X0306 4 2021-03-18 0 0001084991 NATURAL GAS SERVICES GROUP INC ngs 0001173236 CHISHOLM JOHN 404 VETERANS AIRPARK LANE SUITE 300 MIDLAND TX 79705 1 0 0 0 Common Stock 2021-03-18 4 A 0 5612 8.91 A 26792 D The acquisition reflects an award of Restricted Stock pursuant to the Company's 2019 Equity Incentive Plan. The award vests on the first anniversary of the grant date, subject to accelerated vesting under certain circumstances. John M. Chisholm 2021-03-22