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

Martin Marietta Materials, Inc.

(Exact Name of Registrant as Specified in Its Charter)

North Carolina

(State or Other Jurisdiction of Incorporation)

(919) 781-4550

(Registrant’s Telephone Number, Including Area Code)

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:

Item 4.01 Changes in Registrant’s Certifying Accountant.

The Audit Committee (the “Audit Committee”) of the Board of Directors of Martin Marietta Materials, Inc. (the “Company”) conducted a competitive process with multiple firms to determine the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2016. The Audit Committee invited several firms to participate in this process, including Ernst & Young LLP (“EY”), the Company’s independent registered public accounting firm for the fiscal year ended December 31, 2015 and prior fiscal years. As a result of this process, on March 14, 2016, the Audit Committee dismissed EY as its independent registered public accounting firm for the fiscal year ending December 31, 2016.

During the fiscal years ended December 31, 2015 and 2014 and in the subsequent interim period through March 14, 2016, there were no “disagreements” (as that term is described in Item 304(a)(1)(iv) of Regulation S-K and the related instructions) with EY on any matters of accounting principles or practices, financial statement disclosure, or auditing scope or procedure which, if not resolved to the satisfaction of EY, would have caused EY to make reference to the subject matter of such disagreements in their reports on the consolidated financial statements.

The audit reports of EY on the Company’s consolidated financial statements as of and for the fiscal years ended December 31, 2015 and 2014 did not contain an adverse opinion or a disclaimer of opinion, and were not qualified or modified as to uncertainty, audit scope or accounting principles.  During the fiscal years ended December 31, 2015 and 2014 and in the subsequent interim period through March 14, 2016 there were no “reportable events” as that term is described in Item 304(a)(1)(v) of Regulation S-K of the rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”).

The Company provided EY with a copy of the disclosures it is making in this Form 8-K prior to the time this Form 8-K was filed with the SEC. The Company requested EY to furnish it a letter addressed to the SEC stating whether it agrees with the above statements. A copy of that letter, dated March 18, 2016, is filed as Exhibit 16.1 to this Form 8-K.

Engagement of New Independent Registered Public Accounting Firm

On March 14, 2016, the Audit Committee approved the appointment of PricewaterhouseCoopers LLP (“PwC”) as the Company’s new independent registered public accounting firm for the year ending December 31, 2016.

During the fiscal years ended December 31, 2015 and 2014 and in the subsequent interim period through March 14, 2016, neither the Company nor anyone acting on its behalf consulted with PwC  regarding (i) the application of accounting principles to a specific transaction, either completed or proposed, or the type of audit opinion that might be rendered on the Company’s consolidated financial statements, and neither a written report nor oral advice was provided to the Company that PwC concluded was an important factor considered by the Company in reaching a decision as to any accounting, auditing, or financial reporting issue, (ii) any matter that was the subject of a disagreement as defined in Item 304(a)(1)(iv) of Regulation S-K, or (iii) any reportable event as defined in Item 304(a)(1)(v) of Regulation S-K.

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.

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