are types of securities that we may offer, issue and sell from time to time, or that may be sold by selling securityholders from time to time, together or separately:
shares of our common stock;
shares of our preferred stock;
warrants to purchase debt or equity securities;
purchase contracts; and
Any of these securities may be offered together or separately and in one or more series, if any, in amounts, at prices and on other terms
to be determined at the time of the offering and described in an accompanying prospectus supplement. You should read this prospectus and any prospectus supplement carefully before you invest.
Unless otherwise stated in a prospectus supplement, none of these securities other than our common stock will be listed on any securities
exchange. Our common stock is listed on the New York Stock Exchange under the symbol AMT.
We may offer and sell
these securities through one or more underwriters, dealers or agents, through underwriting syndicates managed or co-managed by one or more underwriters, or directly to purchasers, on a continuous or delayed basis. The prospectus supplement for each
offering of securities will describe in detail the plan of distribution for that offering.
To the extent that any selling
securityholder resells any securities, the selling securityholder may be required to provide you with this prospectus and a prospectus supplement identifying and containing specific information about the selling securityholder and the terms of the
securities being offered.
Investing in the offered securities involves risks. You should consider the risk factors
described in any applicable prospectus supplement and in the documents we incorporate by reference.
Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the accuracy or adequacy of this prospectus or any applicable prospectus supplement. Any representation to the
contrary is a criminal offense.
Prospectus dated June 3, 2016