X0306 4 2018-02-21 0 0001587732 ONE Gas, Inc. OGS 0001595607 McCormick Joseph L 15 E. 5TH STREET TULSA OK 74103 0 1 0 0 See Remarks Common stock, par value $0.01 2018-02-19 4 M 0 12488 68.17 A 54294 D Common stock, par value $0.01 2018-02-19 4 F 0 5532 68.17 D 48762 D Common stock, par value $0.01 2018-02-17 4 M 0 1561 68.17 A 50323 D Common stock, par value $0.01 2018-02-17 4 F 0 758 68.17 D 49565 D Common stock, par value $0.01 2887 I by 401(k) Plan Performance Units 2015 2018-02-19 4 M 0 5800 68.17 D Common stock, par value $0.01 5800 0 D Restricted Units 2015 2018-02-17 4 M 0 1450 68.17 D Common stock, par value $0.01 1450 0 D Performance Units 2018 2018-02-19 4 A 0 4401 68.17 A Common stock, par value $0.01 4401 4401 D Restricted Units 2018 2018-02-19 4 A 0 1100 68.17 A Common stock, par value $0.01 1100 1100 D Performance units awarded under Issuer's Equity Compensation Plan. The award vested on February 17, 2018, and was certified by the Executive Compensation Committee of the Board of Directors on February 19, 2018. The award vested in an amount equal to 200% of the performance units awarded based upon Issuer's total shareholder return compared to total shareholder return of a selected peer group plus accrued dividends of 888 shares. The award was payable one share of Issuer's common stock for each vested performance unit and accrued dividends. Restricted units awarded under Issuer's Equity Compensation Plan. The award vested on February 17, 2018. The award was payable one share of Issuer's common stock for each vested restricted unit and accrued dividends of 111 shares. Performance units awarded under the Issuer's Equity Compensation Plan. The award will vest on February 13, 2021, for a percentage (0% to 200%) of the performance units awarded based upon the Issuer's total shareholder return compared to total stockholder return of a selected peer group. During the 3-year vesting period, the award will be credited with dividend equivalents that will be paid out in shares of common stock at the time the underlying units vest and shares are issued. The award and credited dividend equivalents will be payable one share of the Issuer's common stock for each vested performance unit and dividend equivalent. Restricted units awarded under the Issuer's Equity Compensation Plan. The award vests on February 13, 2021. During the 3-year vesting period, the award will be credited with dividend equivalents that will be paid out in shares of common stock at the time the underlying units vest and are issued. The award and credited dividend equivalents will be payable one share of the Issuer's common stock for each vested restricted unit and dividend equivalent. Senior Vice President, General Counsel and Assistant Secretary /s/ Brian K. Shore, Attorney-in-Fact for Joseph L. McCormick 2018-02-21