AMERICAN TOWER CORP /MA/ — Director's Dealing 2012

Apr 3, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AMERICAN TOWER CORP /MA/ (AMT)
CIK: 0001053507
Period of Report: 2012-04-01

Reporting Person: Bartlett Thomas A (EVP, CFO & Treasurer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-04-01	Common Stock	M	9908	—	Acquired	17071	Direct
2012-04-01	Common Stock	F	4137	$63.02	Disposed	12934	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-04-01	Restricted Stock Units	$	M	9908	Disposed		Common Stock (9908)	Direct

Footnotes

F1: Each Restricted Stock Unit (RSU) respresents a contingent right to receive one share of Common Stock.

F2: This RSU was granted on April 1, 2009 pursuant to the 2007 Equity Incentive Plan, and vests in 25% cumulative annual increments beginning April 1, 2010. This Form 4 reflects the vesting of this RSU on April 1, 2012 as to 75% of the original grant amount.