X0306 4 2018-03-15 0 0001084991 NATURAL GAS SERVICES GROUP INC ngs 0001340731 Hazlett James R 2208 S.C.R. 1084 1/2 MIDLAND TX 79706 0 1 0 0 VP -- Technical Services Common Stock 2018-03-15 4 A 0 16000 24.55 A 61282 D Restricted Stock Units 2018-03-15 4 A 0 4000 0 A Common Stock 4000 4000 D Restricted Stock Units Common Stock 15000 15000 D Employee Stock Option 17.74 2010-12-09 2019-12-08 Common Stock 10000 10000 D Employee Stock Option 17.81 2012-01-25 2021-01-24 Common Stock 10000 10000 D The acquisition reflects an award of Restricted Stock pursuant to the Company's 2009 Restricted Stock/Unit Plan, as amended. The award vests in one-third annual increments beginning upon the first anniversary of the grant date, subject to the reporting person's continued employment with the Company and subject to accelerated vesting upon death or disability of the reporting person, or upon certain change in control events. Not Applicable. The acquisition reflects an award of Restricted Stock Units ("RSU") pursuant to the Company's 2009 Restricted Stock/Unit Plan, as amended. Each RSU represents the right to receive one share of the Company's common stock upon vesting without payment. The award vests in one-third annual increments beginning upon the first anniversary of the grant date, subject to the reporting person's continued employment with the Company and subject to accelerated vesting upon death or disability of the reporting person, or upon certain change in control events. Not Applicable. Each Restricted Stock Unit represents a right to receive one share of Company common stock upon vesting without payment. James R. Hazlett 2018-03-19