X0306 4 2017-12-19 0 0001084991 NATURAL GAS SERVICES GROUP INC ngs 0001385056 Lawrence G Larry C/O LEGACY RESERVES GP, LLC 303 W. WALL STREET, SUITE 1600 MIDLAND TX 79701 0 1 0 0 Chief Financial Officer Common Stock 2017-12-19 4 S 0 6000 25.23 D 39478 D Restricted Stock Units Common Stock 15000 15000 D Employee Stock Option 17.81 2012-01-25 2021-01-24 Common Stock 5000 5000 D Not Applicable. Each RSU represents the right to receive one share of the Company's Common Stock upon vesting without payment. Not Applicable. G. Larry Lawrence 2017-12-20