UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of
the Securities Exchange Act of 1934 (Amendment No.          )

IRON MOUNTAIN INCORPORATED
NOTICE OF 20142015 ANNUAL MEETING OF STOCKHOLDERS
TO BE HELD ON MAY 29, 201428, 2015

To the Stockholders of
IRON MOUNTAIN INCORPORATED:

        Iron Mountain Incorporated will hold its 20142015 Annual Meeting of Stockholders at the offices of Sullivan & Worcester LLP, One Post Office Square, 21st Floor, Boston, Massachusetts 02109, on May 29, 2014,28, 2015, at 9:00 a.m. local time for the following purposes:

1.

To elect eleventen (10) directors to the Board of Directors of Iron Mountain Incorporated for a one-year term as directors or until their successors are elected and qualified;



2.

To hold a non-binding, advisory vote on the compensation of Iron Mountain Incorporated's named executive officers as described in the accompanying Proxy Statement;



3.

To ratify the selection by the Audit Committee of Deloitte & Touche LLP as Iron Mountain Incorporated's independent registered public accounting firm for the year ending December 31, 2014;2015; and



4.

To transact such other business as may properly come before the Annual Meeting.

        Attached to this notice is a Proxy Statement relating to the proposals to be considered at the Annual Meeting. The Board of Directors has fixed the close of business on April 3, 20142, 2015 as the record date for the determination of stockholders entitled to receive notice of and to vote at the Annual Meeting or at any adjournment or postponement thereof. This Proxy Statement is dated April 14, 2014.13, 2015.

        Securities and Exchange Commission rules allow us to furnish proxy materials to our stockholders on the internet. You can now access proxy materials and vote at www.proxyvote.com. You may also vote via internet or telephone by following the instructions on that website. In order to vote on the internet or by telephone you must have a stockholder identification number, which is being mailed to you on a Notice Regarding the Availability of Proxy Materials.

        YOUR VOTE IS IMPORTANT REGARDLESS OF THE NUMBER OF SHARES THAT YOU OWN.    We urge you to read the Proxy Statement carefully and, whether or not you plan to attend the Annual Meeting, to cast your vote without delay as instructed in the Notice Regarding the Availability of Proxy Materials that you receivedreceive in the mail. You may also request a paper proxy card at any time on or before May 15, 201414, 2015 to submit your vote by mail. Proxies may be revoked, or the votes reflected in the proxy changed, by (1) delivering written notice or another duly executed proxy bearing a later date to the Secretary of Iron Mountain Incorporated, (2) completing another proxy in the same manner indicated on the website referred to in the Notice Regarding the Availability of Proxy Materials or (3) attending the Annual Meeting and voting in person. If you hold shares in the name of a brokerage firm, bank, nominee or other institution, you must provide a legal proxy from that institution in order to vote your shares at the Annual Meeting, except as otherwise discussed in the Proxy Statement.

        All stockholders are cordially invited to attend the Annual Meeting.

        IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE ANNUAL MEETING OF STOCKHOLDERS TO BE HELD ON MAY 29, 2014:28, 2015: This Notice of Annual Meeting and Proxy Statement, Iron Mountain Incorporated's Annual Report to Stockholders for the year ended December 31, 20132014 and directions to the Annual Meeting are available at: www.materials.proxyvote.com/462846.46284V.

IRON MOUNTAIN INCORPORATED
PROXY STATEMENT
FOR THE 20142015 ANNUAL MEETING OF STOCKHOLDERS

To be held on May 29, 201428, 2015

GENERAL INFORMATION

        This Proxy Statement is furnished in connection with the solicitation of proxies by the Board of Directors, or the Board, of Iron Mountain Incorporated, or Iron Mountain, the Company, we, us or our, for use at the Annual Meeting of Stockholders to be held on May 29, 2014,28, 2015, or the Annual Meeting, or at any adjournment or postponement thereof. All stockholders of record on April 3, 20142, 2015 are invited to attend the Annual Meeting. The Company's Annual Report to Stockholders for the year ended December 31, 20132014 and the Notice Regarding the Availability of Proxy Materials relating to the Annual Meeting, or the Notice of Internet Availability, areis first being mailed to stockholders of the Company on or about April 14, 2014.13, 2015.

        Iron Mountain will bear all costs of solicitation of proxies. Brokers, banks, custodians and other fiduciaries will be requested to forward proxy solicitation materials to the beneficial owners of shares held of record by such persons, and the Company will reimburse them for their reasonable out-of-pocket expenses incurred in connection with the distribution of such proxy solicitation materials. Solicitation of proxies by mail may be supplemented by telephone, telecopier or personal solicitation by directors, officers or other regular employees of the Company (who will not receive any additional compensation for any solicitation of proxies).

        The Board unanimously recommends that you vote:

•

FOR the election of each of the Board's nominees for director;



•

FOR the approval of a non-binding, advisory resolution approving the compensation of ourthe Named Executive Officers (defined below) as described in this Proxy Statement; and



•

FOR the ratification of the selection by the Audit Committee of Deloitte & Touche LLP as the Company's independent registered public accounting firm for the year ending December 31, 2014.2015.

Stockholders Entitled to Vote

        Iron Mountain's common stock, $0.01 par value per share, or the Common Stock, is the only class of voting securities outstanding and entitled to vote at the Annual Meeting. As of the close of business on April 3, 2014,2, 2015, the record date for the determination of stockholders entitled to notice of and to vote at the Annual Meeting, or the Record Date, 191,916,171210,520,051 shares of Common Stock were outstanding and entitled to vote. Each share is entitled to one vote on each matter.

How to Vote

        Your vote is very important to the Board no matter how many shares of Common Stock you own. Whether or not you plan to attend the Annual Meeting, we urge you to vote your shares today.

        If you wish to receive a paper or email copy of the proxy card to complete and mail to the Company in time for the Annual Meeting, you may request one at any time on or before May 15, 2014.14, 2015. You may vote your shares over the internet or by telephone in the manner provided on the website indicated in the Notice of Internet Availability you receivedreceive in the mail, or the Website, by completing and returning a proxy card, or by attending the Annual Meeting and voting in person. Votes provided over the internet or by telephone must be received by 11:59 p.m. Eastern Daylight Time on May 28, 2014.27, 2015.

If You Are a Registered Holder of Common Stock

        If you are a registered holder of Common Stock, you may vote your shares either by voting by proxy in advance of the Annual Meeting or by voting in person at the Annual Meeting. By submitting a proxy (on a proxy card or in the manner provided on the Website), you are legally authorizing another person to vote your shares on your behalf. We urge you to vote (1) FOR the Board's nominees for director, (2) FOR the approval of a non-binding, advisory resolution approving the compensation of our Named Executive Officers as described in this Proxy Statement and (3) FOR the ratification of the selection by the Audit Committee of Deloitte & Touche LLP as the Company's independent registered public accounting firm for the year ending December 31, 2014.2015. If you submit your executed proxy card or submit a proxy in the manner provided on the Website, your shares will be voted as specified by you on the proxy and, unless otherwise directed, will be voted in accordance with the Board's recommendations set forth in this Proxy Statement.Statement, unless otherwise directed, in which case your shares will be voted as specified by you on the proxy. In addition, if any other matters are brought before the Annual Meeting (other than the proposals contained in this Proxy Statement), then the individuals listed on the proxy will have the authority to vote your shares on those other matters in accordance with their discretion and judgment.

        In case a quorum is not present at the Annual Meeting, the holders of a majority of the voting power of the shares present at the Annual Meeting in person or represented by proxy may adjourn the Annual Meeting (without notice other than announcement of adjournment at the Annual Meeting) to another time, or to another time and place.

        Whether or not you plan to attend the Annual Meeting, we urge you to promptly vote over the internet or by telephone in the manner provided on the Website or by completing and returning a proxy card. If you later decide to attend the Annual Meeting and vote in person, the vote you cast in person at the Annual Meeting will automatically revoke any previously submitted proxy.

If You Hold Your Shares of Common Stock "In Street Name"

        If your shares are held in the name of a brokerage firm, bank, nominee or other institution (referred to as "in street name"), you will receive instructions from the holder of record, or street name holder, that you must follow in order for you to specify how your shares will be voted. If you do not specify how you would like your shares to be voted, your shares held in street name may still be voted. Certain street name holders have the authority to vote shares for which their customers do not provide voting instructions on certain routine, uncontested items.

        IMPORTANT: If your shares are held in the name of a brokerage firm, bank, nominee or other institution, you should provide instructions to your broker, bank, nominee or other institution on how to vote your shares. Please contact the person responsible for your account and give instructions for a proxy to be completed for your shares.

Quorum

        The presence at the Annual Meeting, in person or by proxy, of stockholders entitled to cast at least a majority of the votes that all stockholders are entitled to cast at the Annual Meeting will constitute a quorum. Shares represented by valid proxies will be treated as present at the Annual Meeting for purposes of determining a quorum, without regard to whether the proxy is noted as casting a vote or abstaining. Shares represented by broker non-votes will be treated as present for purposes of determining a quorum. Shares voted by a broker on any issue other than a procedural motion will be considered present for all quorum purposes, even if the shares are not voted on every matter.

Votes Required

        As more fully described in this Proxy Statement:

•

Each nominee for director must receive a majority of the votes cast on his or her nomination to be elected;



•

Approval of a non-binding, advisory resolution approving the compensation of our Named Executive Officers as described in this Proxy Statement requires the affirmative vote of a majority of the votes cast on the proposal; and



•

Approval of the proposal to ratify the selection of the Company's independent registered public accounting firm requires the affirmative vote of a majority of the votes cast on the proposal.

Abstentions and Broker Non-Votes

        A "broker non-vote" occurs on an item when a broker identified as the record holder of shares is not permitted by the rules of the New York Stock Exchange, or the NYSE, to vote on that item without instruction from the beneficial owner of the shares and no instruction has been received.received with respect to that item. Under the NYSE rules, brokers may vote on "routine" matters even without instructions from the street name holder. The election of directors and the advisory vote on executive compensation are not "routine" matters for purposes of broker voting. If you do not instruct your broker how to vote with respect to these items, your broker may not vote with respect to these proposals and your shares will be counted as "broker non-votes." The ratification of the selection of our independent registered public accounting firm for the fiscal year ending December 31, 20142015 is a routine matter; therefore, there will be no broker non-votes in connection with that matter.

        A properly completed proxy, if received in time for voting and not revoked, will be voted at the Annual Meeting in accordance with the instructions contained therein, and, unless otherwise directed, the shares represented by the proxy card will be voted:

•

"For" the election of the Board's nominees for director listed in this Proxy Statement;



•

"For" the approval of a non-binding, advisory resolution approving the compensation of our Named Executive Officers as described in this Proxy Statement; and



•

"For" the ratification of the selection by the Audit Committee of Deloitte & Touche LLP as the Company's independent registered public accounting firm for the year ending December 31, 2014.2015.

        Abstentions and broker non-votes will not be counted as votes cast and, therefore, will not affect the proposals that are being submitted to the stockholders at the Annual Meeting. Although the advisory vote on the proposed resolution to approve the compensation of the Company's Named Executive Officers is non-binding, the Compensation Committee of the Board will consider the outcome of the vote when making future compensation decisions for the Company's Named Executive Officers.

Attendance at the Annual Meeting

        Attendance at the Annual Meeting or any adjournment or postponement thereof will be limited to stockholders of record of the Company as of the close of business on the Record Date and guests of the Company. If you are a stockholder of record as of the close of business on the Record Date, your name will be verified against the list of stockholders of record prior to your admittance to the Annual Meeting or any adjournment or postponement thereof. Please be prepared to present photo identification for admission. If you hold your shares in street name, you will need to provide proof of beneficial ownership, such as a brokerage account statement, a copy of a voting instruction form

provided by your custodian with respect to the

Annual Meeting or other similar evidence of ownership, as well as photo identification, in order to be admitted to the Annual Meeting. Please note that if you hold your shares in street name and intend to vote in person at the Annual Meeting, you must also provide a "legal proxy" obtained from your custodian.

Revocability of Proxies

        Any stockholder giving a proxy in the manner set forth in the Notice of Internet Availability has the power to revoke such proxy at any time before it is exercised. If you are a registered holder of Common Stock, you may revoke a previously submitted proxy by voting over the internet or by telephone at a later time in the manner provided on the Website. Any such notice or vote must be received by 11:59 p.m. Eastern Daylight Time on May 28, 2014.27, 2015. You may also revoke your proxy by attending the Annual Meeting and voting in person.

        Please note, however, that only your last-dated proxy will count, and any proxy may be revoked at any time prior to its exercise at the Annual Meeting, as described in this Proxy Statement.

        If your shares are held in the name of a brokerage firm, bank, nominee or other institution, and you have instructed your brokerage firm, bank, nominee or other institution to vote your shares, you must follow the instructions received from your brokerage firm, bank, nominee or other institution to change your voting instruction. Please contact your custodian for detailed instructions on how to revoke your voting instruction and the applicable deadlines.

        Our principal executive offices are located at One Federal Street, Boston, Massachusetts 02110.

        The Company's website address, www.ironmountain.com, is included several times in this Proxy Statement as a textual reference only, and the information in the Company's website is not incorporated by reference into this Proxy Statement.

Notice Regarding the Availability of Proxy Materials

        In accordance with rules and regulations of the Securities and Exchange Commission, or the SEC, instead of mailing a printed copy of our proxy materials to each stockholder of record, the Company may furnish proxy materials via the internet. Accordingly, all of the Company's stockholders will receive a Notice of Internet Availability, which will be mailed on or about April 14, 2014.13, 2015.

        On the date of mailing the Notice of Internet Availability, stockholders will be able to access all of the proxy materials at www.materials.proxyvote.com/462846.46284V. The proxy materials will be available free of charge, and the Notice of Internet Availability will provide instructions as to how you may access and review all of the important information contained in the proxy materials (including the Company's Annual Report to stockholders) over the internet or through other methods specified on the Website. The Website contains instructions as to how to vote by internet or over the telephone. The Notice of Internet Availability also instructs you as to how you may request a paper or email copy of the proxy card. If you receivedreceive a Notice of Internet Availability and would like to receive printed copies of the proxy materials, you should follow the instructions for requesting such materials included in the Notice of Internet Availability.

ITEM 1

ELECTION OF DIRECTORS

        The Board currently consists of twelveeleven directors. In March 2014,February 2015, the size of the Board was set at 11ten (10) directors, to take effect immediately at the conclusion of the Annual Meeting. Each current director, other than Mr. Walter C. Rakowich,Ms. Jennifer Allerton, who joined the board on August 16, 2013,September 15, 2014, served for a one-year term, and the term of each director, including Mr. Rakowich,Ms. Allerton, will expire at the Annual Meeting. Mr. Arthur D. Little and Ms. Laurie A. Tucker areMichael Lamach is not standing for re-election at the Annual Meeting.

        At the Annual Meeting, all nominees are to be elected for one-year terms to serve until the Company's 20152016 Annual Meeting of Stockholders, or until their successors are elected and qualified. The Board has selected as nominees the following eleventen (10) individuals, all of whom with the exception of Ms. Pamela M. Arway, are current directors of the Company: Jennifer Allerton, Ted R. Antenucci, Pamela M. Arway, Clarke H. Bailey, Kent P. Dauten, Paul F. Deninger, Per-Kristian Halvorsen, Michael W. Lamach, William L. Meaney, Walter C. Rakowich Vincent J. Ryan and Alfred J. Verrecchia. Each nominee has agreed to serve if elected, and management has no reason to believe that any of the nominees will be unavailable to serve.

Required Vote

        Each nominee for director must receive a majority of the votes on his or her nomination to be elected. This means a nominee will be elected to the Board only if the votes cast "For" such nominee's election exceed the votes cast "Against" such nominee's election, with abstentions and broker non-votes not counting as votes "For" or "Against." Under the Company's Bylaws, if the number of votes cast "For" a director nominee does not exceed the number of votes "Against" the director nominee, and if the nominee is an incumbent director, then he or she must promptly tender his or her resignation from the Board. Each incumbent director has already tendered an irrevocable resignation that will be effective upon (1) the failure to receive the required number of votes for re-election at the Annual Meeting or any meeting of stockholders at which he or she faces re-election and (2) the acceptance of such resignation by the Board. The Board will decide within ninety90 days of the certification of the stockholder vote, through a process managed by the Nominating and Governance Committee of the Board and excluding the nominee in question, whether to accept the resignation. The Board's explanation of its decision will be promptly disclosed in a filing with the SEC.

        As previously mentioned, brokers are not permitted to vote your shares for the election of directors absent instruction from you. Therefore, we urge you to give voting instructions to your broker on the proxy so that your votes may be counted on this important matter.

        The Board recommends that you vote FOR the election of each of the Board's eleventen (10) nominees to serve as directors of Iron Mountain until the 20152016 Annual Meeting of Stockholders, or until their successors are elected and qualified.

Information Concerning the Directors and Director Nominees

        Set forth below is the name and age of each of our director nominees and his or her principal occupation as of April 3, 2014,15, 2015, as well as his or her business experience during the past five years and the names of certain other companies of which he or she currently serves as a director or has served as a director during the past five years. In addition to the information presented below regarding each nominee's specific experience, qualifications, attributes and skills that led our Board to the conclusion that he or she should serve as a director, we also believe that all of our director nominees have a reputation for integrity and sound judgment and excellent analytical skills. Each of our director nominees has demonstrated business acumen and complements the attributes and skills of the other

director nominees. Each of the nominees has consented to be named in this Proxy Statement and to serve on the Board, if elected.

Directors Not Standing for Re-Election

        At a meeting to be held immediately followingThe Board annually elects the Annual Meeting, the Board currently intends to elect officers of the Company. Each officer holds office at the discretion of the Board until the first meeting of the Board following the next annual meeting of stockholders or until such officer sooner dies, resigns or is removed. There are no family relationships between or among any of the Company's officers or directors.

        Set forth below is the name and age of each of our executive officers who is not nominated to be a director of the Company, his or her principal occupation and business experience during the past five years and the names of certain other companies of which he or she served as a director, as of April 3, 2014.15, 2015.

Board of Directors and Committees

        Independence.    Our Board is composed of a majority of directors who qualify as independent directors pursuant to the corporate governance standards for companies listed on the NYSE. The Board evaluates independence pursuant to NYSE standards each year by affirmatively determining whether each director has a direct or indirect material relationship with the Company (including its subsidiaries) and members of the Company's management that may interfere with such director's ability to exercise his or her independence from the Company. When assessing the materiality of a director's

relationship with the Company, the Board considers all relevant facts and circumstances, not merely from the director's standpoint but from that of the persons or organizations with which the director has an affiliation. Material relationships can include commercial, industrial, banking, consulting, legal, accounting, charitable and familial relationships. None of our independent directors (other than Mr. Deninger and Mr. Ryan)Deninger) has any relationship with the Company or its management other than his or her service as a director and on committees of the Board, and the Board has concluded that none of thesethe Company's directors possess the objective relationships set forth in the NYSE listing standards that prevent independence.

        In assessing the independence of Mr. Ryan, the Board considered Mr. Ryan's position with Schooner, which subleased space from the Company under a sublease agreement until such agreement was terminated in connection with the relocation of the Company's headquarters, as further described under the "Certain Relationships and Related Transactions" section of this Proxy Statement. The Board determined that, because Schooner paid market rent, subject to certain adjustments for utilities, to the Company prior to the termination of the sublease agreement, this relationship would not interfere with Mr. Ryan's ability to exercise independence from the Company.

        In assessing the independence of Mr. Deninger, the Board considered Mr. Deninger's position as a senior managing director at Evercore Partners Inc., or Evercore. In 2013 the Company entered into an agreement with Evercore providedpursuant to which Evercore agreed to provide financial advisory services to the Company, in 2013, as further described under the "Certain Relationships and Related Transactions" section of this Proxy Statement. In 2014 the Company incurred the final $250,000 of fees associated with the agreement with Evercore. The Board determined that, because Mr. Deninger agreed to waive any direct fees he may receive in connection with the Evercore engagement and did not work on the engagement on behalf of Evercore, this relationship would not interfere with Mr. Deninger's ability to exercise independence from the Company.

        The Board has determined that all of our non-management directors qualify as independent under NYSE rules. One of our directors, Mr. Meaney, is a management employee involved in our day-to-day activities and is not considered to be an independent director.

        Attendance.    During the fiscal year ended December 31, 2013,2014, the Board held seven meetings and took three actions by written consent.11 meetings. Each incumbent director, except for Ms. Allerton, attended at least 75% of the aggregate number of meetings of the Board and all committees thereof on which such director served that were held during the period for which such director served. Ms. Allerton joined the Board on September 15, 2014 and attended four Board and committee meetings, but was unable to attend two committee meetings on a particular date due to a conflicting commitment that existed prior to her appointment to the Board. All of our directors standing for re-election at the time attended our 20132014 Annual Meeting of Stockholders. All directors standing for re-election are expected to attend the Annual Meeting. Our policy with respect to directors' attendance at our annual meetings of stockholders can be found in our

Corporate Governance Guidelines, the full text of which appears under the heading "Company/For Investors/Corporate Governance" on our website at www.ironmountain.com.

Board Leadership Structure.Structure

        The Board does not have a formal policy as to whether the roles of Chairman and CEO should be combined or separated. The Board believes that Iron Mountain stockholders are best served by the Board having flexibility to consider the relevant facts and circumstances whenand determine, at the Chairman is elected at any given point in time based on whatof the Board believes will provideChairman's election, the best leadership structure for the Company at that time, rather than by adhering to a formal standing policy on the subject.

        The Board has acknowledged that the decision to separate the roles of Chairman and CEO depends in large part on the current and expected needs of the Company. As a result of the Board's ongoing review of its leadership structure, the Board has determined that the position of Chairman should be held by a non-employee of the Company. In considering the decision as to whether to separate the roles of Chairman and CEO, the Board acknowledged that the decision is company specific and should depend in large part on the current needs of the Company. The Board believes that the current leadership structure, which separates the roles of CEO and Independent Chairman, fosters effective governance and oversight of the Company. The Independent Chairman controls the Board meeting agendas, which ensures that topics deemed important by the independent directors are included in Board discussions and best enables the Board to express its views

on our management, strategy and execution. We believe this governance structure promotes balance between the authority of those who oversee our business and those who manage it on a day-to-day basis. The CEO is responsible for setting the Company's strategy and leading the organization's day-to-day performance. The Independent Chairman is responsible for advising the CEO and presiding over meetings of the Board, presiding over all executive sessions of non-management directors, consulting with the CEO on Board meeting agendas and acting as a liaison between management and non-management directors. The CEO is responsible for setting the Company's strategy and leading the organization's day-to-day performance. We believe this governance structure promotes balance between the authority of those who oversee our business and those who manage it on a day-to-day basis.

        The Board generally convenes in non-management executive session after each Board meeting.

        Committees.Committees

        The Board has the following standing committees: Audit Committee, Compensation Committee, Nominating and Governance Committee, Finance Committee and FinanceRisk and Safety Committee. The Board has adopted a charter for each of its standing committees, all of which areand each such charter is available on our website at www.ironmountain.com under the heading "Company/For Investors/Corporate Governance." Each standing committee has conducted annual self-evaluations and will continue to conduct annual self-evaluations under the oversight of the Nominating and Governance Committee, which will also oversee an annual review of the Board, including evaluations of individual Board members. These self-evaluations are intended to facilitate an examination and discussion by the entire Board and each director and each of these committees of their effectiveness as a group in fulfilling charter requirements and other responsibilities, as well as areas for improvement. During the fiscal year ended December 31, 2013,2014, the Audit Committee held 12seven meetings, and took one action by written consent, the Compensation Committee held eightnine meetings, and took one action by written consent, the Nominating and Governance Committee held fivesix meetings, and took one action by written consent and the Finance Committee held sevenfive meetings and took no action by written consent.the Risk and Safety Committee, which was formed in May 2014, held two meetings.

        The Nominating and Governance Committee annually reviews the composition of the Board committees and considers whether to recommend committee membership changes to the Board. As part of this process in 2014, the Board rotated several committee members and chairs. In 2014 at least one new member joined each committee, and each committee also maintained several of its existing members for continuity.

        Membership on each committee as of April 1, 20142015 is set forth in the chart below.

Committee Membership

        Audit Committee.    Each member of the Audit Committee is independent as defined by the rules of the SEC, the NYSE listing standards and the Audit Committee Charter. In addition, the Board has determined that each member of the Audit Committee is an audit committee financial expert as defined by the rules of the SEC and is financially literate as defined by the NYSE listing standards. The Audit Committee: (1) assists the Board in oversight of the integrity of the Company's financial

statements; (2) assists the Board in oversight of the Company's compliance with legal and regulatory requirements; (3) assists the Board in oversight of the independent registered public accounting firm's retention, qualifications and independence; (4) assists the Board in oversight of the performance of the Company's internal audit function and independent auditors; (5) prepares an Audit Committee report as required by the SEC to be included in the annual Proxy Statement; (6) performs such other duties as the Board may assign to the Audit Committee from time to time, such as approving transactions subject to our Related Person Transaction Policies and Procedures described on pages 74 and 75page 67 of this Proxy Statement; and (7) takes other actions to meet its responsibilities as set forth in its written charter. The Audit Committee is also responsible for establishing procedures for the receipt, retention and treatment of complaints regarding accounting, internal accounting controls and auditing matters, including procedures for the confidential and anonymous submission by employees of the Company of any concerns regarding accounting or auditing matters they think may be questionable. Information about these procedures can be found on our website, www.ironmountain.com, under the heading "Company/For Investors/Corporate Governance."

        Compensation Committee.    Each member of the Compensation Committee qualifies as independent under the NYSE listing standards. The Compensation Committee: (1) reviews, approves and recommends to the independent members of the Board the base salary, equity-based incentives and the payment of short-termshort- term incentive compensation for the CEO; (2) approves all long-term equity incentives to our employees, including Messrs. Cloutier, Day, Duale, EbbighausenMeaney and Meaney, Ms. Drapeau, Mr. Brian McKeon, our former Chief Financial Officer, and Mr. C. Richard Reese, our former CEO,Tomovcsik, or the Named Executive Officers, under the Iron Mountain Incorporated 2002 Stock Incentive Plan, or the 2002 Plan, and the 2014 Stock and Cash Incentive Plan, or the 2014 Plan; (3) reviews and approves the annual cash compensation for Named Executive Officers (other than the CEO) based on recommendations from the CEO and reports to the Board on such decisions; (4) reviews the Company's cash and stock-based incentive compensation plans to assess their effectiveness in meeting the Company's goals and objections and exercises all of the authority of the Board with respect to the

administration of such plans; (5) annually reviews and discusses with management a draft of the Company's Compensation Discussion and Analysis to be included in the Company's Annual Report on Form 10-K and annual proxy statement; (6) annually prepares and publishes an annual report of the Compensation Committee for inclusion in the Company's Annual Report on Form 10-K and annual proxy statement; (7) reviews and discusses at least on an annual basis the risks arising from the Company's compensation policies for its employees; and (8) takes other actions to meet its responsibilities as set forth in its written charter.

        The Board has delegated final authority for compensation decisions for the Named Executive Officers, other than our CEO, to the Compensation Committee. The Compensation Committee has the authority to delegate any of its responsibilities to a sub-committee composed of members of the Compensation Committee, but it has not done so to date.

        For a discussion concerning the process and procedures for determining executive compensation and the role of executive officers and compensation consultants in determining or recommending the amount or form of compensation, see the "Compensation Discussion and Analysis" section in this Proxy Statement.

        Nominating and Governance Committee.    Each member of the Nominating and Governance Committee qualifies as independent under the NYSE listing standards. The Nominating and Governance Committee: (1) recommends the composition of the Board; (2) identifies and recommends candidates for nomination to the Board; (3) recommends to the Board structures and statements of the duties and responsibilities of each committee of the Board; (4) develops and recommends to the Board and implements corporate governance guidelines applicable to the Company; (5) assists the Board in annually reviewing management succession; (6) develops and monitors an annual process to assess the effectiveness of the Board and implements and oversees an annual review of the performance of the Board (including evaluations of individual Board members) and each of the Board's standing

committees; (7) develops and proposes, for approval by the Board, compensation policies for the Company's non-employee directors; (8) annually reviews contributions to candidates made by the Iron Mountain Incorporated Political Action Committee, or IMPAC, and determines the composition of the IMPAC board; and (9) takes other actions to meet its responsibilities as set forth in its written charter.

        Finance Committee.    Although the NYSE listing standards do not require members of the Finance Committee to be independent, all members of the Finance Committee qualify as independent under the NYSE listing standards and the Board's assessment of any material relationships with the Company. The Finance Committee: (1) reviews the Company's capital structure and financial strategies; (2) reviews the Company's material capital allocation decisions, strategic investments and dispositions and other opportunities for maximizing stockholder value; (3) considers and reviews the Company's dividend and share repurchase policies and programs and other strategies to return capital to stockholders; (4) reviews the Company's derivatives and hedging policies and strategies; (5) reviews the Company's investment policies and practices; (6) reviews the Company's credit ratings and strategy, (7) periodically reviews the Company's investor relations strategy, (8) furnishes periodic reports to the Board concerning the Finance Committee's work; and (7)(9) performs such other duties as the Board may assign to the committee from time to time.

        Risk and Safety Committee.    The Risk and Safety Committee (1) reviews and monitors material safety, security, business continuity, information security and risk management strategies and systems; (2) reviews and monitors material safety, security, business continuity, information security and risk management policies and processes implemented, established and reported on by the Company's management and (3) takes other actions to meet its responsibilities as set forth in its written charter.

Board and Committee Evaluations

        The Nominating and Governance Committee oversees the Board and committee evaluation process. Generally, including in 2014, the Board and each committee conduct self-evaluations by means of written questionnaires completed by each director and committee member. The anonymous responses are summarized and provided to the Board and each committee at their next meetings in order to facilitate an examination and discussion by the Board and each committee of the effectiveness of the Board, committees, individual directors, Board and committee structure and dynamics, and areas for possible improvement. In 2013, the Nominating and Governance Committee engaged an independent third party firm to conduct a comprehensive independent evaluation of the Board, the committees and individual directors. The evaluation process consisted of confidential written questionnaires and one-on-one interviews of our directors and management. The resulting information was compiled and summarized by the independent third party and then reviewed and discussed at a subsequent Board meeting. The Nominating and Governance Committee establishes the board and committee evaluation process each year and may determine to use an independent third party evaluation process from time to time in the future.

Risk Oversight

        The Board is responsible for oversight of the Company's management of enterprise risks. Iron Mountain senior management is responsible for the Company's risk management process and the day-to-day supervision and mitigation of enterprise risks. The Board receives regular reports on areas of material Company risk, including strategic, operational, financial, legal and regulatory risks. The full Board, or the committee of the Board assigned responsibility for ana specific area of risk, receives reports from the Company executive accountable for understanding and mitigating the identified risk. Historically, of the Board's committees, the Audit Committee has led the oversight of a majority of the risk mitigation initiatives associated with the Company's enterprise risk assessment and management efforts. When a committee of the Board receives a risk report, the chairman of such committee provides a summary of the discussion to the Board during the next regularly scheduled Board meeting. This practice allows the Board and each of its committees to remain coordinated in their oversight of enterprise risk.

        Historically, the Audit Committee has led the oversight of a majority of the risk mitigation initiatives associated with the Company's enterprise risk assessment and management efforts. In furtherance of its commitment to risk oversight, the Board formed a Risk and Safety Committee in May 2014 to, among other things, provide additional support to the Board in ensuring that the Company's enterprise risk management program is established appropriately and operating effectively.

Political Expenditures

        Our Global Political Contribution Policy, together with our Code of Ethics and Business Conduct, guide our approach to ethical business behavior and corporate political contributions. Our Global Political Contribution Policy provides that Iron Mountain does not make political contributions in any form or amount from corporate funds or resources, even when permitted by applicable law. This means corporate funds are not used in support of or opposition to political candidates, political parties, political committees and other political entities organized and operating for political candidates. In addition, corporate funds are not used for "electioneering" communications.

        The Company administers IMPAC, which is a non-partisan political action committee supporting congressional candidates at the federal level only. IMPAC allows eligible employees to pool their resources to support candidates who understand the issues important to the Company's business and its employees. Participation in IMPAC is strictly voluntary. Except for administrative expenses, IMPAC is funded solely by the Company's employees and directors and is not supported by funds from the Company. IMPAC complies with federal election laws and all other applicable laws, and reports regularly to the Federal Elections Commission. In addition, IMPAC is governed by a set of bylaws and supervised by a board of directors composed of senior managers from different areas of the Company.

        The Company is a member of a number of trade associations that participate in public relations activities such as education and conferences, but not for the purpose of making political contributions. Our Code of Ethics and Business Conduct and our Global Political Contribution Policy are available on our website under the heading "Company/For Investors/Corporate Governance."

Stockholder Communications to Board of Directors

        The Board believes it is important to engage effectively with stockholders. To facilitate this engagement, the Board believes it is important for stockholders and others to have a process to send communications to the Board. Accordingly, any stockholder, security holder or other interested party who desires to communicate with the Board, any individual director, including the Independent Chairman, or the independent or non-management directors as a group, may do so by regular mail or email directed to the Secretary of the Company. The Secretary's mailing address isCommunications to the Board should be mailed to Corporate Secretary, c/o Iron Mountain Incorporated, One Federal Street, Boston, Massachusetts 02110; the Secretary's email address is corporatesecretary@ironmountain.com. Upon receiving such mail or email, the Secretary will assess the appropriate director or directors to receive the message and will forward the mail or email to such director or directors without editing or altering it.

Selection of Board of Directors Nominees

        The Board is responsible for developing and approving criteria, in addition to those set forth in our Corporate Governance Guidelines, for candidates for Board membership. The Nominating and Governance Committee is responsible for seeking candidates to become Board members, consistent with the criteria set forth in the Corporate Governance Guidelines and approved by the Board, and for recommending candidates to the entire Board for selection by the Board for nomination to fill vacancies on the Board or expiring terms of directors at each annual meeting of stockholders. The Board as a whole is responsible for nominating individuals for election to the Board by the stockholders and for filling vacancies on the Board that may occur between annual meetings of the stockholders.

        Nominees for director will be selected on the basis of their integrity, experience, achievements, judgment, intelligence, personal character, ability to make independent analytical inquiries, willingness to devote adequate time to Board duties and likelihood that they will be able to serve on the Board for a sustained period. In connection with the selection of nominees for director, the Board's policy is to give due consideration to the Board's overall balance of diversity of perspectives, backgrounds and experiences. To implement and review the effectiveness of our diversity policy, the Nominating and Governance Committee reviews the appropriate skills and characteristics of members of the Board in the context of the then current composition of the Board. It is the practice of the Nominating and Governance Committee to then consider these factors when screening and evaluating candidates for nomination or re-election to the Board. The Board will not nominate for election as director any candidate who has not agreed to tender, promptly following the annual meeting at which he or she is elected as director, an irrevocable resignation that will be effective upon (1) the failure to receive the required number of votes for re-election at the next annual meeting of stockholders at which he or she faces re-election, and (2) acceptance of such resignation by the Board.

        The Nominating and Governance Committee will consider, as part of the process for identifying individuals who might be candidates, individuals who are properly recommended by stockholders for nomination by the Board at a meeting of stockholders at which directors are to be elected. To be proper, a recommendation for a nominee for director with respect to a meeting of stockholders must comply with applicable law, the Company's Bylaws and the Company's Corporate Governance Guidelines. The Nominating and Governance Committee will consider any suggestions offered by other directors or stockholders with respect to potential directors, and there will be no difference in the

manner in which potential nominees are evaluated. However, the Nominating and Governance Committee and the Board are not required to enlarge the size of the Board in order to nominate an

otherwise fully qualified candidate proposed by a stockholder. A stockholder wishing to nominate a director directly must comply with the procedures described below.in the Company's Bylaws and this Proxy Statement.

        TheIn 2014 the Nominating and Governance Committee retained the services of Egon Zehnder International, or Egon Zehnder, in connection with (1) itsthe Company's search for a new director to fill the vacancy on the Board due to Mr. Allan Loren's retirement from the Board effective as of the date of the 2013 Annual Meeting of Stockholders and (2) its search for an additional new directordirectors as part of its boardthe Board's succession planning process. Egon Zehnder providesprovided the Nominating and Governance Committee with lists of candidates that meet criteria established by the Board and assistsassisted the Nominating and Governance Committee in meeting and assessing the qualifications of candidates in order to assist the committee with its review of potential candidates. Mr. Walter C. Rakowich and Ms. Pamela M. Arway and Ms. Jennifer Allerton, who joined the Board as directors in 2014, were candidates identified by Egon Zehnder.

Nominations and Proposals of Stockholders

        A stockholder who, in accordance with Rule 14a-8, or Rule 14a-8, under the Securities Exchange Act of 1934, as amended, or the Exchange Act, wants to present a proposal for inclusion in the Company's 20152016 Proxy Statement and proxy card relating to the 20152016 Annual Meeting of Stockholders must submit the proposal by December 15, 2014.2015. In order for the proposal to be included in the Proxy Statement, the stockholder submitting the proposal must meet certain eligibility standards and comply with certain regulations established by the SEC.

        Stockholders who wish to present a business proposal or nominate persons for election as directors at the Company's 20152016 Annual Meeting of Stockholders must provide a notice of the business proposal or nomination in accordance with Section 2.4 of our Bylaws, in the case of business proposals, or Section 3.2 of our Bylaws, in the case of director nominations. In order to be properly brought before the 20152016 Annual Meeting of Stockholders, Sections 2.4 and 3.2 of our Bylaws require that a notice of the business proposal the stockholder wishes to present (other than a matter brought pursuant to Rule 14a-8), or the person or persons the stockholder wishes to nominate as a director, must be received at our principal executive office not less than ninety90 days, and not more than 120 days, prior to the first anniversary of the Company's prior year's annual meeting. Therefore, any notice intended to be given by a stockholder with respect to the Company's 20152016 Annual Meeting of Stockholders pursuant to our Bylaws must be received at our principal executive office no earlier than January 29, 20152016 and no later than February 28, 2015.27, 2016. However, if the date of our 20152016 Annual Meeting of Stockholders occurs more than thirty30 days before or thirty30 days after May 29, 2015,28, 2016, the anniversary of the 20142015 Annual Meeting of Stockholders, a stockholder notice will be timely if it is received at our principal executive office by the later of (1) the 120^th day prior to such annual meeting or (2) the close of business on the tenth day following the day on which public disclosure of the date of the meeting was made. To be in proper form, a stockholder's notice must include the specified information concerning the stockholder and the business proposal or nominee, as described in Sections 2.4, 3.2 and 3.3 of our Bylaws.

        All proposals must be mailed to the Company's principal executive office, at the address stated herein, and should be directed to the attention of the Secretary of the Company.

Code of Ethics

        Our Code of Ethics and Business Conduct applies to each of the Company's employees, including officers, and directors. Our Code of Ethics and Business Conduct is posted on our website, www.ironmountain.com, under the heading "Company/For Investors/Corporate Governance." A printed copy of our Code of Ethics and Business Conduct is also available free of charge to any stockholder who requests a copy. We intend to disclose any amendment to, or waiver from, a provision of our Code of Ethics and Business Conduct applicable to the Company's CEO, chief financial officer or principal accounting officer or controller by posting such information on our website. Any waivers applicable to any other executive officers will also be promptly disclosed to stockholders on our website.

ITEM 2

ADVISORY VOTE ON THE COMPENSATION OF OUR NAMED EXECUTIVE OFFICERS

        In accordance with the requirements of Section 14A of the Exchange Act (which were added by the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010), and related rules of the SEC, we are including this separate proposal subject to stockholder vote to approve, on a non-binding, advisory basis, the compensation of our Named Executive Officers listed in the "Summary Compensation Table" appearing elsewhere in this Proxy Statement, as disclosed in this Proxy Statement pursuant to Item 402 of Regulation S-K.

        Our executive compensation is designed to reward executive performance that contributes to our success while encouraging behavior that is in our and our stockholders' long-term best interests. We also seek to attract, motivate, reward and retain the senior management talent required to achieve our corporate objectives and increase stockholder value. At the core of our executive compensation program is our "pay for performance" philosophy that links competitive levels of compensation to achievements of our overall strategy and business goals, as well as predetermined objectives. We believe our compensation program is strongly aligned with the interests of our stockholders and sound corporate governance principles. We urge you to read the "Compensation Discussion and Analysis" section and compensation tables and narrative discussion in this Proxy Statement for additional details on our executive compensation, including our compensation philosophy and objectives and the compensation of our Named Executive Officers.

        The vote on this proposal is not intended to address any specific element of compensation; rather, the vote relates to the compensation of our Named Executive Officers, as described in this Proxy Statement in accordance with the compensation disclosure rules of the SEC. To the extent there is any significant vote against the compensation paid to the Named Executive Officers as disclosed in this Proxy Statement, the Compensation Committee will evaluate whether any actions are necessary to address the concerns of stockholders.

        Based on the above, we request that you indicate your support for our executive compensation philosophy and practices by voting to approve, on a non-binding, advisory basis, the following resolution:

        "RESOLVED, that the compensation paid to the Company's Named Executive Officers, as disclosed pursuant to Item 402 of Regulation S-K, including the Compensation Discussion and Analysis, compensation tables and narrative discussion in the Proxy Statement for the 20142015 Annual Meeting of Stockholders, is hereby APPROVED."

Required Vote

        The affirmative vote of a majority of the votes properly cast at the Annual Meeting is required to approve the compensation of our Named Executive Officers, as described in the "Compensation Discussion and Analysis" section, the compensation tables and the other narrative compensation disclosures contained in the Proxy Statement. For the purpose of determining whether a majority of the votes has been cast in favor of the approval of this resolution, only those cast "For" or "Against" are included, and any abstentions or broker non-votes will not count in making that determination. The opportunity to vote on this resolution is required pursuant to Section 14A of the Exchange Act. However, as an advisory vote, the vote on this resolution is not binding upon the Company and serves only as a recommendation to our Board. Nonetheless, the Compensation Committee, which is responsible for designing and administering our executive compensation program, and the Board value the opinions expressed by stockholders and will consider the outcome of the vote when making future compensation decisions for our Named Executive Officers.

        Our current policy is to provide stockholders with an opportunity to approve the compensation paid to our Named Executive Officers each year at our annual meeting of stockholders. We currently expect that the next such vote will occur at our 20152016 Annual Meeting of Stockholders.

        The Board recommends that you vote FOR the approval of the foregoing non-binding, advisory resolution approving the compensation of our Named Executive Officers.

ITEM 3

RATIFICATION OF THE SELECTION OF
INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

        Subject to ratification by the stockholders, the Audit Committee has selected the firm of Deloitte & Touche LLP as the Company's independent registered public accounting firm for the current year.

        Representatives of Deloitte & Touche LLP are expected to be present at the Annual Meeting. They will have the opportunity to make a statement if they desire to do so and will be available to respond to appropriate questions from stockholders who are present at the Annual Meeting.

        The fees we paid to Deloitte & Touche LLP in 20132014 are shown in the table appearing on page 7669 of this Proxy Statement.

        If the stockholders do not ratify the selection of Deloitte & Touche LLP as the Company's independent registered public accounting firm, the selection of accountants will be reconsidered by the Audit Committee.

Required Vote

        The affirmative vote of holders of a majority of the votes properly cast at the Annual Meeting is required to ratify the selection of Deloitte & Touche LLP to serve as the Company's independent registered public accounting firm for the current fiscal year. For purposes of determining the number of votes cast, only those cast "For" or "Against" are included, and any abstentions will not count in making that determination.

        The Board recommends that you vote FOR the ratification of the selection of Deloitte & Touche LLP.

SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

        The following table sets forth certain information known to the Company with respect to beneficial ownership of Common Stock by: (1) each director and nominee for director; (2) the Named Executive Officers; (3) all directors and executive officers of the Company as a group; and (4) each stockholder known by us to be the beneficial owner of more than 5% of the Common Stock. Such information is presented as of March 31, 2014,2015, except as otherwise noted.

Equity Compensation Plan Information

        The following provides certain equity compensation plan information with respect to all of our equity compensation plans in effect as of December 31, 2013:2014:

EXECUTIVE COMPENSATION

Compensation Discussion and Analysis

Executive Summary

        The primary objectives of our compensation programs are to reward the achievement of both Company and individual goals and to align the interests of our executives with the creation of stockholder value. In keeping with these objectives, our compensation programs are designed to align with our strategic objectives and reward teamwork and contribution to the successful achievement of our enterprise goals and financial objectives.

REIT Conversion

        As part of our plan to convert to a REIT for federal income tax purposes and elect REIT status effective January 1, 2014, we sought PLRs from the IRS relating to numerous technical tax issues, including classification of our steel racking structures as qualified real estate assets. We submitted the PLR requests in the third quarter of 2012 and, on June 25, 2014, we announced that we received the favorable PLRs from the IRS necessary for our conversion to a REIT. After receipt of the PLRs, the Board unanimously approved our conversion to a REIT for our taxable year beginning January 1, 2014. In connection with our REIT conversion:

•

attainingwe announced in September 2014 an increase of our target 25% Adjusted OIBDA marginquarterly dividend from $0.270 per share to $0.475 per share;



•

we paid a special distribution of $700 million, or the Special Distribution, in November 2014, which included the remaining amount of our international business unit;undistributed earnings and profits attributable to all taxable periods ending on or prior to December 31, 2013, which, in accordance with tax rules applicable to REIT conversions, we were required to pay to our stockholders on or before December 31, 2014; and



•

substantially completingwe paid a "catch-up" distribution of $0.255 per share in December 2014 because our cash dividends from January 2014 through July 2014 did not reflect the implementation of the necessaryfinal determination to elect REIT systems upgrades and changes to our legal entity structures to ensure we can successfully operate as a REIT as ofstatus effective January 1, 2014; however, we cannot provide assurance that we will, in fact, qualify as a REIT or remain so qualified.



•
We began implementation of our Strategic Plan by:



•

beginning to realign our organizational structure in North America to enhance performance accountability and focus on levers of revenue growth;



•

completing acquisitions to enter or expand our presence in emerging markets; and



•

making strategic investments in our data center business as part of our focus on identifying, incubating and scaling emerging business opportunities.



•
Our Compensation Committee continued its pay-for-performance focus.


•
Company performance was in line with external guidance but did not achieve the targets the Compensation Committee set to receive a full payout under our incentive plans. On average, our Named Executive Officers earned 89.5% of their short-term incentives and 70% of their PUs for 2013.


•
Our Compensation Committee reviewed and adjusted our incentive programs to ensure that they support our corporate strategy:


•
balanced Mr. Meaney's bonus opportunity between company financial and individual goals and objectives to more directly align his reward opportunity with goals that focused on developing our Strategic Plan and ensuring a smooth CEO transition internally and with investors;
2014.

        The total distributions to stockholders since 2010 now stand at approximately $3.5 billion through repurchases, stock distributions and cash dividends.

•

modified ourStrategic Plan

        During 2014 short-term incentivewe continued to align rewards with both (1) the achievement of our annual operating plan, with additional payout opportunity for profitable revenue growth in excess of targets, and (2) successful execution ofmake progress executing on the strategic investments necessary to achieve our Strategic Plan;



•

adopted a new long-term incentive strategy, which we expect to phaseplan developed by senior leadership in during 2014 and 2015, which focuses on long-term growth and performance, utilizing PUs based on relative Total Stockholder Return, or TSR, as well as stock options including premium-priced stock options for our CEO;



•

increased the required ownership levels under our Executive Stock Ownership Guidelines; and



•

engaged with shareholders during the fourth quarter of 2013, to better understand their views on compensation to assist in the evaluation of our program design.

Leadership Transition & Compensation

William L. Meaney

        Following the conclusion of an extensive CEO search process, on January 7, 2013, Mr. William L. Meaney succeeded Mr. Richard Reese as CEO. The terms of Mr. Meaney's offer letter, or the CEO Offer Letter, reflect the Company's pay for performance philosophy, the competition for Mr. Meaney's services as CEO and the relocation of Mr. Meaney's family from Hong Kong to Boston, Massachusetts, where the Company is headquartered.

        Mr. Meaney's 2013 compensation comprises an annual total direct compensation target of approximately $6.25 million, plus one-time awards of approximately $2.25 million. These one-time awards were delivered in the form of a cash signing bonus in the amount of $250,000 and an additional equity award opportunity in the amount of $2.0 million. In addition, Mr. Meaney was provided reasonable benefits related to his move from Hong Kong to Boston, Massachusetts, and reasonable employment and severance terms and conditions for a CEO. Specific detail related to Mr. Meaney's compensation is provided in the "CEO Compensation" section of this Proxy Statement.

        Key features of Mr. Meaney's compensation package (salary, short-term and long-term incentives) include:

•

an annual base salary representing a small percentage (16%) of his target total direct compensation, with the remaining 84% of his target total direct compensation earned based on the Company's financial performance, his achievement of individual goals and objectives and the Company's stock price appreciation;



•

participation in our short-term cash incentive program subject to the same financial performance metrics as our other executives with added emphasis on his individual goals and objectives reflecting key focus areas for 2013; and



•

long-term incentive awards, two-thirds of which are performance-based, including one-third PUs (the value of which is tied 50% to TSR relative to the S&P 500 (excluding financial services companies) over three years following the grant and tied 50% to the same financial performance metrics as our other executives for 2013); one-third stock options (the value of which is tied to the Company's stock price appreciation); and one-third RSUs that have a five-year vesting schedule, which is longer than our other executives, to encourage retention.

C. Richard Reese

        Following Mr. Meaney's appointment as CEO and into March 2013, Mr. Reese remained in his Executive Chairman role. Beginning in March 2013, Mr. Verrecchia assumed the role of Independent

Chairman, and Mr. Reese transitioned from Executive Chairman to special advisor to the Company and continues to serve in that role.

        The Compensation Committee approved a transition arrangement for Mr. Reese reflecting his expected activity for the period during which he serves as a special advisor. The transition arrangement provides for a salary for Mr. Reese of $150,000 per quarter from April 2013 through December 2013 and $25,000 per quarter from January 2014 through June 2014, when the transition arrangement is expected to expire. Mr. Reese was not eligible for a short-term incentive bonus in 2013 and was not awarded long-term incentive awards in 2013. In recognition of Mr. Reese's long-standing leadership and extraordinary service to the Company, the Compensation Committee approved a retirement gift for Mr. Reese paid for by the Company, valued at approximately $48,000, inclusive of taxes, which is detailed in the "Summary Compensation Table."

Chief Financial Officer

        On October 4, 2013, the Company and Mr. Brian McKeon mutually agreed that Mr. McKeon would step down as the Company's executive vice president and chief financial officer, effective October 31, 2013. Mr. McKeon remained an employee of the Company through December 31, 2013 to assist in the transition of responsibilities. Under the terms of his separation agreement, Mr. McKeon is entitled to be paid the benefits under the Company's plans, including without limitation the Iron Mountain Companies Severance Plan and Severance Program No. 1, or the Severance Program, which are described under the "Termination and Change of Control Arrangements" section of this Proxy Statement. In addition, Mr. McKeon's stock options were amended to provide an additional 120 days in which to exercise his vested stock options following the final day of his employment, which amendment was consistent with all employees that were affected by the realignment of our business in 2013. Further detail of Mr. McKeon's severance is provided in the "Separation Agreement with Brian P. McKeon" section of this Proxy Statement.

        Effective November 1, 2013, Mr. Roderick Day became interim Chief Financial Officer of the Company. In connection with this appointment, Mr. Day was provided a one-time award of RSUs equal to $500,000 to compensate him for his additional responsibilities. Effective March 14, 2014, the Board elected Mr. Day to serve as executive vice president and chief financial officer. In connection with this election, the Committee approved the following compensation arrangement for Mr. Day:

•

base salary of £300,000, or approximately $500,000 USD;



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target short-term performance-based incentive opportunity equal to 80% of salary;



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long-term incentive award equal to $800,000 in economic value under our 2014 long-term incentive program for executive vice presidents, which is described in the "2014 Program Changes" section of this Proxy Statement; and



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eligibility to receive severance benefits substantially similar to the benefits provided under the Severance Program.

Strategic Developments

        During 2013, we achieved several objectives from our 2011 multi-year strategic plan while developing and beginning implementation of our Strategic Plan.

2011 Multi-Year Strategic Plan

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During 2013, we achieved a 25% operating margin in our international segment.



•

During 2013, we substantially completed the necessary REIT systems upgrades and the changes to our legal entity structures to ensure we can successfully operate as a REIT as of January 1, 2014.

New Multi-Year Strategic Plan

        In the third quarter of 2013, the senior leadership of the Company developed our The Strategic Plan and identifiedincludes three core pillars that will drive our business strategy for the next several years. The table below highlights key milestones the Company has already achieved inidentifies each of the threecore pillars of our Strategic Plan:and highlights the key milestones achieved in 2014 with respect to each core pillar:

Pay and Performance AlignmentProgram Design Changes

        OurIn connection with the execution of the Strategic Plan, the Compensation Committee appliesapproved a pay for performance philosophy, which is reflectedseries of changes in (1) the actual 2013 payouts made pursuant2014 to our incentiveexecutive compensation programs to better align our incentives with our short- and (2)long-term strategic objectives and better align our rewards with the designcreation of stockholder value.

•

2014 changes to our short-term incentive program approved by the Compensation Committeeinclude:



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basing our 2014 short-term incentive opportunity, which is common to our entire senior executive team, on a combination of financial and strategic objectives designed to further align our payouts with our strategy objectives.

the senior executive team toward execution of company-wide goals2013 Performance & Compensation Earned



•

        During 2013, our reported results were consistent with our external guidance. Althoughtying 70% of the 2014 short-term incentive target bonus to achievement of enterprise revenue and Adjusted OIBDA⁽¹⁾⁽²⁾ were consistent, with our guidance range, our operational performance generally did not reachincreased payout opportunity when revenue exceeds target levels



•

tying 30% of the goals established by our Compensation Committee for a 100% payout under our2014 short-term incentive programs. Our enterprise revenue was below our incentive plan goal, achieving 98.3% of our target and our ROIC⁽²⁾ was below our incentive plan target, achieving 9.82% against a target of 10.06% due primarilybonus to the accelerationachievement of capital expenditures from 2014 into 2013;strategic objectives, including:





•

specific objectives for each of the three core strategic pillars, intended to measure interim progress toward the multi-year goals;

⁽¹⁾

Emerging markets include central and eastern Europe, Latin America and the Asia Pacific region (excluding Australia and Singapore).

⁽²⁾

Adjusted OIBDA is defined as operating income before (1) depreciation, and amortization, (2) intangible impairments, (3) (gain) loss on disposal/write-down of property, plant and equipment (excluding real estate), net and (4)REIT costs, which include costs associated with our 2011 proxy contest,conversion to a REIT, excluding REIT compliance costs beginning January 1, 2014 which we expect to recur in future periods. For the workpurposes of our short-term performance-based incentive plan, Adjusted OIBDA targets and results are measured prior to the impact of severance expenses.

•

operating within REIT qualification requirements; and



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talent development to support execution of the former Strategic Review SpecialPlan



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retaining the opportunity for individual differentiation through the use of a modifier for individual performance



•

2014 changes to our long-term incentive program include:



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rewarding the achievement of growth objectives in conjunction with our Strategic Plan



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enhancing our portfolio of vehicles to reward the achievement of certain objectives with:



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multi-year PUs, the achievement of which is measured relative to total 2016 revenue and 2016 ROIC⁽³⁾, or the ROIC PUs;



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multi-year PUs, the achievement of which is a measurement of total stockholder return, or TSR, performance relative to the majority of S&P 500, or the TSR-Based PUs (which, together with the ROIC PUs, are referred to herein as the PUs), which have been granted to our CEO and which the Compensation Committee has granted to the other Named Executive Officers beginning in 2015;



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setting our CEO's 2014 long-term incentive to be 60% performance-based, utilizing 30% PUs (including TSR-Based PUs) and 30% premium-priced stock options, which were set with an exercise price of 125% of the fair market value on the date of grant;



•

2014 changes to our Executive Stock Ownership requirements include:



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increasing the ownership requirements to further align our executives' interest with those of our board of directorsstockholders as follows:

•

The 2014 Plan was approved by stockholders in January 2015, and the proposedperformance measures available under the 2014 Plan to meet the performance-based exclusion under Section 162(m) of the Internal Revenue Code of 1986, as amended, or the Code, were expanded to include measures common to REITs.

2014 Performance & Compensation Earned

        Our operational performance, after adjusting for the impact of acquisitions during the year, exceeded the goals established by our Compensation Committee. Adjusted OIBDA was 101.8% of target, reflecting our focus on continuous improvement. Our enterprise revenue, however, was slightly below our incentive plan goal, achieving 99.7% of our target. Our performance against our strategic objectives, on average, exceeded the goals established by the Compensation Committee. Our TSR was approximately 49.3% relative to 13.7% for the S&P 500 Total Return Index, reflecting the impact of our conversion to a REIT conversion.during 2014 as well as our operational performance.

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ROIC is defined as net operating profit after taxes plus depreciation and amortization less non-growthnon growth capital expenditures divided by the average of the beginning and ending balance of total debt plus stockholders equity and non-controlling interest less cash plus accumulated depreciation on racking.

however, Adjusted OIBDA was 100%        Consequently, due to our pay-for-performance design and as a result of target, reflecting our focus on cost management. In addition, our TSR was approximately 1.0% during 2013. Consequently, with our pay forstrong performance design,in 2014, our variable compensation programs delivered belowabove target rewards during 2013,2014, and our CEO'sMr. Meaney's multi-year award isawards are tracking below target:at or above target. Payout and progress results for 2014 include:

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short-term incentive awards, on average, achieved 89.5%125.85% of target;



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PU awards granted in 2013 using Revenue and ROIC performance measures earned 70% ofMr. Meaney's TSR-Based PUs are tracking at or above target and will vest in March 2016;levels:



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Mr. Meaney's TSR-based PU award is tracking2013 TSR-Based PUs are forecast at a payout of 0%102% of target as of December 31, 2013 based on our relative TSR performance at the 7th percentile. The final payout may differ based on TSR performance between51^st percentile for the two-year period ending December 31, 2013 and December 31, 2015;2014; and



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Mr. Meaney's 2014 TSR-Based PUs are forecast at a payout of 200% of target based on our relative TSR performance at the 96^th percentile for the year ended December 31, 2014.

        Based on our strong TSR in 2014, the potential value of our executives' outstanding equity awards were madehas increased commensurate with the value delivered to our executivesstockholders in March 2013, when our share price was $36.25, but our year-end share price was $30.35; therefore, the current value of those equity awards is significantly below the grant value.

2013 Program Design

        Except for the TSR-based PUs awarded to Mr. Meaney, the Compensation Committee made no changes in 2013 to the performance measures used in our short-term incentive program or the performance unit component of our long-term incentive plan because the Committee determined those measures appropriately supported our strategic goals.

        The Compensation Committee determined that Mr. Meaney's short-term incentive payout in 2013 should be based 50% on financial objectives and 50% on individual objectives. The Compensation Committee also determined that assigning 50% of Mr. Meaney's short-term incentive payout to individual objectives, compared to 25%-33% for other Named Executive Officers, was appropriate for 2013 due to Mr. Meaney's focus on internal and stockholder engagement, due to his directive to develop and begin to implement our Strategic Plan and given that he was not principally involved in the development of the 2013 budget. The additional focus on individual objectives applies only for 2013 and will align with other Named Executive Officers in 2014.

2014 Program Design

        The Compensation Committee has approved a number of changes to our short-term and long-term incentive programs in 2014 to better align our incentives with the long-term goals of our Strategic Plan and to better align rewards with those of our stockholders. The changes are intended to reflect the following objectives:

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provide greater incentive for profitable revenue growth while continuing to drive strong ROIC performance;



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provide rewards for attainment of key strategic initiatives that support revenue growth; and



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provide incentives for both total stockholder return and absolute share price appreciation.

        Specific detail regarding the changes in our incentive programs can be found under the heading "2014 Program Changes."

Say-on-Pay Vote Response and Stockholder Engagement

        We have an annual stockholder advisory vote on executive compensation, a "say-on-pay" vote, to provide stockholders with an additional tool to voice their opinions about executive compensation, with a goal of maintaining an alignment of interests between our stockholders and our executives. The Compensation Committee considered the results of the advisory vote by stockholders on the "say-on-pay" proposal presented to stockholders at the Company's 20132014 Annual Meeting of

Stockholders. As in 2012,previous years, there was overwhelming support at the 20132014 annual meeting for the compensation program offered to the Company's Named Executive Officers, with approximately 99%98% of votes cast in favor. Accordingly, in 2013,2014, the Compensation Committee made no direct changes to the Company's executive compensation programs as a result of the say-on-pay vote at the Company's 20132014 Annual Meeting of Stockholders.

        Our executive compensation programs reflect a number of best practices implemented by the Compensation Committee in recent years, including:

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compensation clawback policy;



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executive and director stock ownership requirements, which exclude unvested and unearned shares, including a requirement to retain certain shares until the requirement is met (with shares of Common Stock that are held in margin accounts or otherwise pledged sharesto secure loans not counting towards meeting the requirement);



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between 70%69% and 84% of our executive officers' target direct compensation is at-risk;



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"double trigger" feature, requiring both a change in control and termination of employment before the acceleration of vesting of awards granted under both the 2002 Plan and the 2014 Plan;



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our Compensation Committee retains an independent compensation consultant;



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we do not offer excise tax gross-ups in connection with a change in control;



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we do not offer pensions or supplemental executive retirement plans; and



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limited use of executive perquisites.perquisites that recognize standard local practices in international markets.

        In late 2013, the Company's management conducted outreach with certain stockholders related to our executive compensation. Even though we have received significant support from stockholders through our say-on-pay votes, the Company and our Compensation Committee felt it was important as they reviewed our compensation design and considered changes for 2014 to engage directly with our stockholders in order to gain a better understanding of our stockholders' views on our executive compensation practices. We ultimately engaged with stockholders representing 39% of our outstanding shares, and the stockholders with whom we communicated reiterated their support for our approach to executive compensation while sharing their perspective on what they most value in executive compensation programs. The findings were reported to and considered by our Compensation Committee as they evaluated and adopted the 2014 program changes.

Compensation Philosophy and Design Principles

        The purpose of our executive compensation programs is to attract, retain and focus the talents and energies of executives, including our Named Executive Officers, on meeting the current and future objectives of the Company, most notably the creation of stockholder value. The design principles that govern our Named Executive Officer compensation programs are described below.

        General program competitiveness—Our compensation program serves to attract and retain top performing executive officers. All of our executive compensation program target pay levels are established with reference to relevant market data to evaluate their competitiveness. In evaluating external market data, we analyze the 25^th, 50^th and 75^th percentiles as appropriate frames of reference. The relative position of each Named Executive Officer's compensation compared to the market data referenced reflects his or her experience and proficiency in performing the duties of his or her position.

        Pay for performance—A substantial percentage of each Named Executive Officer's total compensation opportunity is contingent on annual and multi-year performance. Total incentive compensation can exceed the awards' target award level if performance exceeds the target. Conversely, if performance does not achieve the

target, total incentive compensation can fall below the awards' target award level and be as low as zero. Performance in our incentive compensation program is defined as:

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annual business unit and/or enterprise financial performance against pre-established objectives, which in 20132014 were revenue and Adjusted OIBDA;



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multi-year performance against pre-established objectives, which in 2014 were revenue growth, Adjusted OIBDA and ROIC;ROIC, each as measured in 2016 as the final year of a 3-year performance period;



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stock price appreciation, which increases the value of equity compensation awards, including stock options, RSUs and PUs; and



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the demonstrated ability of each member of the Senior Executive Team and each Named Executive Officer's demonstrated abilityOfficer to develop and execute individual initiatives designed to help us to achieve our strategic objectives, builddevelop talent and capabilities essential to the long-term success of the business and demonstrate our established leadership behaviors.behaviors consistent with Company values.

        Internal parity—EachThe total compensation opportunity for each Named Executive Officer's total compensation opportunityOfficer reflects the responsibility, scope and complexity of that individual's role within the Company.

        Stockholder alignment—Our compensation programs for our Named Executive Officers align with the interests of our stockholders by emphasizing performance criteria that drive both short-term results and long-term stockholder value creation. Our long-term incentive compensation program awards equity to our Named Executive Officers, and in 2013 all Named Executive Officers had minimum share ownership requirements of one times base salary or, in the case of our CEO, three times base salary. Effective February 2014, the minimum share ownership requirements were increased to five times base salary for our CEO, three times base salary for our CFO and two times base salary for all other Named Executive Officers.

        Alignment with various business strategies—OurBeginning in 2014, we structured our executive compensation programs are structuredprimarily to be flexible in recognizing that individuals within functionsprovide common rewards for the achievement of enterprise financial goals and strategic objectives. Our annual short-term incentive program continues to provide for individual differentiation reflecting each executive's responsibility for the performance of such executive's function's or business units must focus on specific financial measuresunit's contribution toward the common goals, and such executive's bonus may be adjusted according to meet the short-term and long-term plans of the functions or business unit for which they are accountable. In addition, each executive leads strategic initiatives specific to the functions or business units for which he or she is responsible, and the success metrics for those initiatives will vary. Thus, it is possible for certain functional or business unit leaders to earn substantial awards in years when their function or business unit outperforms the Company as a whole. Conversely, if a function or business unit fails to meet its objectives, the executive responsible for that function or business unit may earn a lesser award in that year than his or her peers in a function or business unit that met or exceeded its goals.achievement versus individual objectives.

Establishing Compensation

Process

        In applying our compensation philosophy and design principles to establish appropriate compensation programs and target compensation levels, our Compensation Committee:

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Annually approves a recommendation to the Board for the salary, short-term and long-term incentive compensation for our CEO. The Compensation Committee's recommendation reflects (1) an analysis of the Company's performance against predetermined financial goals and its evaluation of our CEO's performance against predetermined individual objectives and (2) input from members of the Board and senior management.Board. The Compensation Committee's recommendation is then presented to the independent members of the Board for approval. The Board approval contains an automatic adjustment mechanism to account for changes in the final audit report, and any such adjustment is presented to the Compensation Committee for certification.



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Annually reviews and approves the salary, short-term and long-term incentive compensation for our other Named Executive Officers.

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Annually reviews and approves the structure of our short-term and long-term incentive programs for all Named Executive Officers, including performance metrics, performance and payout grids and the weighting applied to each metric. The review typically balances an internal and external perspective developed in collaboration with members of management and the Compensation Committee's compensation consultant. Based upon this review, the Compensation Committee may maintain or modify the amount and mix of grants under our incentive programs.



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Annually establishes the individual goals and objectives utilized in our short-term incentive program for our CEO and reviews the individual goals for the other Named Executive Officers recommended by our CEO.



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Periodically evaluates the effectiveness and competitiveness of other executive compensation programs, such as executive benefits, perquisites and our severance policies. These periodic evaluations are conducted to ensure alignment with our internal strategy and objectives and to consider external market practices.



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Annually establishes the financial performance goals that are utilized in our short-term and long-term incentive plans. The annual financial performance targets are initially based upon our annual operating plan approved by our Board, assuming constant currency, and may be adjusted during the year. The multi-year performance targets are aligned with achieving our Strategic Plan. When the financial targets are set, the Compensation Committee approves a policy which identifies the nature of potential adjustments to the target levels that willmay be considered throughout the fiscal year. On a quarterly basis, ourOur internal audit team reviews the potential adjustments and reports the results to our Audit Committee. The Compensation Committee considers this reportthese reports and may adjust financial targets based on the adjustment factors approved at the beginning of the year.

        In 2013,2014, the Compensation Committee approved adjustments to performance goal targets or actual results to eliminate the effects of unbudgeted acquisitions and, large unanticipated or uncontrollable events unrelatedfollowing our decision to current management performance,elect REIT status as of January 1, 2014, the ongoing REIT compliance costs, or the Adjustment Factors. IncludedThe Adjustment Factors apply to all compensation awarded in the unanticipated or uncontrollable events portion2014 that is subject to performance goals.

        The net effect of applying the Adjustment Factors were restructuring charges associated withto the realignmentrevenue target increased the target by 0.8%. The net effect of our organizational structure that we recorded inapplying the third and fourth quarters of 2013 and increased investment in emerging businesses duringAdjustment Factors reduced the year.Adjusted OIBDA target by 1.4%.

        Prior to 2013,2014, the Compensation Committee had approved a process where our performance goal targets would be automatically adjusted if paper prices fluctuate outside of a pre-approved range. For 2013,In 2014 paper prices remained within the pre-approved range; consequently, no adjustment was made. The Adjustment Factors apply to all compensation subject to the respective performance goals.

        The net effect of applying the Adjustment Factors to the respective revenue targets increased the target between 0.7% and 2.65%. The international target was most impacted due to its relative size with a 2.65% increase while the enterprise target increased 1.3% and the North American target increased by 0.7%. The net effect of applying the Adjustment Factors reduced the Adjusted OIBDA results between 1.5% and 2.35%. Enterprise results were reduced by 2.35% while international and North America were each reduced approximately 1.5%.

Role of Named Executive Officers

        Our Named Executive Officers assist the Compensation Committee in carrying out its duties throughout the year by completing specific tasks, including:

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our CEO establishes the individual goals and objectives for the Named Executive Officers (other than himself). He proposes his own individual goals and objectives, with input from the Board, which are then approved by the Compensation Committee;

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our CEO develops compensation recommendations for the Named Executive Officers (other than himself) for the Compensation Committee's review, including salary levels, economic value of long-term incentives and achievement of individual goals and objectives; and



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each Named Executive Officer prepares a self-review to assist the review of his or her performance against individual goals and objectives, which self-review is shared with the Compensation Committee for the CEO and with the CEO for the other Named Executive Officers. The other Named Executive Officers provide feedback on the CEO's performance to the Compensation Committee to assist in the evaluation of the CEO's performance.

Benchmarking

        To provide an external perspective relative to executive compensation levels, plan design trends and market best practices, the Compensation Committee reviews market analyses prepared by its independent compensation consultant. Given the nature of our business and our market leading position, there is no ideal group of companies that reflects direct business competitors or competitors for talent. The Compensation Committee has elected to develop a group of business services companies, or the Custom Peer Group, to serve as a reference point for the market analyses.

        The Compensation Committee, in collaboration with our compensation consultant and management, annually reviews the Custom Peer Group for continued applicability and has developed the Custom Peer Group below based on the following criteria:

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comparable size and industry;



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similar market capitalization; and



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similar degree of global operations.

        The 20132014 Custom Peer Group includes the following companies, with an asterisk notingwhich is unchanged from the newly added company:2013 Custom Peer Group:

        The median 20112012 revenue of the Custom Peer Group was $2.8$3.3 billion, compared to the Company's 20112012 revenue of $3.0 billion. The 2013 Custom Peer Group, as compared to the 2012 Custom Peer Group, reflects the removal of Crown Castle, Moody's, Teradata and Unisys due to the fact that those companies operate in different industries and the addition of Clean Harbors.

        For 2013, there was insufficient data within the Custom Peer Group from which to benchmark Ms. Drapeau's role as executive vice president, strategy and talent. While a direct match to Ms. Drapeau's responsibilities was not available, a general industry analysis was conducted based on similarly sized organizations to serve as a market reference for Ms. Drapeau's compensation.

How We Use Market Data

        Pay levels—Market data is one element considered by the Compensation Committee when making compensation decisions, but the Compensation Committee does not set compensation levels based solely on market data. Rather, the Compensation Committee reviews the 25^th, 50^th and 75^th percentiles of relevant market data as one frame of reference in making its compensation decisions. Final compensation decisions reflect a variety of factors, including each executive's experience, performance

rating, the relative importance of the executive's role within the organization, as well as where theeach executive's pay level falls relative to the market data.

        Plan design—When designing or assessing the design of our compensation programs, the Compensation Committee reviews programs of the Custom Peer Group to establish typical market practice. The Compensation Committee evaluates our specific circumstances and business objectives and follows market practice with respect to the design of our programs where appropriate but may deviate from market practice where the Compensation Committee deems it is in the best interest of the Company and our stockholders.

Role of Consultants

        The Compensation Committee has retained the services of an independent compensation consultant to provide ongoing advice and perspective to the Compensation Committee in the following areas related to the compensation of our Named Executive Officers:

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market pay analyses and market trends;



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assistance with the review and selection of the Custom Peer Group;



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ongoing support with regard to the latest relevant regulatory, technical and/or accounting considerations affecting compensation and benefit programs;



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assistance with the design of executive compensation or benefit programs, as needed; and



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preparation for and attendance at selected Compensation Committee meetings.

        Since May 2012, the Compensation Committee has engaged Pay Governance LLC, or Pay Governance, to assist the Compensation Committee by providing ongoing executive compensation consulting. Pay Governance reports directly to the Compensation Committee and has regular meetings with the chairperson of the Compensation Committee.

        Pay Governance does not provide any other services to the Company except providing assistance on director compensation matters for the Nominating and Governance Committee. The Compensation Committee has reviewed the nature of the relationship with its independent compensation consultants and determined that there were no conflicts that impacted the advice and guidance provided to the Compensation Committee.

Components of Compensation

        Our Named Executive Officers' total direct compensation, or TDC, is designed to reward our executivesNamed Executive Officers based on achievement of financial and strategic goals and returns to stockholders and consists of base salary, target bonus and long-term incentive grant value. Mr. Meaney's compensation includes a majority of the components from the TDC program but also includes variations that the Compensation Committee approved in connection with Mr. Meaney's new hire compensation. The components of Mr. Meaney's compensation are detailed in the "CEO Compensation" section below.

        As depicted below, approximately 70%69% to 84% of our Named Executive Officers' target TDC is tied directly to the achievement of financial goals, strategic objectives or stock price appreciation through our short-term and long-term incentive programs. For example, excluding the value of his new

hire inducement award, approximately 85% of Mr. Meaney's $6.25 million target TDC, or $5.25 million, was at-risk when granted.

CEO (Excludes New Hire Long-Term Incentive Value)		Other Named Executive Officers

        Below is a summary of the elements, objectives, risk mitigation factors and key features of our TDC program for our Named Executive Officers. A more detailed discussion of each element and the associated pay decisions follows this section.

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Base salary and benefits are designed to attract and retain highly qualified individuals. Inindividuals; in order to avoid excessive risk taking, it is important that not all cash compensation be variable.



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Annual cash short-term incentive compensation awards forare designed to focus the entire senior executive team, including the Named Executive Officers, are designed to focus these individuals on:toward achieving enterprise goals while recognizing their individual contributions, including:



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attaining financial goals in line with our annual budget;



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achievement of strategic objectives;



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performance relative to initiatives in areas within their control; and



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rewarding outstanding individual performance.



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Our short-term incentive awards are expressed as a percentage of base salary, and the amount of compensation payable under each award is subject to a maximum payout. Short-termpayout; short-term incentive awards are also subject to our clawback policy described below under the "Executive Compensation Clawback."Clawback" section of this Proxy Statement.



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Long-term equity incentives are designed to:



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align the interests of our Named Executive Officers with our stockholders;



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reward overall enterprise performance; and



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encourage the retention of the Named Executive Officers by providing additional opportunities for them to participate in the ownership of the Company and its future growth.



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Our long-term incentive awards are granted in the form of PUs, RSUs and RSUs.stock options. Generally, PUs are subject to cliff vesting three years from the date of the original grant and settle in shares of our common stock. RSUs and stock options typically vest ratably over three years (with certain exceptions described below) and are settled in shares of our Common Stock. RSU and PU

Equity awards are also subject to our clawback policy described below underthe "Executive Compensation Clawback."Clawback" section of this Proxy Statement.

        In addition to the TDC elements described above, our U.S.-based executives participate in the retirement and welfare benefits generally available to our full-time employees, such as medical, dental,

life insurance, 401(k) Plan, the 2013 ESPP, and other fringe benefits, some of which are more fully described below:

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our 401(k) Plan allows our Named Executive Officers to contribute up to 25% of their "plan" compensation, subject to certain regulatory limits. Under our 401(k) Plan, we generally match 50% of the first 4% of compensation contributed by our Named Executive Officers, up to $5,100$5,200 for 2013. Non-highly compensated employees are eligible for matching contributions of 50% up to the first 5% of compensation contributed, up to $6,375 for 2013. Due to IRS rules, newly hired executives are considered non-highly compensated employees in their first year of employment.2014.



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the 2013 ESPP provides all of our employees in the U.S. and Canada with the opportunity to acquire an equity interest in the Company by providing favorable terms upon which they may purchase our Common Stock.

        In addition, our U.S.-based Named Executive Officers are eligible for certain executive benefits, including a voluntary deferred compensation program and limited perquisites, which are included in the "All Other Compensation" column of the "Summary Compensation Table" and related footnote.footnote appearing in this Proxy Statement.

        Also, our Executive Deferred Compensation Plan, or the EDCP, allows our Named Executive Officers to defer some of their base salary and/or cash incentive compensation in amounts in excess of the amounts they can defer under our 401(k) Plan. The Company does not provide contributions under the EDCP. The EDCP is intended to encourage the continued employment of the participating employees who are largely responsible for our success, and to facilitate the recruiting of executive officers and other highly compensated employees required for our continued growth and profitability. Mr. Duale and Mr. Day do not participate in the 401(k) Plan, the 2013 ESPP or the EDCP, but each receives additional benefits that are customary for executives in their respective work locations as more fully discussed under the "—Employment Agreement with Mr. Duale" and "—Employment Agreement with Mr. Day" sections of this Proxy Statement.

CEO Compensation

        As described above, the Company entered into the CEO Offer Letter with Mr. Meaney pursuant to which Mr. Meaney became our CEO, effective January 7, 2013, and received an annual TDC target of approximately $6.25 million, plus one-time awards of approximately $2.25 million. The specific components of the CEO Offer Letter include:

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Annual base salary of $1.0 million, which may be increased in connection with the Company's annual compensation review process. Mr. Meaney's annual base salary is paid partially in the form of 100,000 Swiss Francs to his address in Switzerland and the remainder in U.S. dollars to his address in the United States;



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A signing bonus of $250,000;



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Target annual cash short-term incentives equal to 125% of base salary; and



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An initial long-term incentive package totaling $6.0 million, primarily based on the Company's performance ($4 million in annual grant value, $2 million one-time new hire award value). The initial $6.0 million long-term incentive package was delivered in $2.0 million awards in each of

PUs, RSUs and stock options. The structure of each award and the rationale for each component of the long-term incentive package is detailed in the table below:

        We agreed to pay Mr. Meaney a portion of his salary in Swiss Francs because Mr. Meaney is a Swiss citizen and he works a portion of his time in Switzerland related to his responsibilities associated with the significant international focus of the Company. As part of the CEO Offer Letter, the Company also agreed to reimburse Mr. Meaney for the cost of his Swiss medical insurance.

        In December, 2013, in order to implement the agreement between the Company and Mr. Meaney with respect to the payment of a portion of Mr. Meaney's base salary in Swiss Francs, a Swiss subsidiary of the Company entered into an employment agreement with Mr. Meaney. As required by Swiss law, the Company, through such Swiss subsidiary, will fund certain benefits on Mr. Meaney's behalf in connection with his Swiss employment, including an occupational benefit plan contribution and occupational accident insurance. The Company's contribution levels reflect amounts required by Swiss law and are quantified in the "Summary Compensation Table."

        Mr. Meaney is eligible to participate in the Company's benefits program generally available to its senior executives which are described in the section above. In 2013 Mr. Meaney participated in our international medical plan because his family was located in Hong Kong for a portion of the year. In connection with his relocation from Hong Kong to the Company's headquarters in Boston, Massachusetts, Mr. Meaney was eligible for a relocation allowance through our senior executive relocation program (not to exceed $600,000, inclusive of any applicable tax gross-ups).

        Occasionally, members of Mr. Meaney's family have accompanied him on business travel when it is necessary. Travel provided or paid for by the Company is taxable to Mr. Meaney, and the Company provides a gross-up due to the business nature of the travel. For commercial flights, the cost paid by the Company along with the associated tax gross-up is included in the "Summary Compensation Table." For private flights, there is no incremental cost to the Company, but Mr. Meaney is subject to taxation. Therefore, the "Summary Compensation Table" includes the tax gross-up associated with the imputed income attributable to Mr. Meaney in connection with private flights.

        Mr. Meaney is also eligible for the Iron Mountain Companies Severance Plan, as described in the "Severance Policy" section of this Proxy Statement, with the following adjustments: in the event Mr. Meaney terminates his employment for good reason or is terminated by the Company for other than cause in connection with a change in control, he will be eligible for two years' salary and target bonus (rather than one year) and eighteen months of group health benefit continuation (rather than twelve months).

Base Salary

        The table below details the annualized salaries at the end of each year of our Named Executive Officers and the increases from 20122013 to 2013,2014, where applicable, which were effective in March 2013.2014. Consistent with typical market practice, in 20132014 our CEO received a higher base salary than the other Named Executive Officers. This is due primarily to the greater responsibility, experience and oversight duties of the CEO as compared to the other Named Executive Officers.

        The increase provided to Mr. Day reflects his performance in his role as chief financial officer, International prior to assuming the role of interim chief financial officer of the Company. The increase provided to Ms. Drapeau primarily reflects her increase in responsibility for corporate strategy in addition to her existing responsibility for human resources.

        The decrease in Mr. Reese's salary is due to his transition from CEO and Executive Chairman to special advisor to the Company.

        Despite their excellent ratings in our internal performance evaluation process, the salary of each of Messrs. Cloutier, Duale, EbbighausenTomovcsik and McKeonMeaney remained unchanged in 2013.2014. The Compensation Committee determined that the salary of each of Messrs. EbbighausenCloutier, Tomovcsik and McKeonMeaney was appropriately positioned based on the factors considered by the Compensation Committee and that any increases in compensation were more appropriately delivered through our variable compensation programs.Committee. Mr. Duale's base salary is positioned at the 75th percentile of market data, largely due to his depth of experience in leading international businesses prior to joining the Company, and reflects the compensation that was necessary to entice him to join the Company. Mr. Duale's salary has not been increased since 2009 in recognition of his position relative to both external market data and internal parity.

        The base salary increase provided to Mr. Day reflects his expanded responsibilities after his appointment to chief financial officer of the Company in March 2014.

Short-Term Performance-Based Incentive Compensation

Target Incentives

        Our Named Executive Officers participate in the Company's short-term performance-based incentive compensation programs. The Compensation Committee annually reviews the target short-term incentive opportunity for each Named Executive Officer and approves a new target, when appropriate.

Short-term incentive compensation opportunities are expressed as a percentage of each Named Executive Officer's base salary. For 2013,2014, these percentages were:

        The targetpercentage of Mr. Tomovcsik's 2014 salary attributable to short-term incentive compensation opportunitiesopportunity was set at 70% in connection with his promotion to EVP & GM, Records & Information Management in January 2014.

        The percentage of 2014 salary attributable to short-term incentive opportunity for ourthe other Named Executive Officers for 2013 areis, in each case, unchanged from 2012 because the2013. The Compensation Committee determined thethat each target opportunity represented the appropriate amount of short-term compensation at risk for each Named Executive Officer based on his or her role, impact on the Company's results and market comparisons. In 2013,2014, Mr. Meaney's target opportunity was the largest among the Named Executive Officers because he was most accountable for the Company's performance, and the Compensation Committee determined it was important to provide a greater portion of his cash compensation through a variable program. The target short-term incentive compensation opportunity for other Named Executive Officers is a lower percentage of their base salary, reflecting their mix of compensation, expected impact on the performance of the Company and market practice for their role. Mr. Day's target short-term incentive compensation opportunity was established in his role as chief financial officer, International and was not changed when he assumed the role of interim chief financial officer of the Company.

Program Structure

        In 2014, the Compensation Committee approved changes to our short-term incentive program design that are intended to better align our incentives with the objectives of our Strategic Plan. Achievement of the target short-term incentive opportunity is based upon (1) the Company's performance against targetedtarget financial goals, (2) Company performance against a series of strategic objectives and (3) personal performance against the individual goals and objectives of the respective Named Executive Officer set at the beginning of the year. In addition, short-term incentive compensation for ouryear, as illustrated below. All members of the senior executive team, including the Named Executive Officers, (excepthave the same target financial goals and the same financial and strategic objectives, which serve to align the senior executive team toward the same enterprise goals. The individual modifier component, however, allows for Messrs. Dayrecognition of individual performance and Duale) may be increased by up to 125% for corporate overachievement, or the Corporate Modifier, as illustrated below.contributions. In support of our philosophy of paying for performance, actual short-term incentive awards for our Named Executive Officers may range from 0% to 156.25% of their targets, including the application of the Corporate Modifier.

        Mr. Day's short-term incentive compensation is determined under our international bonus program in his role as chief financial officer International. Under the international bonus program, Mr. Day's short-term incentive payout is measured against our International business unit financial performance, and the payout ranges from 0% to 130% of his target opportunity, as opposed to 0% to 100% for our other Named Executive Officers (other than Mr. Duale). The International business unit financial performance is measured differently from enterprise and North America financial performance because there is greater volatility in emerging markets and because over-performance in the Internationala

portfolio may notmaximum of 167.5%, which can be captured in the measures of enterprisereached when achieving maximum performance due to the International portfolio's relative size. Mr. Day is not eligible for the Corporate Modifier for any portion of his short-term incentive compensation because the international bonus program allows for payouts in excess of 100%against all measures.

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70% of the short-term incentive target bonus is based on the Company's financial performance, measured by enterprise Adjusted OIBDA, with increased payout opportunity when revenue exceeds the target level. Payouts of this component of the short-term incentive bonus may range from 0% - 150% of target, and more directly rewards forthe highest payouts are possible only when both enterprise Adjusted OIBDA and revenue exceed the budget approved by the Board. We believe this measure appropriately corresponds to our profitable growth objectives.



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30% of the short-term incentive target bonus is based on the achievement of goals specific strategic objectives which are intended to our Internationalmeasure progress toward achievement of the multi-year objectives of the Strategic Plan. Payouts of this component of the short-term incentive bonus may range from 0% - 125% of target, and the strategic objectives that comprise this component include specific measures in the following areas:



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cubic volume growth in developed markets;



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revenue growth in emerging markets;



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the development of a robust emerging business segment. pipeline;



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operating within REIT qualification requirements; and



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talent development.



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In addition, the internationaleach executive's short-term incentive bonus program accounts for the relative volatilitymay be increased or decreased by as much as 25% of the International business, compared to North America and enterprise, by increasing the minimum payout for threshold financial performance to 50% (versus 4% for enterprise and North America).

        Mr. Duale is subjecttarget based on such executive's contribution to the samemeasures above and performance and payout ranges as Mr. Day for the portion of his short-term incentive measured relative to the performance of the International business unit. Similarly, For Mr. Duale, the Corporate Modifier does not apply to the portion of his short-term incentive measured relative to our International business unit financial performance.

        For 2013, revenue and Adjusted OIBDA were chosen as the financial performance measures for all Named Executive Officers because the Compensation Committee determined those items were appropriate measures of the achievement of our profitable growth objectives. Theagainst specific individual goals and objectives, component of the Named Executive Officers' short-term incentive opportunity includedincluding items such as the development and execution of business, organizational and marketing strategies with the objective to increase revenue and Adjusted OIBDA. Mr. MeaneyOIBDA and Ms. Drapeau, due to the broad enterprise focus of theirprogress toward our multi-year strategic objectives, have a greater portion of their short-term incentive opportunity tied to individual goals and objectives than Messrs. Duale and Ebbighausen. Mr. Day's mix of financial and individual goals reflects his expected impact on our International business segment. The specific weight applied to the financial performance measures and the individual goals of the Named Executive Officers is detailed in the "Payouts of Short-Term Incentive Compensation" table below.

objectives.

Financial Performance

        The portion of each Named Executive Officer's short-term incentive opportunity tied toPerformance against financial targets related to the segment in which he or she operated. For Mr. Meaney and Ms. Drapeau, final payout determinations are measured2014 was determined based on the enterprise financial results. Messrs. Day's, Duale'smatrix below. In developing the matrix, the Compensation Committee sought to first ensure achievement of Adjusted OIBDA targets and Ebbighausen's payout determinations are measured based onthen reward overachievement when both revenue and Adjusted OIBDA exceed target levels. The Compensation Committee selected a maximum payout of their respective business units,150% of target to be consistent with market practice but structured the matrix such that maximum payout was achieved only when revenue and Messrs. Duale's and Ebbighausen's payout determinations also includeAdjusted OIBDA exceeded levels that the revenueCompensation Committee considered

exceptional performance based on the difficulty of the enterprise. Our objective is to focus the entire team on achieving financial goals that are aligned.

        For enterpriseannual operating plan and the North American business unit, no payout is earned unless the threshold is achieved, which, in the case of revenue, is 97% of target and, in the case of Adjusted OIBDA, is 95% of target. For the enterprise and the North American business units, the table below details specific financial goals and actual 2013 results for each financial performance metric.recent Company performance.

        For 2014, the International business unit, noNamed Executive Officers achieved 109% payout is earned unlessof the threshold is achieved, which, inshort-term incentive target bonus based on the case of revenue and Adjusted OIBDA, is 95% of target, and the maximum payout is earned at 105% of target. The specific financial goals and actual 2013performance results are detailed below.below:

Strategic Objectives

        The table below describes the specific key measures established in 2014 for each of the five strategic objectives on which the short-term incentive target bonus is based. The Compensation Committee weighted each strategic objective equally and, for the purposes of determining payout, the Compensation Committee selected the key measures described in the table below as most representative of reflecting progress toward our broader strategic objectives. In establishing the payout opportunity for each of the goals, the Compensation Committee sought to set threshold performance levels for 2014 that demonstrated progress toward the multi-year goals. The Compensation Committee

provided increasing rewards as performance approached the maximum level to recognize overachievement relative to expected progress during the year.

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For purposes of the strategic objectives, emerging markets also include Switzerland, Austria and Singapore which were reclassified to developed markets after the goals were established in February 2014.

        Overall, the Company achieved 108.5% of the specific strategic objectives target for 2014 based on the strategic objective results below:

Individual Goals and ObjectivesModifier

        Individual goals and objectives were aimed at focusing each Named Executive Officer's attention in areas where that officerhe has the most potential for impacting the Company's performance, and we believe theseeach Named Executive Officer's targets were reasonably attainable if the Named Executive Officershe performed to theirhis potential.

        Each of the Named Executive Officers metexceeded his or her 20132014 individual goals and objectives.objectives, and the Compensation Committee approved a specific positive individual modifier for each Named Executive

Officer. The table below includes the key factors considered in evaluating the achievement of each Named Executive Officer's individual goals and objectives:

Corporate Modifier

        In addition, as a result of the Corporate Modifier, the entire short-term incentive payment for all Named Executive Officers (other than Messrs. Day and Duale) can increase over the target opportunity if the Company exceeds the enterprise Adjusted OIBDA target for the fiscal year (as described earlier, Mr. Day's bonus is not eligible for the Corporate Modifier and the Corporate Modifier only increases the portion of Mr. Duale's short-term incentive payment that is based on enterprise revenue and individual performance). As shown in the table below, exceeding the enterprise Adjusted OIBDA target allows for a Corporate Modifier of up to 125% of the total payout as determined by the performance against targets and goals described above. The Corporate Modifier is formula-based and, while the table below illustrates the key overachievement points and the corresponding multiplier, points are interpolated between those shown in the table. The 2013 performance did not exceed the Adjusted OIBDA target and, therefore, did not generate a Corporate Modifier.

        Based on our 20132014 achievement relative to established financial goals, strategic objectives and individual goals and objectives, our executivesNamed Executive Officers earned 89.5%125.85% of target short-term incentive opportunity, on average. The following table sets forth certain information relating to the payouts of short-term cash incentive compensation to the Named Executive Officers during the year ended December 31, 2013.

2014.

Payouts of Short-Term Incentive Compensation