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 *
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)
04/19/2005
(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 04/19/2005   C   2,609,267 A (1) 2,609,267 I See Footnote (3)
Common Stock 04/19/2005   C   44,371 A (1) 44,371 I See Footnote (3)
Common Stock 04/19/2005   C   31,259 A (1) 31,259 I See Footnote (3)
Common Stock 04/19/2005   C   7,565 A (1) 7,565 I See Footnote (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
Series D Preferred Stock (1) 04/19/2005   C     5,218,535   (1)   (2) Common Stock 2,609,267 (1) (1) 0 I See Footnote (3)
Series D Preferred Stock (1) 04/18/2005   C     88,743   (1)   (2) Common Stock 44,371 (1) (1) 0 I See Footnote (3)
Series D Preferred Stock (1) 04/19/2005   C     62,159   (1)   (2) Common Stock 31,259 (1) (1) 0 I See Footnote (3)
Series D Preferred Stock (1) 04/19/2005   C     15,131   (1)   (2) Common Stock 7,565 (1) (1) 0 I See Footnote (3)

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:Scott A. Arenare, Partner   04/19/2005
**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) Each share converted automatically into 0.5 shares of the Issuers Common Stock upon the closing of the Issuers initial public offering of Common Stock pursuant to an effective registration statement filed with the U.S. Securities and Exchange Commission.
(2) Not Applicable
(3) 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.
 
Remarks:
See Exhibit 99.1 - Joint Filer Information

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