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)
09/09/2016
(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 09/09/2016   D   2,203 (1) D $ 93.7226 449,283 (2) D  
Common Stock               11,461 I by IRA
Common Stock               65,882 I by Trust (3)

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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

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: Kevin Sun For: Terrance H. Gregg   09/13/2016
**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) These shares were sold to cover the Company's tax withholding obligation that accrued in connection with the vesting of restricted stock units previously granted.
(2) Included in this number are 64,469 unvested restricted stock units, 34,000 of which were granted on March 8, 2016 and will vest on March 8, 2017 and 30,469 unvested restricted stock units granted on March 8, 2014, 5,078 of which shall vest each month through March 8, 2017.
(3) Shares are held by the Gregg Family Trust U/A/D 12/23/1998, with respect to which the reporting person is a trustee.
 
Remarks:
CONFIRMING STATEMENT: This Statement confirms that the undersigned Terrance Gregg, has authorized and designated Steve Pacelli, Jess Roper, Kevin Sun, Patrick Murphy and Timothy O'Brien to execute and file on the undersigned's behalf all Forms 3, 4, and 5 (including any amendments thereto) that the undersigned may be required to file with the U.S. Securities and Exchange Commission as a result of the undersigned's ownership of or transactions in securities of DexCom, Inc. The authority of Steve Pacelli, Jess Roper, Kevin Sun, Patrick Murphy and Timothy O'Brien under this Statement shall continue until the undersigned is no longer required to file Forms 3, 4, and 5 with regard to the undersigned's ownership of or transactions in securities of DexCom, Inc., unless earlier revoked in writing. The undersigned acknowledges that Steve Pacelli, Jess Roper, Kevin Sun, Patrick Murphy and Timothy O'Brien are not assuming any of the undersigned's responsibilities to comply with Section 16 of the Securities Exchange Act of 1934. Date: September 9, 2016 /s/ TERRANCE GREGG Terrance Gregg

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