X0306 4 2018-03-31 0 0000944480 GSE SYSTEMS INC GVP 0001665849 Pugh Daniel Warren C/O GSE SYSTEMS, INC. 1332 LONDONTOWN BLVD SYKESVILLE MD 21784 0 1 0 0 SVP, General Counsel & RMO Common Stock 2018-03-31 4 F 0 1513 3.25 D 57281 D Shares withheld by the Issuer for payment of applicable taxes owned due to the vesting of the 3,959 restricted share units pursuant to two restricted share unit agreements between the Reporting Person and the issuer. /s/ Daniel Warren Pugh 2018-04-02