X0508 4 2023-12-31 0000944480 GSE SYSTEMS INC GVP 0001660032 Meyssami Bahram C/O GSE SYSTEMS, INC. 6940 COLUMBIA GATEWAY DR, SUITE 470 COLUMBIA MD 21784 true Chief Technology Officer false Common Stock 2023-12-31 4 F 0 225 2.01 D 23428 D Shares withheld by the Issuer for payment of applicable taxes owed due to the vesting of 671 restricted share units pursuant to two restricted share unit agreements between the Reporting Person and the Issuer. All beneficially owned securities reflect the ten-for-one reverse stock split effected on October 30, 2023. /s/ Meyssami Bahram 2024-01-03