X0304 4/A 2011-09-08 2011-09-12 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 9012 D Restricted Stock Units 2011-09-08 4 A 0 15358 0 A Common Stock 15358 15358 D On September 12, 2011, the reporting person filed a Form 4 reporting an acquisition of 15,358 shares of Iron Mountain Incorporated common stock that reflected the grant to the reporting person by Iron Mountain Incorporated of restricted stock units ("RSUs"). For ease of reporting, the original Form 4 is being amended for the sole purpose of reflecting the grant of such RSUs in Table II. As of September 8, 2011, the reporting person owned only 9,012 shares of Iron Mountain Incorporated common stock, which includes 521 shares acquired under the Iron Mountain Incorporated Employee Stock Purchase Plan since the most recent Section 16 filing prior to September 8, 2011 by the reporting person. The reporting person's original Form 4 disclosed the grant of RSUs in Table I; for ease of reporting, the original Form 4 is being amended for the sole purpose of reflecting the grant of such RSUs in Table II. The number of RSUs granted and the vesting schedule of the RSUs has not changed. Each RSU represents a contingent right to receive one share of Iron Mountain Incorporated common stock. The RSUs vest 50% on second anniversary of the date of grant, 25% on the third anniversary of the date of grant and 25% on the fourth anniversary of the date of grant. /s/ Sarah Cammarata, under Power of Attorney dated November 17, 2010, from Harold E. Ebbighausen 2012-03-13