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Significant Accounting Policies (Policies) | 3 Months Ended
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Mar. 31, 2025
Accounting Policies [Abstract] |
Organization | ## Organization Martin Marietta Materials, Inc. (the Company or Martin Marietta) is a natural resource-based building materials company. As of March 31, 2025, the Company supplies aggregates (crushed stone, sand and gravel) through its network of approximately 390 quarries, mines and distribution yards in 28 states, Canada and The Bahamas. Martin Marietta also provides cement and downstream products and services, namely, ready mixed concrete, asphalt and paving, in vertically-integrated structured markets where the Company also has a leading aggregates position. The Company’s heavy-side building materials are used in infrastructure, nonresidential and residential construction projects. Aggregates are also used in agricultural, utility and environmental applications and as railroad ballast. The aggregates, cement and ready mixed concrete, asphalt and paving product lines are reported collectively as the Building Materials business. The Company’s Building Materials business includes two reportable segments: East Group and West Group.
BUILDING MATERIALS BUSINESS
Reportable Segments |  | East Group |  | West Group
Operating Locations |  | Alabama, Florida, Georgia, Indiana, Iowa, Kansas, Kentucky, Maryland, Minnesota, Missouri, Nebraska, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Virginia, West Virginia, Nova Scotia and The Bahamas |  | Arizona, Arkansas, California, Colorado, Louisiana, Oklahoma, Texas, Utah, Washington and Wyoming
Product Lines |  | Aggregates and Asphalt |  | Aggregates, Cement and Ready Mixed Concrete, Asphalt and Paving
The Company’s Magnesia Specialties business, which represents a separate reportable segment, has manufacturing facilities in Manistee, Michigan, and Woodville, Ohio. The Magnesia Specialties business produces magnesia-based chemicals products used in industrial, agricultural and environmental applications, and dolomitic lime sold primarily to customers for steel production and soil stabilization.
Basis of Presentation and Use of Estimates | ## Basis of Presentation and Use of Estimates The accompanying unaudited consolidated financial statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States (U.S. GAAP) for interim financial information and with the instructions to the Quarterly Report on Form 10-Q and in Article 10 of Regulation S-X. The Company has continued to follow the accounting policies set forth in the audited consolidated financial statements and related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024. In the opinion of management, the interim consolidated financial information provided herein reflects all adjustments, consisting of normal recurring accruals, necessary for a fair statement of the results of operations, financial position and cash flows for the interim periods. The consolidated results of operations for the three months ended March 31, 2025 are not necessarily indicative of the results expected for other interim periods or the full year. The consolidated balance sheet at December 31, 2024 has been derived from the audited consolidated financial statements at that date but does not include all of the information and notes required by U.S. GAAP for complete financial statements. These consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024. The preparation of the Company’s consolidated financial statements requires management to make certain estimates and assumptions about future events. As future events and their effects cannot be fully determined with precision, actual results could differ significantly from estimates. Changes in estimates are reflected in the consolidated financial statements in the period in which the change in estimate occurs.
Consolidated Comprehensive Earnings and Accumulated Other Comprehensive Loss | ## Consolidated Comprehensive Earnings and Accumulated Other Comprehensive Loss Consolidated comprehensive earnings consist of consolidated net earnings, adjustments for the funded status of pension and postretirement benefit plans and foreign currency translation adjustments, and are presented in the Company’s consolidated statements of earnings and comprehensive earnings. Consolidated comprehensive earnings attributable to Martin Marietta are as follows:
|  | Three Months Ended |
|  | March 31, |
|  | 2025 |  |  | 2024 |
|  | (Dollars in Millions) |
Net earnings attributable to Martin Marietta |  | $ | 116 |  |  | $ | 1,045 |
Other comprehensive earnings, net of tax |  |  | 1 |  |  |  | — |
Consolidated comprehensive earnings attributable to Martin Marietta |  | $ | 117 |  |  | $ | 1,045 |
Accumulated other comprehensive loss consists of unrecognized gains and losses related to the funded status of the pension and postretirement benefit plans and foreign currency translation adjustments and is presented on the Company’s consolidated balance sheets. The components of the changes in accumulated other comprehensive loss, net of tax, are as follows:
|  | (Dollars in Millions) |
|  | Pension and Postretirement Benefit Plans |  |  | Foreign Currency |  |  | Accumulated Other Comprehensive Loss |
|  | Three Months Ended March 31, 2025 |
Balance at beginning of period |  | $ | (9 | ) |  | $ | (4 | ) |  | $ | (13 | )
Amounts reclassified from accumulated other comprehensive loss, net of tax |  |  | 1 |  |  |  | — |  |  |  | 1 |
Other comprehensive earnings, net of tax |  |  | 1 |  |  |  | — |  |  |  | 1 |
Balance at end of period |  | $ | (8 | ) |  | $ | (4 | ) |  | $ | (12 | )
|  | Three Months Ended March 31, 2024 |
Balance at beginning of period |  | $ | (48 | ) |  | $ | (1 | ) |  | $ | (49 | )
Other comprehensive loss before reclassifications, net of tax |  |  | — |  |  |  | (1 | ) |  |  | (1 | )
Amounts reclassified from accumulated other comprehensive loss, net of tax |  |  | 1 |  |  |  | — |  |  |  | 1 |
Other comprehensive earnings (loss), net of tax |  |  | 1 |  |  |  | (1 | ) |  |  | — |
Balance at end of period |  | $ | (47 | ) |  | $ | (2 | ) |  | $ | (49 | )
Changes in net noncurrent deferred tax assets related to accumulated other comprehensive loss are as follows:
|  | Pension and Postretirement Benefit Plans |
|  | Three Months Ended |
|  | March 31, |
|  | 2025 |  |  | 2024 |
|  | (Dollars in Millions) |
Balance at beginning of period |  | $ | 41 |  |  | $ | 54 |
Tax effect of other comprehensive earnings |  |  | (1 | ) |  |  | (1 | )
Balance at end of period |  | $ | 40 |  |  | $ | 53 |
Reclassifications out of accumulated other comprehensive loss are as follows:
|  | Three Months Ended |  |  | Affected line items in the consolidated
|  | March 31, |  |  | statements of earnings
|  | 2025 |  |  | 2024 |  |  | and comprehensive earnings
|  | (Dollars in Millions) |
Pension and postretirement benefit plans |  |  |  |  |  |  |  |
Amortization of prior service cost |  | $ | 2 |  |  | $ | 2 |  |  | Other nonoperating income, net
Tax effect |  |  | (1 | ) |  |  | (1 | ) |  | Income tax expense
Total |  | $ | 1 |  |  | $ | 1 |  |  |
Earnings per Common Share | ## Earnings per Common Share The numerator for basic and diluted earnings per common share is net earnings attributable to Martin Marietta. The denominator for basic earnings per common share is the weighted-average number of common shares outstanding during the period. Diluted earnings per common share is computed assuming that the weighted-average number of common shares is increased by the conversion, using the treasury stock method, of awards to be issued to employees and nonemployee members of the Company’s Board of Directors under certain stock-based compensation arrangements if the conversion is dilutive. The following table reconciles the denominator for basic and diluted earnings per common share:
|  | Three Months Ended |
|  | March 31, |
|  | 2025 |  |  | 2024 |
|  | (In Millions) |
Basic weighted-average common shares outstanding |  |  | 60.9 |  |  |  | 61.8 |
Effect of dilutive employee and director awards |  |  | 0.1 |  |  |  | 0.2 |
Diluted weighted-average common shares outstanding |  |  | 61.0 |  |  |  | 62.0 |
New Accounting Pronouncements | ## New Accounting Pronouncements In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which focuses on the rate reconciliation and income taxes paid. ASU 2023-09 requires public entities to disclose, on an annual basis, a tabular tax rate reconciliation using both percentages and currency amounts, broken out into specified categories. Certain reconciling items are further broken out by nature and jurisdiction to the extent those items exceed a specified threshold. Additionally, all entities are required to disclose income taxes paid, net of refunds received, disaggregated by federal, state/local, and foreign taxes and by individual jurisdiction if the amount is at least 5% of total income tax payments, net of refunds received. The ASU also requires additional qualitative disclosures. ASU 2023-09 is effective prospectively for annual periods beginning after December 15, 2024, and early adoption and retrospective application are permitted. The ASU will impact the Company's income tax disclosures beginning with the financial statements included in the 2025 Annual Report on Form 10-K, but will have no impact on its results of operations, cash flows or financial condition. In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses (DISE), which requires public entities to disaggregate any relevant expense caption presented on the face of the income statement within continuing operations into the following required natural expense categories, as applicable: (1) purchases of inventory, (2) employee compensation, (3) depreciation, (4) intangible asset amortization, and (5) depreciation, depletion and amortization recognized as part of oil- and gas-producing activities or other depletion expenses. These disclosures must be made in a tabular format in the footnotes to the financial statements. The new standard does not change the requirements for the presentation of expenses on the face of the statement of earnings. The ASU is effective prospectively for annual reporting periods beginning after December 15, 2026 and interim reporting periods beginning after December 15, 2027, and early adoption and retrospective application are permitted. The ASU will impact the Company's expense disclosures beginning with the financial statements included in the 2027 Annual Report on Form 10-K, but will have no impact on its results of operations, cash flows or financial condition.
Reclassifications | ## Reclassifications Certain reclassifications have been made in the Company's financial statements of the prior year to conform to the current-year presentation. The reclassifications had no impact on the Company’s previously reported results of operations, financial condition or cash flows.

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