Iron Mountain 8-K 2026-05-07

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 8-K

CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

Date of report (Date of earliest event reported): May 7, 2026

IRON MOUNTAIN INCORPORATED

(Exact Name of Registrant as Specified in Its Charter)

Delaware

(State or Other Jurisdiction of Incorporation)

85 New Hampshire Avenue, Suite 150, Portsmouth, New Hampshire

(Address of Principal Executive Offices)

03801

(Zip Code)

(617) 535-4766

(Registrant’s Telephone Number, Including Area Code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities Registered Pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 5.07. Submission of Matters to a Vote of Security Holders.

The Annual Meeting of Stockholders of Iron Mountain Incorporated (the "Company") was held on May 7, 2026 (the "Annual Meeting"). At the Annual Meeting, the Company’s stockholders elected eleven directors, each for a one-year term of office to serve until the Company’s 2027 Annual Meeting of Stockholders, or until their successors are elected and qualified. The nominated directors received the following votes:

At the Annual Meeting, the Company’s stockholders approved a non-binding advisory resolution on the compensation paid to the Company’s named executive officers as disclosed pursuant to Item 402 of Regulation S-K in the Proxy Statement. This proposal received the following votes:

At the Annual Meeting, the Company’s stockholders ratified the appointment of Deloitte & Touche LLP as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2026. This proposal received the following votes:

The results reported above are final voting results.

Item 8.01. Other Events.

Committee Appointments

On May 7, 2026, upon recommendation from the Company’s Nominating and Governance Committee, the Board of Directors approved the appointment of the following members of the Company’s Audit, Compensation and Nominating and Governance Committees, effective at the conclusion of the Annual Meeting on May 7, 2026, and subject to their re-election at the Annual Meeting:

The Company also has a Finance Committee and a Risk and Safety Committee, neither of which are required by the rules of the New York Stock Exchange. On May 7, 2026, the Board of Directors, upon recommendation from the Nominating and Governance Committee, approved the appointment of the following members to these committees, effective at the conclusion of the Annual Meeting on May 7, 2026, and subject to their re-election at the Annual Meeting:

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits

101 Cover Page Interactive Data File - the cover page XBRL tags are embedded within the Inline XBRL document.

104 The cover page from this Current Report on Form 8-K, formatted as Inline XBRL.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date: May 12, 2026