Tax Basis Reporting Under Internal Revenue Code § 6045B

Pursuant to the Internal Revenue Code § 6045B, effective January 1, 2011, issuers of corporate stock must report corporate actions affecting stock basis, including but not limited to mergers, spin-offs, stock-splits, stock redemptions and distributions in excess of corporate earnings and profits.

American Tower American Tower Corporation is providing the following information with respect to its merger as part of its conversion to a real estate investment trust effective December 31, 2011. Although we do not believe that the merger affected the basis of our stock, we are providing this Form to ensure our compliance with these requirements.

2011 Reporting – Form 8937

American Tower Corporation is providing the following information with respect to an adjustment to the conversion rates for its 5.25% Mandatory Convertible Preferred Stock, Series A (the “Series A Preferred Stock”).  The adjustment to the conversion rates was made pursuant to the Certificate of Designations establishing the Series A Preferred Stock (the “Certificate of Designations”) in light of American Tower’s previously announced second quarter 2016 common stock cash dividend of $0.53 per common share and recognition of carried-forward adjustments relating to common stock cash dividends paid on July 16, 2014, October 7, 2014, January 13, 2015, April 28, 2015, July 16, 2015, October 7, 2015, January 13, 2016, and April 28, 2016, which adjustments were deferred and carried forward as permitted under the Certificate of Designations. 

2016 Reporting – Form 8937

American Tower Corporation (NYSE: AMT) announced an adjustment to the conversion rates for its 5.50% Mandatory Convertible Preferred Stock, Series B (the "Series B Preferred Stock"). The adjustment to the conversion rates was made pursuant to the Certificate of Designations establishing the Series B Preferred Stock (the "Certificate of Designations") in light of American Tower’s previously announced first quarter 2017 common stock cash dividend of $0.62 per common share and recognition of carried-forward adjustments relating to common stock cash dividends paid on April 28, 2015, July 16, 2015, October 7, 2015, January 13, 2016, April 28, 2016, July 15, 2016, October 17, 2016, and January 13, 2017, which adjustments were deferred and carried forward as permitted under the Certificate of Designations.

2017 Reporting – Form 8937 Series B

American Tower Corporation is providing the following information with respect to an adjustment to the conversion rates for its 5.25% Mandatory Convertible Preferred Stock, Series A (the "Series A Preferred Stock"). The adjustment to the conversion rates was made pursuant to the Certificate of Designations establishing the Series A Preferred Stock (the &qout;Certificate of Designations") in light of an early conversion that occurred on April 27, 2017 and recognition of carried-forward adjustments relating to common stock cash dividends paid on October 17, 2016, January 13, 2017, and April 28, 2017, which adjustments were deferred and carried forward as permitted under the Certificate of Designations.

2017 Reporting – Form 8937 Series A

Form 8937 – Preferred Series B Anti-Dilution

For additional information on Internal Revenue Code § 6045B, please visit the IRS website at www.irs.gov and consult with your tax advisor on all tax-related inquiries.

Contact Us

Investor Relations
Igor Khislavsky: Vice President, Investor Relations
investor.relations@americantower.com

Corporate Headquarters
American Tower Corporation
116 Huntington Ave. 11th Floor, Boston, MA 02116
617-375-7500  |  617-375-7575 fax

Transfer Agent
Computershare
P.O. Box 505000, Louisville, KY 40233
866-201-5087  |  781-575-2879