AMERICAN TOWER CORP /MA/ — Director's Dealing 2013

Mar 12, 2013

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AMERICAN TOWER CORP /MA/ (AMT)
CIK: 0001053507
Period of Report: 2013-03-10

Reporting Person: Marshall Steven C. (EVP & President, U.S. Tower)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2013-03-10	Common Stock	M	5283	—	Acquired	8693	Direct
2013-03-10	Common Stock	F	1897	$77.14	Disposed	6796	Direct
2013-03-10	Common Stock	M	5219	—	Acquired	12015	Direct
2013-03-10	Common Stock	F	2446	$77.14	Disposed	9569	Direct
2013-03-10	Common Stock	M	5170	—	Acquired	14739	Direct
2013-03-10	Common Stock	F	2423	$77.14	Disposed	12316	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2013-03-10	Restricted Stock Units	$	M	5283	Disposed		Common Stock (5283)	Direct
2013-03-10	Restricted Stock Units	$	M	5219	Disposed		Common Stock (5219)	Direct
2013-03-10	Restricted Stock Units	$	M	5170	Disposed		Common Stock (5170)	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 March 10, 2009 pursuant to the 2007 Equity Incentive Plan, and vests in 25% cumulative annual increments beginning March 10, 2010. This Form 4 reflects the vesting of this RSU on March 10, 2013 as to 100% of the original grant amount.

F3: This RSU was granted on March 10, 2010 pursuant to the 2007 Equity Incentive Plan, and vests in 25% cumulative annual increments beginning March 10, 2011. This Form 4 reflects the vesting of this RSU on March 10, 2013 as to 75% of the original grant amount.

F4: This RSU was granted on March 10, 2011 pursuant to the 2007 Equity Incentive Plan, and vests in 25% cumulative annual increments beginning March 10, 2012. This Form 4 reflects the vesting of this RSU on March 10, 2013 as to 50% of the original grant amount.