X0306 4 2021-11-16 0 0000944480 GSE SYSTEMS INC GVP 0001649892 Loudermilk Kyle Justin 6940 COLUMBIA GATEWAY DRIVE SUITE 470 COLUMBIA MD 21046 1 1 0 0 Chief Executive Officer & Pres Common Stock 2021-11-16 4 S 0 25524 1.5500 D 809804 D Common Stock 2021-11-16 4 S 0 3100 1.5700 D 806704 D Common Stock 2021-11-16 4 S 0 5000 1.5800 D 801704 D Common Stock 2021-11-16 4 S 0 4603 1.5900 D 797101 D Common Stock 2021-11-16 4 S 0 8588 1.600 D 788513 D Common Stock 2021-11-16 4 S 0 200 1.6050 D 788313 D Common Stock 2021-11-16 4 S 0 1124 1.6100 D 787189 D Common Stock 2021-11-16 4 S 0 1861 1.6150 D 785328 D Common Stock 2021-11-17 4 S 0 1800 1.500 D 783528 D Common Stock 2021-11-17 4 S 0 1700 1.5100 D 781828 D Common Stock 2021-11-17 4 S 0 3259 1.5200 D 778569 D Common Stock 2021-11-17 4 S 0 600 1.5300 D 777969 D Common Stock 2021-11-17 4 S 0 700 1.5500 D 777269 D Common Stock 2021-11-17 4 S 0 2225 1.5600 D 775044 D Common Stock 2021-11-17 4 S 0 1220 1.5700 D 773824 D Common Stock 2021-11-17 4 S 0 300 1.5800 D 773524 D Common Stock 2021-11-17 4 S 0 4558 1.6200 D 768966 D Common Stock 2021-11-17 4 S 0 588 1.6250 D 768378 D Common Stock 2021-11-17 4 S 0 11 1.6300 D 768367 D Common Stock 2021-11-17 4 S 0 300 1.6550 D 768067 D Common Stock 2021-11-17 4 S 0 400 1.6600 D 767667 D Common Stock 2021-11-17 4 S 0 400 1.6900 D 767267 D The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan adopted by the reporting person. /s/ Kyle Justin Loudermilk 2021-11-18