X0306 4 2013-09-09 0 0001020569 IRON MOUNTAIN INC IRM 0001183335 EBBIGHAUSEN HAROLD E 6 EDMUND BRIGHAM WAY WESTBOROUGH MA 01581 0 1 0 0 President, North America Common Stock, par value $.01 per share 2013-09-09 4 A 0 8438 0 A 45705 D Common Stock, par value $.01 per share 2013-09-09 4 F 0 3756 26.08 D 41949 D Restricted Stock Units 2013-09-09 4 D 0 8438 0 D Common Stock 8438 8438 D This acquisition is reported to reflect the partial vesting of restricted stock units ("RSUs") previously granted to the Reporting Person. Includes 792 shares acquired under the Iron Mountain Incorporated Employee Stock Purchase Plan since the last Section 16 filing by the Reporting Person. Each RSU represents a contingent right to receive one share of Iron Mountain Incorporated common stock ("Common Stock"). The RSUs, representing a contingent right to receive a total of 16,876 shares of Common Stock, were granted to the Reporting Person on September 8, 2011. The RSUs vested 50% on the second anniversary of the grant date and the remaining RSUs will vest 25% on the third anniversary of the grant date and 25% on the fourth anniversary of the grant date. The number of RSUs granted includes previously reported RSUs allocated on November 21, 2012 in connection with the Reporting Person's receipt of his pro rata portion of a special dividend declared by the Board of Directors of Iron Mountain Incorporated on October 11, 2012 and paid on November 21, 2012. /s/ Sarah Cammarata, under Power of Attorney dated November 17, 2010, from Harold E. Ebbighausen 2013-09-11