Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
GREGG TERRANCE H
   2. Issuer Name and Ticker or Trading Symbol
DEXCOM INC [DXCM] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Executive Chairman
(Last)
(First)
(Middle)
6340 SEQUENCE DRIVE		 3. Date of Earliest Transaction (Month/Day/Year)
04/30/2015
(Street)

SAN DIEGO, CA 92121		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 05/04/2015   M   20,000 A $ 8.95 450,626 D  
Common Stock 05/04/2015   S   20,000 D $ 68.0638 (1) 430,626 (2) D  
Common Stock 04/30/2015   S(3)   14,250 D $ 67.13 (3) 522,139 I by Trust (4)
Common Stock               11,461 I by IRA

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Non-Qualified Stock Option (right to buy) $ 8.95 05/04/2015   M     20,000 01/02/2009 01/02/2018 Common Stock 20,000 $ 68.0638 20,000 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
GREGG TERRANCE H
6340 SEQUENCE DRIVE
SAN DIEGO, CA 92121		   X     Executive Chairman  

Signatures

 By: Jess Roper For: Terrance H. Gregg   05/04/2015
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) This transaction was executed in multiple trades at prices ranging from $68.02 to $68.13. The price above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transactions were effected.
(2) Included in this number are 207,658 unvested restricted stock units, 35,000 of which were granted on March 8, 2015 and will vest on March 8, 2016, 116,798 unvested restricted stock units granted on March 8, 2014, 5,078 of which shall vest each month through March 8, 2017, and 55,860 unvested restricted stock units granted on March 11, 2013, 5,078 of which shall vest each month through March 11, 2016.
(3) The reporting person contributed Dexcom, Inc. Common Stock to an exchange fund, pursuant to an agreement dated March 5, 2015 to contribute shares of DexCom, Inc. Common Stock in exchange for shares of the exchange fund. The Dexcom, Inc. Common Stock was valued at $67.13 per share for the purposes of determining the number of shares of the exchange fund issuable to the reporting person with respect to the April 30, 2015 closing of the exchange fund.
(4) Shares are held by the Gregg Family Trust U/A/D 12/23/1998, with respect to which the reporting person is a trustee.

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