Martin Marietta Materials Inc — Current Report (Form 8-K)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 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): August 11, 2026

Martin Marietta Materials, Inc.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: 919-781-4550

Not Applicable

(Former name or former address, if changed since last report)

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:

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. ☐

In connection with the offering of $750 million aggregate principal amount of 4.850% Senior Notes due 2029 (the “2029 Notes”), $1,250 million aggregate principal amount of 5.200% Senior Notes due 2032 (the “2032 Notes”), $1,000 million aggregate principal amount of 5.400% Senior Notes due 2034 (the “2034 Notes”), $1,500 million aggregate principal amount of 5.625% Senior Notes due 2036 (the “2036 Notes”) and $1,000 million aggregate principal amount of 6.375% Senior Notes due 2056 (the “2056 Notes” and, together with the 2029 Notes, 2032 Notes, 2034 Notes and 2036 Notes, the “Notes”) on August 11, 2026, Martin Marietta Materials, Inc. (“Martin Marietta” or the “Company”) entered into an underwriting agreement (the “Underwriting Agreement”) with Goldman Sachs & Co. LLC, J.P. Morgan Securities LLC, Deutsche Bank Securities Inc. and Truist Securities, Inc., as representatives of the several underwriters named therein (the “Underwriters”) pursuant to which the Underwriters agreed to purchase the Notes from the Company. The Underwriting Agreement contains the terms and conditions of the offering and sale of the Notes, indemnification and contribution obligations and other customary terms and conditions.

The foregoing description of the Underwriting Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the Underwriting Agreement, which is attached hereto as Exhibit 1.1 and incorporated by reference herein.

In accordance with General Instruction B.2. of Form 8-K, the following information and the attached Exhibit 99.1 shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended. Martin Marietta disclaims any intention or obligation to update or revise this information.

Attached as Exhibit 99.1, and incorporated herein by reference, is a copy of Martin Marietta’s press release dated August 12, 2026, announcing the pricing of the Notes.

This current report does not constitute an offer to sell or a solicitation of an offer to buy, nor shall there be any sale of the Notes in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction.

SIGNATURE

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.