X0306 4 2016-04-06 0 0001084991 NATURAL GAS SERVICES GROUP INC NGS 0001196423 CURTIS CHARLES G 1 PENROSE LANE COLORADO SPRINGS CO 80906 1 0 0 0 Common Stock 2016-04-06 4 A 0 5884 20.39 A 72521 D Nonqualified Stock Option (right to buy) 13.90 2007-01-01 2017-01-01 Common Stock 2500 2500 D Nonqualified Stock Option (right to buy) 19.61 2007-12-31 2017-12-31 Common Stock 2500 2500 D Nonqualified Stock Option (right to buy) 20.48 2008-03-31 2018-03-18 Common Stock 2500 2500 D Nonqualified Stock Option (right to buy) 16.74 2010-03-31 2020-03-22 Common Stock 5000 5000 D The acquisition of the 5,884 shares of common stock reflects an award of restricted stock on April 6, 2016, pursuant to the Company's 2009 Restricted Stock/Unit Plan and Independent Director Compensation Policy. The award vests in installments of 1,471 shares beginning on March 31, 2017, with additional 1,471 share installments vesting on June 30, September 30 and December 31, 2017, although the award is also subject to accelerated vesting upon the death, disability or retirement of the recipient, or upon a change in control of the Company. /s/ Charles G. Curtis 2016-04-08