X0206 3 2017-10-17 0 0001020569 IRON MOUNTAIN INC IRM 0001720656 Borges Daniel C/O IRON MOUNTAIN INCORPORATED ONE FEDERAL STREET BOSTON MA 02110 0 1 0 0 VP & Chief Accounting Officer Common Stock, par value $.01 per share 1576 D Restricted Stock Units Common Stock 559 D Restricted Stock Units Common Stock 1696 D Restricted Stock Units Common Stock 2151 D The restricted stock units ("RSUs"), representing a contingent right to receive a total of 1,673 shares of Iron Mountain Incorporated common stock ("Common Stock"), were granted to the Reporting Person on February 19, 2015. As of October 17, 2017, 1,114 of the granted RSUs have vested, and the balance of the RSUs vest on February 19, 2018. Each RSU represents a contingent right to receive one share of Common Stock. The RSUs, representing a contingent right to receive a total of 2,542 shares of Common Stock, were granted to the Reporting Person on March 9, 2016. As of October 17, 2017, 846 of the granted RSUs have vested, and the balance of the RSUs vest in two substantially equal annual installments beginning on the second anniversary of the grant date. The RSUs, representing a contingent right to receive a total of 2,151 shares of Common Stock, were granted to the Reporting Person on February 16, 2017 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 October 23, 2017 from Daniel Borges 2017-10-27