HUNTINGTON INGALLS INDUSTRIES, INC.

8. INCOME TAXES

The Company's earnings are primarily domestic, and its effective income tax rates on earnings from operations for the three months ended March 31, 2026 and 2025, were 20.7% and 20.3%, respectively.

For thethree months ended March 31, 2026, the Company’s effective tax rate did not differ materially from the federal statutory corporate income tax rate of 21%.

The Company's unrecognized tax benefits increased by $3 million during the three months ended March 31, 2026. As of March 31, 2026, the estimated amounts of the Company's unrecognized tax benefits, excluding interest and penalties, were liabilities of $108 million. Assuming a sustainment of these tax positions, a reversal of $85 million of the accrued amounts would favorably affect the Company's effective federal income tax rate in future periods.

The Company recognizes interest and penalties related to unrecognized tax benefits as income tax expense. For the three months ended March 31, 2026, interest and penalties resulting from the unrecognized tax benefits noted above increased income tax expense by $2 million.

Non-current state income taxes include deferred state income taxes, which reflect the change in deferred state tax assets and liabilities and the tax expense or benefit associated with changes in state unrecognized tax benefits in the relevant period. These amounts are recorded within operating income. Current period state income tax expense is charged to contract costs and included in cost of sales and service revenues in segment operating income.

Internal Revenue Service ("IRS") Audits - The Company reached an agreement in principle with the IRS on the research and development tax credits for the 2016-2021 tax years in 2025. This resolution was submitted to the Joint Committee on Taxation for approval in March 2026. Also, in the first quarter of 2026, the IRS initiated an audit of the research and development tax credits claimed on the Company's filed returns for the 2022-2023 tax years. The Company believes that its unrecognized tax benefits are adequate and will cover the expected impact of the agreement with the IRS and any adjustments resulting from the IRS audit of the 2022-2023 research and development tax credits.