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

OMB APPROVAL OMB Number: 3235-0287 Expires: January 31, 2005 Estimated average burden hours per response... 0.5

(Print or Type Responses)

1. Name and Address of Reporting Person * WARBURG PINCUS PRIVATE EQUITY VIII L P   2. Issuer Name and Ticker or Trading Symbol DEXCOM INC [DXCM] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 466 LEXINGTON AVENUE,  3. Date of Earliest Transaction (Month/Day/Year) 07/21/2005 (Street) NEW YORK, NY 10017 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) ___ Form filed by One Reporting Person _X_ 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               2,609,267 I See Footnote (1) Common Stock               44,371 I See Footnote (1) Common Stock               31,259 I See Footnote (1) Common Stock               7,565 I See Footnote (1) Common Stock 07/21/2005   A V 89 A $ 11.25 89 I See Footnote (2) Common Stock 07/29/2005   A V 91 A $ 11.02 180 I See Footnote (2) Common Stock 08/08/2005   A V 97 A $ 10.39 277 I See Footnote (2)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
	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 control number.		SEC 1474 (9-02)

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
WARBURG PINCUS PRIVATE EQUITY VIII L P 466 LEXINGTON AVENUE NEW YORK, NY 10017		X
WARBURG PINCUS & CO 466 LEXINGTON AVENUE NEW YORK NY, NY 100173147		X
Warburg Pincus Partners LLC 466 LEXINGTON AVENUE NEW YORK, NY 10017		X
WARBURG PINCUS LLC 466 LEXINGTON AVENUE NEW YORK, NY 10017		X

Signatures

Warburg Pincus Private Equity VIII, L.P. By: Warburg Pincus Partners LLC, its General Partner By: Warburg Pincus & Co., its Managing Member By: /s/ Sean Carney, Partner		08/12/2005
**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)	The stockholder is Warburg Pincus Private Equity VIII, L.P., a Delaware limited partnership, including two affiliated partnerships (collectively "WP VIII"). Warburg Pincus Partners LLC ("WP Partners LLC"), a New York limited liability company, a subsidiary of Warburg Pincus & Co. ("WP"), a New York general partnership, is the sole general partner of WP VIII. Warburg Pincus LLC ("WP LLC"), a New York limited liability company, manages WP VIII. By reason of the provisions of Rule 16a-1 of the Securities Exchange Act of 1934, as amended, WP VIII, WP Partners LLC, WP and WP LLC may be deemed to be the beneficial owners of the referenced shares. WP Partners LLC, WP and WP LLC disclaim beneficial ownership of such securities, except to the extent of any indirect pecuniary interest therein.
(2)	The stockholder is Sean D. Carney. Mr. Carney is a member of the board of directors of the Issuer, a partner of WP and a member and managing director of WP LLC. WP VIII, WP Partners LLC, WP and WP LLC disclaim beneficial ownership of such securities, except to the extent of any indirect pecuniary interest therein.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.