X0306 4 2013-06-06 0 0001020569 IRON MOUNTAIN INC IRM 0001244482 ANTENUCCI TED R C/O IRON MOUNTAIN INCORPORATED 745 ATLANTIC AVENUE BOSTON MA 02111 1 0 0 0 Phantom Stock 2013-06-06 4 A 0 3953 0.01 A Common Stock 3953 8142 D Phantom Stock 2013-06-06 4 A 0 218.3949 33.9414 A Common Stock 218.3949 8360.3949 D Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan with respect to certain restricted stock units ("RSUs") received on June 6, 2013, which RSUs shall vest on the one year anniversary of the grant date (or, if earlier, the annual meeting of stockholders that is closest to the one year anniversary), the shares of phantom stock (the "Phantom Shares") become payable in Iron Mountain Incorporated common stock on various dates selected by the Reporting Person or as otherwise provided in the Iron Mountain Incorporated Directors Deferred Compensation Plan. Each Phantom Share is the economic equivalent of one share of common stock. Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the Phantom Shares become payable in shares of common stock on various dates selected by the Reporting Person or as otherwise provided in the Iron Mountain Incorporated Directors Deferred Compensation Plan. Each Phantom Share is the economic equivalent of one share of common stock. These shares give effect to dividends paid on previously reported restricted stock units as if reinvested in Phantom Shares. /s/ Sarah Cammarata, under Power of Attorney dated June 21, 2011, from Ted Antenucci 2013-06-10