X0508 4 2026-02-25 0 0001501585 HUNTINGTON INGALLS INDUSTRIES, INC. HII 0002049633 Blanchette Brian D. 4101 WASHINGTON AVENUE NEWPORT NEWS VA 23607 0 1 0 0 Ex VP and President, Ingalls 0 Common Stock 2026-02-25 4 A 0 1445 435.58 A 3161.681 D Common Stock 2026-02-25 4 F 0 626.409 435.58 D 2535.272 D Common Stock 1408.25 I By 401(k) Plan Restricted Stock Rights 2026-02-25 4 A 0 1033 0 A Restricted Stock Rights 1033 3041.474 D SEP SEP Unit 876.5 3785.1378 D Shares issued upon settlement of restricted performance stock rights ("RPSRs") for the performance period that ended on 12/31/2025. Shares withheld by issuer for payment of withholding taxes on RPSRs. Each Restricted Stock Right ("RSR") represents a contingent right to receive an equivalent number of shares of Company common stock, or, at the discretion of the Company's Compensation Committee, cash or a combination of cash and Company common stock. The RSRs were granted under the 2022 Long-Term Incentive Stock Plan ("LTISP") on 2/25/26 and vest ratably in three equal installments upon each of the first, second, and third anniversaries of the grant date. The reporting person's interest in the HII Stock Fund of the Huntington Ingalls Industries, Inc. Savings Excess Plan (the "Plan") is held in the form of units of interest. The Plan's administrator calculates the number of shares of issuer common stock represented by units in the HII Stock Fund. /s/ Tiffany M. King, Attorney-in-Fact 2026-02-27