SEC FORM 3

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person^*

LUCAS DONALD L

(Last)

(First)

(Middle)

SANDHILL FINANCIAL COMPANY

3000 SANDHILL ROAD, BUILDING 3-210

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
04/13/2005

3. Issuer Name and Ticker or Trading Symbol
DEXCOM INC [ DXCM ]

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	10% Owner
	Officer (give title below)	Other (specify below)

5. If Amendment, Date of 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

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	87,500	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivative Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
Stock Option (Right to Buy)	⁽¹⁾	01/29/2013	Common Stock	62,500	$0.5	D
Stock Option (Right to Buy)	⁽²⁾	03/10/2014	Common Stock	12,500	$0.5	D
Series C Preferred Stock	⁽³⁾	⁽⁴⁾	Common Stock	86,956	⁽³⁾	I	By the Donald L. Lucas Profit Sharing Trust⁽⁵⁾
Series D Preferred Stock	⁽³⁾	⁽⁴⁾	Common Stock	8,706	⁽³⁾	I	By the Donald L. Lucas Profit Sharing Trust⁽⁵⁾
Series C Preferred Stock	⁽³⁾	⁽⁴⁾	Common Stock	130,435	⁽³⁾	I	By the Donald L. Lucas & Lygia S. Lucas Trust U/T/D 12/3/84⁽⁶⁾
Series D Preferred Stock	⁽³⁾	⁽⁴⁾	Common Stock	13,059	⁽³⁾	I	By the Donald L. Lucas & Lygia S. Lucas Trust U/T/D 12/3/84⁽⁶⁾
Series C Preferred Stock	⁽³⁾	⁽⁴⁾	Common Stock	108,695	⁽³⁾	I	By Sand Hill Corporation⁽⁷⁾
Series D Preferred Stock	⁽³⁾	⁽⁴⁾	Common Stock	7,449	⁽³⁾	I	By Sand Hill Corporation⁽⁷⁾

Explanation of Responses:

1. The option vests and becomes exercisable in pro rata monthly installments through October 21, 2006.

2. The option vests and becomes exercisable over a period of four years in equal monthly installments beginning the month following the vesting commencement date of March 4, 2004.

3. Each share of preferred stock is convertible into 0.5 shares of the Issuers Common Stock and will convert automatically 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.

4. Not Applicable

5. Shares are held by Donald L. Lucas Profit Sharing Trust, which the Reporting Person is a Trustee.

6. Shares are held by Donald L. Lucas, TTEE, Donald L. Lucas & Lygia S. Lucas Trust, Dated 12/03/84, which the Reporting Person is a Trustee.

7. Mr. Lucas is a general partner of Sand Hill Financial Corporation ("Sand Hill") and disclaims beneficial ownership of shares held by Sand Hill. The reporting person disclaims beneficial ownership of these shares except to his pecuniary interest therein.

	Donald L. Lucas	04/13/2005
	** Signature of Reporting Person	Date
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 5 (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.
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