X0306 4 2018-02-15 0 0001020569 IRON MOUNTAIN INC IRM 0001401237 Evens Deirdre C/O IRON MOUNTAIN INCORPORATED ONE FEDERAL STREET BOSTON MA 02110 0 1 0 0 EVP and Chief of Operations Common Stock, par value $.01 per share 2018-02-16 4 M 0 1754 0 A 16371 D Common Stock, par value $.01 per share 2018-02-16 4 F 0 609 33.17 D 15762 D Employee Stock Option (Right to Buy) 33.72 2018-02-15 4 A 0 29037 0 A 2028-02-15 Common Stock 29037 29037 D Restricted Stock Units 2018-02-15 4 A 0 6227 0 A Common Stock 6227 6227 D Restricted Stock Units 2018-02-16 4 M 0 1754 0 D Common Stock 1754 3516 D This acquisition is reported to reflect the partial vesting of restricted stock units ("RSUs") previously granted to the Reporting Person on February 16, 2017. This stock option becomes exercisable in three substantially equal annual installments beginning on the first anniversary of the grant date. Each RSU represents a contingent right to receive one share of Iron Mountain Incorporated common stock ("Common Stock"). The RSUs vest in three substantially equal annual installments beginning on the first anniversary of the grant date. The RSUs, representing a contingent right to receive a total of 5,270 shares of Common Stock, were granted to the Reporting Person on February 16, 217 and vest in three substantially equal annual installments beginning on the first anniversary of the grant date. /s/ Elizabeth Tammaro, under Power of Attorney dated May 26, 2016, from Deirdre Evens 2018-02-20