Sec Form 4 Filing - SAYER KEVIN R @ DEXCOM INC - 2016-09-09

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 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

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person SAYER KEVIN R 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) President & CEO (Last) (First) (Middle) 6340 SEQUENCE DRIVE 3. Date of Earliest Transaction (MM/DD/YY) 09/09/2016 (Street) SAN DIEGO, CA92121 4. If Amendment, Date Original Filed (MM/DD/YY) 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 8,001 ( 1 ) D $ 93.7226 327,226 ( 2 ) D Common Stock 09/09/2016 D 13,335 ( 1 ) D $ 93.7226 313,891 ( 2 ) D

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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 SAYER KEVIN R 6340 SEQUENCE DRIVE SAN DIEGO, CA92121 X President & CEO Signatures By: Kevin Sun For: Kevin R. Sayer 09/13/2016 Signature of Reporting Person Date

Explanation of Responses:

( 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 160,000 unvested restricted stock units, 90,000 of which were granted on March 8, 2016 and shall vest through March 8, 2019, 45,000 of which were granted on March 8, 2015 and shall vest through March 8, 2018 and 25,000 of which were granted on March 8, 2014 and shall vest through March 8, 2017.

Remarks: CONFIRMING STATEMENT: This Statement confirms that the undersigned Kevin Sayer, 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: August 24, 2016 /s/ KEVIN SAYER Kevin Sayer

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* 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).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.