X0306 4 2015-06-26 0 0001020569 IRON MOUNTAIN INC IRM 0001244482 ANTENUCCI TED R C/O IRON MOUNTAIN INCORPORATED ONE FEDERAL STREET BOSTON MA 02110 1 0 0 0 Phantom Stock 2015-06-26 4 A 0 274.1665 32.5791 A Common Stock 274.1665 19078.5818 D Pursuant to the Reporting Person's election to participate in the Iron Mountain Incorporated Directors Deferred Compensation Plan, the shares of phantom stock (the "Phantom Shares") will become payable in shares of 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. These shares give effect to dividends paid on common stock as if reinvested in Phantom Shares. /s/ Garry B. Watzke, under Power of Attorney dated June 21, 2011, from Ted Antenucci 2015-06-30