X0306 4 2016-01-30 0 0001431372 Gastar Exploration Inc. GST 0001348370 Gerlich Michael A 1331 LAMAR, SUITE 650 HOUSTON TX 77010 0 1 0 0 Senior VP & CFO Common Stock 2016-01-30 4 A 0 191176 0.00 A 1115041 D Common Stock 2016-01-30 4 F 0 40887 1.19 D 1074154 D Common Stock 2016-01-30 4 M 0 160200 0.00 A 1234354 D Common Stock 2016-01-30 4 F 0 45646 1.19 D 1188708 D 2013 Performance Based Units 0.00 2016-01-30 4 M 0 80100 0.00 D 2016-01-30 Common Stock 80100 0 D 2014 Performance Based Units 0.00 2016-01-30 4 J 0 17529 0.00 D 2017-01-30 Common Stock 17529 17528 D 2015 Performance Based Units 0.00 2018-01-30 Common Stock 135417 135417 D 2016 Performance Based Units 0.00 2016-01-30 4 A 0 191176 0.00 A 2019-01-30 Common Stock 191176 191176 D The reported shares were acquired pursuant to a restricted share grant and will vest in three equal annual installments beginning on January 30, 2017. Includes 298,985 shares acquired on various dates pursuant to previously reported restricted share grants that will vest subject to previously disclosed vesting schedules. Shares forfeited to meet tax obligation of restricted share vesting. Common stock acquired as a result of the 2013 performance based unit award vesting at 200% of the target award based on Gastar's share price appreciation over the performance period. Shares forfeited to meet tax obligation of performance based unit vesting. These performance based units ("PBUs") vest ratably over a three-year performance period as previously reported. These PBUs vested and forfeited as a result of the 2014 PBU award settling at 0% of the target award based on Gastar's share price depreciation over the performance period. These PBUs vest in their entirety at the end of a three-year performance period as previously reported. These PBUs vest in their entirety at the end of the three-year performance period with settlement in common stock between 0% and 200% (**subject to limitations discussed in Footnote 10 below) of the target award based on Gastar's share price appreciation over a three-year performance period relative to a peer index. Share price appreciation is measured generally as the change in market value of common stock during the performance period. The PBUs have no voting rights but provide for dividend equivalents to be paid upon vesting. The number of PBUs reported (191,176) represents the target award. As such, the number of shares that may be issued upon vesting ranges from 0 shares to 382,352 shares. **As discussed in Footnote 9 above, at the end of the performance period, the participant may earn up to 200% of the target award, subject to a maximum award limitation of one million (1,000,000) shares that may be issued to any individual in a calendar year under the Gastar Exploration Inc. Long-Term Incentive Plan. /s/ Michael A. Gerlich 2016-02-02