DEXCOM INC — Director's Dealing 2012

Mar 13, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: DEXCOM INC (DXCM)
CIK: 0001093557
Period of Report: 2012-03-08

Reporting Person: LISTER JOHN (VP of Legal Affairs)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-03-08	Common Stock	A	33125	$0.001000	Acquired	60250	Direct
2012-03-08	Common Stock	D	3438	$10.258300	Disposed	56812	Direct

Footnotes

F1: Represents a grant of restricted stock units that are exempt from Section 16 b-3 and are subject to vesting over a 36 month period from the date of grant as follows: 1/3 shall vest 12 months from the Grant Date, and the remaining balance shall vest in four equal installments over the following 24 months. Share units represent a contingent right to receive one share of DexCom, Inc. common stock.

F2: 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.

F3: Included in this number are 25,625 restricted stock units subject to vesting over a 36 month period following the grant date of March 8, 2011 as follows: 1/3 shall vest 12 months from the Grant Date, and the remaining balance shall vest in four equal installments over the following 24 months.