DEXCOM INC — Director's Dealing 2012

Apr 5, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: DEXCOM INC (DXCM)
CIK: 0001093557
Period of Report: 2012-04-03

Reporting Person: GREGG TERRANCE H (Director, CEO)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-04-03	Common Stock	S	5000	$10.6351	Disposed	984889	Indirect

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	30000	Direct
Common Stock	11461	Indirect

Footnotes

F1: On November 21, 2011, Mr. Gregg adopted a 10b5-1 Plan. Under the 10b5-1 Plan, Mr. Gregg will sell a limited number of shares to cover the tax liability that accrues upon monthly vesting of restricted stock units previously granted to Mr. Gregg. The shares set forth above were sold pursuant to the 10b5-1 Plan.

F2: This transaction was executed in multiple trades at prices ranging from $10.59 to $10.67. The price above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issurer full information regarding the number of shares and prices at which the transactions were effected.

F3: Included in this number are 146,250 restricted stock units subject to vesting with respect to 1/36 of the units each month beginning one month following the grant date of March 12, 2010. Also included in this number are 182,813 restricted stock units subject to vesting with respect to 1/36 of the units each month beginning one month following the grant date of March 8, 2011. Also included in this number are 182,813 restricted stock units subject to vesting with respect to 1/36 of the units each month beginning one month following the grant date of March 8, 2012.

F4: Shares are held by the Gregg Family Trust U/A/D 12/23/1998, with respect to which the reporting person is a trustee.