X0306 4 2017-03-31 0 0000944480 GSE SYSTEMS INC GVP 0001660032 Meyssami Bahram C/O GSE SYSTEMS, INC. 1332 LONDONTOWN BLVD SYKESVILLE MD 21784 0 1 0 0 Chief Technology Officer Common Stock 2017-03-31 4 F 0 783 3.40 D 133525 D Shares withheld by the Issuer for payment of applicable taxes owed due to the vesting of 2,156 restricted share units pursuant to the restricted share unit agreement between the Reporting Person and the issuer. /s/ Bahram Meyssami 2017-04-04