclusion income from a residual interest in a taxable mortgage pool, which may constitute unrelated business taxable income to a tax-exempt stockholder. (See "—Annual Distribution Requirements; Excess Inclusion Income".) Although we have no plan to enter into additional transactions which generate excess inclusion income, it is possible that we may do so. Prospective stockholders should consult their tax advisor regarding the U.S. federal income tax consequences to them of incurring excess inclusion income.

Taxation of Non-U.S. Stockholders

        The rules governing U.S. federal income taxation of beneficial owners of our stock that are not U.S. stockholders ("Non-U.S. stockholders") are complex and no attempt will be made herein to provide more than a summary of such rules.

        PROSPECTIVE NON-U.S. STOCKHOLDERS SHOULD CONSULT THEIR TAX ADVISOR TO DETERMINE THE IMPACT OF FOREIGN, U.S. FEDERAL, STATE, AND LOCAL INCOME TAX LAWS WITH REGARD TO AN INVESTMENT IN OUR SECURITIES AND OF OUR ELECTION TO BE TAXED AS A REIT INCLUDING ANY REPORTING REQUIREMENTS.

        Distributions to Non-U.S. stockholders that are not attributable to gain from sales or exchanges by us of U.S. real property interests and are not designated by us as capital gain dividends or retained capital gains will be treated as dividends of ordinary income to the extent that they are made out of our current or accumulated earnings and profits. Such distributions will generally be subject to a withholding tax equal to 30% of the distribution unless an applicable tax treaty reduces or eliminates that tax. However, if income from an investment in our stock is treated as effectively connected with the Non-U.S. stockholder's conduct of a U.S. trade or business, the Non-U.S. stockholder generally will be subject to U.S. federal income tax at graduated rates, in the same manner as U.S. stockholders are taxed with respect to such distributions (and also may be subject to the 30% branch profits tax in the case of a Non-U.S. stockholder that is a corporation). We expect to withhold U.S. income tax at the rate of 30% on the gross amount of any distributions made to a Non-U.S. stockholder unless: (1) a lower treaty rate applies and any required form, such as IRS Form W-8BEN, evidencing eligibility for that reduced rate is filed by the Non-U.S. stockholder with us; or (2) the Non-U.S. stockholder files an IRS Form W-8ECI with us claiming that the distribution is effectively connected income.

        Any portion of the dividends paid to Non-U.S. stockholders that is treated as excess inclusion income from a REMIC or a taxable mortgage pool will, pursuant to regulations to be issued by the U.S. Treasury Department, not be eligible for exemption from the 30% withholding tax or a reduced treaty rate. In addition, if Treasury regulations are issued allocating our excess inclusion income from non-REMICs among our stockholders, some percentage of our dividends would not be eligible for exemption from the 30% withholding tax or a reduced treaty withholding tax rate in the hands of Non-U.S. stockholders.

        Distributions in excess of our current and accumulated earnings and profits will not be taxable to a stockholder to the extent that such distributions do not exceed the adjusted basis of the stockholder's stock, but rather will reduce the adjusted basis of such shares. To the extent that distributions in excess of current and accumulated earnings and profits exceed the adjusted basis of a Non-U.S. stockholder's stock, such distributions will give rise to tax liability if the Non-U.S. stockholder would otherwise be subject to tax on any gain from the sale or disposition of its stock, as described below. Because it generally cannot be determined at the time a distribution is made whether or not such distribution will be in excess of current and accumulated earnings and profits, the entire amount of any distribution normally will be subject to withholding at the same rate as a dividend. However, amounts so withheld are refundable to the extent it is subsequently determined that such distribution was, in fact, in excess of our current and accumulated earnings and profits. We are also required to withhold 10% of any

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distribution in excess of our current and accumulated earnings and profits. Consequently, although we intend to withhold at a rate of 30% on the entire amount of any distribution, to the extent that we do not do so, any portion of a distribution not subject to withholding at a rate of 30% will be subject to withholding at a rate of 10%.

        For any year in which we qualify as a REIT, distributions that are attributable to gain from sales or exchanges of a U.S. real property interest, which includes certain interests in U.S. real property, but generally does not include mortgage loans, will be taxed to a Non-U.S. stockholder under the provisions of the Foreign Investment in Real Property Tax Act of 1980 ("FIRPTA"). We hold both assets that constitute U.S. real property interests and assets that do not. To the extent our assets do not constitute U.S. real property interests, distributions by us from the sales of such assets will not be subject to tax under the FIRPTA rules. Under FIRPTA, distributions attributable to gain from sales of U.S. real property interests are taxed to a Non-U.S. stockholder as if such gain were effectively connected with a U.S. business. Non-U.S. stockholders thus would be taxed at the normal capital gain rates applicable to U.S. stockholders (subject to applicable alternative minimum tax and a special alternative minimum tax in the case of nonresident alien individuals). Distributions subject to FIRPTA also may be subject to the 30% branch profits tax in the hands of a Non-U.S. stockholder that is a corporation. However, the 35% withholding tax will not apply to any capital gain dividend with respect to any class of our stock which is regularly traded on an established securities market located in the United States if the non-U.S. stockholder did not own more than 5% of such class of stock at any time during the taxable year. Instead, any capital gain dividend will be treated as a distribution subject to the rules discussed above under "—Taxation of Non-U.S. Stockholders." Also, the branch profits tax will not apply to such a distribution.

        Gain recognized by a Non-U.S. stockholder upon a sale of our stock generally will not be taxed under FIRPTA if we are a "domestically controlled REIT," which is a REIT in which at all times during a specified testing period less than 50% in value of the stock was held directly or indirectly by Non-U.S. persons. Although we currently believe that we are a domestically controlled REIT, because our stock is publicly traded, no assurance can be given that we are or will remain a domestically controlled REIT. Even if we do not qualify as a domestically controlled REIT, an alternative exemption to tax under FIRPTA might be available if either (a) we are not (and have not been for the five year period prior to the sale) a U.S. real property holding corporation (as defined in the Internal Revenue Code and applicable Treasury Regulations to generally include a corporation, 50% or more of the assets of which consist of U.S. real property interests) or (b) the selling Non-U.S. stockholder owns, actually or constructively, 5% or less of our stock throughout a specified testing period and our shares are regularly traded (as defined in applicable Treasury Regulations) on an established securities market. If we did not qualify as a domestically controlled REIT and a Non-U.S. stockholder does not qualify for the above exception, amounts realized by such Non-U.S. stockholder upon a sale of our stock generally would be subject to withholding under FIRPTA at a rate of 10%.

        Gain not subject to FIRPTA will be taxable to a Non-U.S. stockholder if: (1) the Non-U.S. stockholder's investment in the stock is effectively connected with a U.S. trade or business, in which case the Non-U.S. stockholder will be subject to the same treatment as U.S. stockholders with respect to such gain; or (2) the Non-U.S. stockholder is a nonresident alien individual who was present in the U.S. for 183 days or more during the taxable year and other conditions are met, in which case the nonresident alien individual will be subject to a 30% tax on the individual's capital gains. If the gain on the sale of the stock were to be subject to taxation under FIRPTA, the Non-U.S. stockholder would be subject to the same treatment as U.S. stockholders with respect to such gain (subject to applicable alternative minimum tax, a special alternative minimum tax in the case of nonresident alien individuals, and the possible application of the 30% branch profits tax in the case of Non-U.S. corporations).

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State, Local and Foreign Taxation

        We may be required to pay state, local and foreign taxes in various state, local and foreign jurisdictions, including those in which we transact business or make investments, and our stockholders may be required to pay state, local and foreign taxes in various state, local and foreign jurisdictions, including those in which they reside. Our state, local and foreign tax treatment may not conform to the U.S. federal income tax consequences summarized above. In addition, your state, local and foreign tax treatment may not conform to the U.S. federal income tax consequences summarized above. Consequently, you should consult your tax advisor regarding the effect of state, local and foreign tax laws on an investment in our securities.

Possible Legislative or Other Actions Affecting REITs

        The rules dealing with U.S. federal income taxation are constantly under review by persons involved in the legislative process and by the Internal Revenue Service and the U.S. Treasury Department. Changes to the tax law, which may have retroactive application, could adversely affect us and our investors. It cannot be predicted whether, when, in what forms, or with what effective dates, the tax law applicable to us or our investors will be changed.


PLAN OF DISTRIBUTION

        We may sell the securities offered by this prospectus to one or more underwriters for public offering and sale by them or we may sell the securities to investors directly or through agents. Any underwriter or agent involved in the offer and sale of the securities will be named in the applicable prospectus supplement.

        Underwriters may offer and sell the securities at a fixed price or prices, which may be changed, related to the prevailing market prices at the time of sale or at negotiated prices. We also may, from time to time, authorize underwriters acting as agents to offer and sell the securities to purchasers upon the terms and conditions set forth in the applicable prospectus supplement. In connection with the sale of securities, underwriters may be deemed to have received compensation from us in the form of underwriting discounts or commissions and may also receive commissions from purchasers of securities for whom they may act as agent. Underwriters may sell securities to or through dealers, and the dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters and/or commissions from the purchasers for whom they may act as agent.

        Securities may also be sold in one or more of the following transactions: (a) block transactions (which may involve crosses) in which a broker-dealer may sell all or a portion of the securities as agent but may position and resell all or a portion of the block as principal to facilitate the transaction; (b) purchases by a broker-dealer as principal and resale by the broker-dealer for its own account pursuant to a prospectus supplement; (c) a special offering, an exchange distribution or a secondary distribution in accordance with applicable New York Stock Exchange or other stock exchange rules; (d) ordinary brokerage transactions and transactions in which a broker-dealer solicits purchasers; (e) sales "at the market" to or through a market maker or into an existing trading market, on an exchange or otherwise, for shares; and (f) sales in other ways not involving market makers or established trading markets, including direct sales to purchasers. Broker-dealers may also receive compensation from purchasers of these securities which is not expected to exceed that customary in the types of transactions involved.

        Any underwriting compensation paid by us to underwriters or agents in connection with the offering of securities, and any discounts, concessions or commissions allowed by underwriters to participating dealers, will be set forth in the applicable prospectus supplement. Underwriters, dealers and agents participating in the distribution of the securities may be deemed to be underwriters, and any discounts and commissions received by them and any profit realized by them on resale of the securities may be deemed to be underwriting discounts and commissions, under the Securities Act of 1933, as

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amended. Underwriters, dealers and agents may be entitled, under agreements entered into with us and our operating partnership, to indemnification against and contribution toward civil liabilities, including liabilities under the Securities Act of 1933, as amended.

        Any securities issued hereunder (other than common stock) will be new issues of securities with no established trading market. Any underwriters or agents to or through whom such securities are sold by us or the operating partnership for public offering and sale may make a market in such securities, but such underwriters or agents will not be obligated to do so and may discontinue any market making at any time without notice. We cannot assure you as to the liquidity of the trading market for any such securities.

        In connection with the offering of the securities described in this prospectus and an accompanying prospectus supplement, certain underwriters and selling group members and their respective affiliates, may engage in transactions that stabilize, maintain or otherwise affect the market price of the security being offered. These transactions may include stabilization transactions effected in accordance with Rule 104 of Regulation M promulgated by the SEC pursuant to which these persons may bid for or purchase securities for the purpose of stabilizing their market price.

        The underwriters in an offering of these securities may also create a "short position" for their account by selling more equity securities or a larger principal amount of debt securities in connection with the offering than they are committed to purchase from us. In that case, the underwriters could cover all or a portion of the short position by either purchasing the securities in the open market following completion of the offering or by exercising any over-allotment option granted to them by us. In addition, the managing underwriter may impose "penalty bids" under contractual arrangements with other underwriters, which means that they can reclaim from an underwriter (or any selling group member participating in the offering) for the account of the other underwriters, the selling concession for the securities that is distributed in the offering but subsequently purchased for the account of the underwriters in the open market. Any of the transactions described in this paragraph or comparable transactions that are described in any accompanying prospectus supplement may result in the maintenance of the price of our securities at a level above that which might otherwise prevail in the open market. None of the transactions described in this paragraph or in an accompanying prospectus supplement are required to be taken by any underwriters and, if they are undertaken, may be discontinued at any time.

        Any underwriters and their affiliates may be customers of, engage in transactions with and perform services for us and the operating partnership and its subsidiaries in the ordinary course of business.


LEGAL MATTERS

        Clifford Chance US LLP, 31 West 52nd Street, New York, New York 10019, will pass upon the validity of the securities we are offering by this prospectus. If the validity of any securities is also passed upon by counsel for the underwriters of an offering of those securities, that counsel will be named in the prospectus supplement relating to that offering. Clifford Chance US LLP will rely upon the opinion of Venable LLP with respect to certain matters of Maryland law.


EXPERTS

        The financial statements and management's assessment of the effectiveness of internal control over financial reporting (which is included in Management's Report on Internal Control over Financial Reporting) incorporated in this Registration Statement by reference to the Annual Report on Form 10-K for the year ended December 31, 2004 have been so incorporated in reliance on the report of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

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INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

        We are incorporating by reference in this prospectus the following documents which we have previously filed with the Securities and Exchange Commission under the File Number 1-10150:

        Whenever after the date of this prospectus we file reports or documents under Section 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended, those reports and documents will be deemed to be part of this prospectus from the time they are filed. If anything in a report or document we file after the date of this prospectus changes anything in it, this prospectus will be deemed to be changed by that subsequently filed report or document beginning on the date the report or document is filed.

        We will provide to each person to whom a copy of this prospectus is delivered a copy of any or all of the information that has been incorporated by reference in this prospectus, but not delivered with this prospectus. We will provide this information at no cost to the requestor upon written or oral request addressed to iStar Financial Inc., 1114 Avenue of the Americas, New York, New York 10036, attention: Investor Relations Department (Telephone: (212) 930-9400).


INFORMATION WE FILE

        We file annual, quarterly and current reports, proxy statements and other materials with the SEC. The public may read and copy any materials we file with the SEC at the SEC's Public Reference Room at 450 Fifth Street, N.W., Washington, D.C. 20549. The public may obtain information on the operation of the Public Reference Room by calling the SEC at 1-800-SEC-0330. The SEC maintains an Internet site that contains reports, proxy and information statements and other information regarding issuers (including us) that file electronically with the SEC. The address of that site is http://www.sec.gov.

        Reports, proxy statements and other information we file also can be inspected at the offices of the New York Stock Exchange, 20 Broad Street, New York, New York 10005.

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$475,000,000

GRAPHIC

$250,000,000 5.80% Senior Notes due 2011

$225,000,000 Senior Floating Rate Notes due 2009

Joint Book-Running Managers

Merrill Lynch & Co.
UBS Investment Bank

Co-Managers

HSBC
RBC Capital Markets
Scotia Capital

Prospectus Supplement

December 7, 2005



QuickLinks

TABLE OF CONTENTS
Creative Capital Solutions and the iStar Financial logo are registered trade marks of iStar Financial Inc.
FORWARD-LOOKING STATEMENTS
Summary
iSTAR FINANCIAL INC.
RISK FACTORS
RATIO OF EARNINGS TO FIXED CHARGES
USE OF PROCEEDS
DESCRIPTION OF OTHER INDEBTEDNESS
DESCRIPTION OF THE NOTES
CERTAIN U.S. FEDERAL INCOME TAX CONSEQUENCES
UNDERWRITING
LEGAL MATTERS
EXPERTS
TABLE OF CONTENTS
ABOUT THIS PROSPECTUS
FORWARD-LOOKING STATEMENTS
iSTAR FINANCIAL INC.
RISK FACTORS
RATIOS OF EARNINGS TO COMBINED FIXED CHARGES AND PREFERRED STOCK DIVIDENDS AND EARNINGS TO FIXED CHARGES
USE OF PROCEEDS
DESCRIPTION OF DEBT SECURITIES
DESCRIPTION OF WARRANTS
DESCRIPTION OF COMMON STOCK AND PREFERRED STOCK
DESCRIPTION OF DEPOSITARY SHARES
CERTAIN U.S. FEDERAL INCOME TAX CONSEQUENCES
PLAN OF DISTRIBUTION
LEGAL MATTERS
EXPERTS
INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE
INFORMATION WE FILE