X0306 4 2015-06-26 0 0001020569 IRON MOUNTAIN INC IRM 0001183331 BAILEY CLARK H 10 OXFORD ROAD LARCHMONT NY 10538 1 0 0 0 Phantom Stock 2015-06-26 4 A 0 337.6346 32.5791 A Common Stock 337.6346 23495.1744 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 following the Reporting Person's disability or cessation of service as a director. 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 September 16, 2010, from Clarke H. Bailey 2015-06-30