X0306 4 2022-06-30 0 0000944480 GSE SYSTEMS INC GVP 0001851025 Greene Brian GSE SYSTEMS 6940 COLUMBIA GATEWAY DRIVE, SUITE 470 COLUMBIA MD 21046-3308 0 1 0 0 VP NITC Common Stock 2022-06-30 4 F 0 2280 1.25 D 48197 D Shares withheld by the Issuer for payment of applicable taxes owed due to the vesting of 6,438 restricted share units pursuant to two restricted share unit agreements between the Reporting Person and the Issuer. /s/ Brian Greene 2022-07-01