X0407 4 2023-03-31 0000944480 GSE SYSTEMS INC GVP 0001665849 Pugh Daniel Warren C/O GSE SYSTEMS, INC. 6940 COLUMBIA GATEWAY DR STE 470 COLUMBIA MD 21046 true Chief Legal and Risk Officer false Common Stock 2023-03-31 4 F 0 2266 0.695 A 123842 D Shares withheld by the Issuer for payment of applicable taxes owed due to the vesting of 5,868 restricted share units pursuant to two restricted share unit agreements between the Reporting Person and the Issuer. /s/ Pugh Daniel Warren 2023-04-04