X0306 4 2022-03-01 0 0001501585 HUNTINGTON INGALLS INDUSTRIES, INC. HII 0001846302 Stiehle Thomas E. C/O HUNTINGTON INGALLS INDUSTRIES, INC. 4101 WASHINGTON AVE NEWPORT NEWS VA 23607 0 1 0 0 Ex. VP and CFO Common Stock 2022-03-01 4 A 0 1867 204.15 A 14628.452 D Common Stock 2022-03-01 4 F 0 856 204.15 D 13772.452 D The Huntington Ingalls Industries, Inc. Compensation Committee determined that all performance goals had been met for these restricted stock units, and they were issued on March 1, 2022. Shares withheld by the issuer for the payment of withholding taxes on restricted stock that vested on March 1, 2022. /s/ Kathy S. Owen, Attorney-in-Fact for Thomas E. Stiehle 2022-03-03