X0306 4 2016-04-06 0 0001084991 NATURAL GAS SERVICES GROUP INC NGS 0001340731 Hazlett James R 508 WEST WALL STREET, SUITE 550 MIDLAND TX 79701 0 1 0 0 Vice President-Technical Svcs. Common Stock 2016-04-06 4 A 0 20000 20.39 D 74856 D Employee Stock Option (right to buy) 17.51 2009-09-10 2018-09-10 Common Stock 5000 5000 D Employee Stock Option (right to buy) 17.74 2010-12-09 2019-12-08 Common Stock 10000 10000 D Employee Stock Option (right to buy) 17.81 2012-01-25 2021-01-24 Common Stock 10000 10000 D The acquisition of the 20,000 shares of common stock reflects an award of restricted stock on April 6, 2016, pursuant to the Company's 2009 Restricted Stock/Unit Plan. Fifty percent (50%) of the shares underlying the award vest upon the first anniversary of the grant date and the remaining 50% of the shares vest on the second anniversary, subject to the participant's continued employment with the Company and subject to accelerated vesting upon the death, disability or retirement of the participant, or upon a change in control of the Company. /s/ James R. Hazlett 2016-04-08