OGS · ONE Gas, Inc.

In conjunction with Mr. McCormick's retirement on December 9, 2025, distribution of restricted units awarded under Issuer's Amended and Restated Equity Compensation Plan (2018). The award vested on a pro-rata basis six months following the date of retirement in accordance with the terms of the grant agreement. The award and credited dividend equivalents are payable one share of the Issuer's common stock for each vested restricted unit and dividend equivalent.

In conjunction with Mr. McCormick's retirement on December 9, 2025, distribution of restricted units awarded under Issuer's Amended and Restated Equity Compensation Plan (2018). The award vested on a pro-rata basis six months following the date of retirement in accordance with the terms of the grant agreement. The award and credited dividend equivalents are payable one share of the Issuer's common stock for each vested restricted unit and dividend equivalent.

In conjunction with Mr. McCormick's retirement on December 9, 2025, distribution of restricted units awarded under Issuer's Amended and Restated Equity Compensation Plan (2018). The award vested on a pro-rata basis six months following the date of retirement in accordance with the terms of the grant agreement. The award and credited dividend equivalents are payable one share of the Issuer's common stock for each vested restricted unit and dividend equivalent.

In conjunction with Mr. McCormick's retirement on December 9, 2025, distribution of restricted units awarded under Issuer's Amended and Restated Equity Compensation Plan (2018). The award vested on a pro-rata basis six months following the date of retirement in accordance with the terms of the grant agreement. The award and credited dividend equivalents are payable one share of the Issuer's common stock for each vested restricted unit and dividend equivalent.

In conjunction with Mr. McCormick's retirement on December 9, 2025, distribution of restricted units awarded under Issuer's Amended and Restated Equity Compensation Plan (2018). The award vested on a pro-rata basis six months following the date of retirement in accordance with the terms of the grant agreement. The award and credited dividend equivalents are payable one share of the Issuer's common stock for each vested restricted unit and dividend equivalent.

In conjunction with Mr. McCormick's retirement on December 9, 2025, distribution of restricted units awarded under Issuer's Amended and Restated Equity Compensation Plan (2018). The award vested on a pro-rata basis six months following the date of retirement in accordance with the terms of the grant agreement. The award and credited dividend equivalents are payable one share of the Issuer's common stock for each vested restricted unit and dividend equivalent.

In conjunction with Mr. McCormick's retirement on December 9, 2025, distribution of restricted units awarded under Issuer's Amended and Restated Equity Compensation Plan (2018). The award vested on a pro-rata basis six months following the date of retirement in accordance with the terms of the grant agreement. The award and credited dividend equivalents are payable one share of the Issuer's common stock for each vested restricted unit and dividend equivalent.

In conjunction with Mr. McCormick's retirement on December 9, 2025, distribution of restricted units awarded under Issuer's Amended and Restated Equity Compensation Plan (2018). The award vested on a pro-rata basis six months following the date of retirement in accordance with the terms of the grant agreement. The award and credited dividend equivalents are payable one share of the Issuer's common stock for each vested restricted unit and dividend equivalent.

In conjunction with Mr. McCormick's retirement on December 9, 2025, distribution of restricted units awarded under Issuer's Amended and Restated Equity Compensation Plan (2018). The award vested on a pro-rata basis six months following the date of retirement in accordance with the terms of the grant agreement. The award and credited dividend equivalents are payable one share of the Issuer's common stock for each vested restricted unit and dividend equivalent.

Represents settlement of deferred stock units credited under the ONE Gas Deferred Compensation Plan for Non-Employee Directors (the "Plan"), payable in shares of common stock and convertible on a 1-for-1 ratio pursuant to the ONE Gas, Inc. Amended and Restated Equity Compensation Plan (2018) following the reporting person's retirement on May 21, 2026. 19,976 phantom stock units, including dividend-equivalent units credited through the June 2, 2026 dividend payment date, were settled in shares of common stock on June 3, 2026.

Pursuant to the ONEOK distribution the reporting person received one share of ONE Gas common stock for every four shares of ONEOK common stock on January 21, 2014. Represents settlement of deferred stock units credited under the ONE Gas Deferred Compensation Plan for Non-Employee Directors (the "Plan"), payable in shares of common stock and convertible on a 1-for-1 ratio pursuant to the ONE Gas, Inc. Amended and Restated Equity Compensation Plan (2018) following the reporting person's retirement from ONEOK, Inc. on May 20, 2026. 5,638 phantom stock units, including dividend-equivalent units credited through the June 2, 2026, dividend payment date, were settled in shares of common stock on June 3, 2026.

The reporting person continues to hold phantom stock units subject to prior deferred distribution elections, which remain payable pursuant to the Plan.

Pursuant to the ONEOK distribution the reporting person received one share of ONE Gas common stock for every four shares of ONEOK common stock on January 21, 2014. Represents settlement of deferred stock units credited under the ONE Gas Deferred Compensation Plan for Non-Employee Directors (the "Plan"), payable in shares of common stock and convertible on a 1-for-1 ratio pursuant to the ONE Gas, Inc. Amended and Restated Equity Compensation Plan (2018) following the reporting person's retirement from ONEOK, Inc. on May 20, 2026. 5,638 phantom stock units, including dividend-equivalent units credited through the June 2, 2026, dividend payment date, were settled in shares of common stock on June 3, 2026.

Represents settlement of deferred stock units credited under the ONE Gas Deferred Compensation Plan for Non-Employee Directors (the "Plan"), payable in shares of common stock and convertible on a 1-for-1 ratio pursuant to the ONE Gas, Inc. Amended and Restated Equity Compensation Plan (2018) following the reporting person's retirement on May 21, 2026. 19,976 phantom stock units, including dividend-equivalent units credited through the June 2, 2026 dividend payment date, were settled in shares of common stock on June 3, 2026.

The reporting person continues to hold phantom stock units subject to prior deferred distribution elections, which remain payable in future installments pursuant to the Plan.

Annual stock retainer shares are issued under ONE Gas' Amended and Restated Equity Compensation Plan (2018).

Annual stock retainer shares are issued under the Issuer's Amended and Restated Equity Compensation Plan (2018).

Shares of deferred stock are convertible into ONE Gas' common stock on a 1-for-1 ratio.

Annual stock retainer elected to be deferred under ONE Gas' Deferred Compensation Plan for Non-Employee Directors.

Deferred stock is accrued under ONE Gas' Deferred Compensation Plan for Non-Employee Directors (the "Plan") and is settled in shares of ONE Gas common stock at the distribution date described in the Plan.

Shares of deferred stock are convertible into ONE Gas' common stock on a 1-for-1 ratio.

Annual cash and/or stock retainer elected to be deferred under ONE Gas' Deferred Compensation Plan for Non-Employee Directors.

Deferred stock is accrued under ONE Gas' Deferred Compensation Plan for Non-Employee Directors (the "Plan") and is settled in shares of ONE Gas common stock at the distribution date described in the Plan.

Annual stock retainer shares are issued under the Issuer's Amended and Restated Equity Compensation Plan (2018).

Shares of deferred stock are convertible into ONE Gas' common stock on a 1-for-1 ratio.

Annual cash and/or stock retainer elected to be deferred under ONE Gas' Deferred Compensation Plan for Non-Employee Directors.

Deferred stock is accrued under ONE Gas' Deferred Compensation Plan for Non-Employee Directors (the "Plan") and is settled in shares of ONE Gas common stock at the distribution date described in the Plan.

Annual stock retainer shares are issued under the Issuer's Equity Compensation Plan.

Shares of deferred stock are convertible into ONE Gas' common stock on a 1-for-1 ratio.

Annual stock retainer elected to be deferred under ONE Gas' Deferred Compensation Plan for Non-Employee Directors.

Deferred stock is accrued under ONE Gas' Deferred Compensation Plan for Non-Employee Directors (the "Plan") and is settled in shares of ONE Gas common stock at the distribution date described in the Plan.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award will vest on February 17, 2029, 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 over the performance period from January 1, 2026, through December 31, 2029, in accordance with the terms of the Performance Unit Award Agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award, including dividend equivalents, vested on February 14, 2026, in an amount equal to 76% of the performance units awarded based upon Issuer's total shareholder return compared to the total shareholder return of a selected peer group, was certified by the Executive Compensation Committee of the Board of Directors on February 16, 2026, and issued pursuant to the terms of the grant agreement.

Restricted units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award vests on February 17, 2029, in accordance with the terms of the Restricted Unit Award Agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award, including dividend equivalents, vested on a prorated basis upon the reporting person's December 9, 2025, retirement pursuant to the terms of the award agreement. The award vested on February 14, 2026, in an amount equal to 76% of the performance units awarded based upon Issuer's total shareholder return compared to the total shareholder return of a selected peer group, was certified by the Executive Compensation Committee of the Board of Directors on February 16, 2026, and issued pursuant to the terms of the grant agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award, including dividend equivalents, vested on a prorated basis upon the reporting person's December 9, 2025, retirement pursuant to the terms of the award agreement. The award vested on February 14, 2026, in an amount equal to 76% of the performance units awarded based upon Issuer's total shareholder return compared to the total shareholder return of a selected peer group, was certified by the Executive Compensation Committee of the Board of Directors on February 16, 2026, and issued pursuant to the terms of the grant agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award will vest on February 17, 2029, 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 over the performance period from January 1, 2026, through December 31, 2029, in accordance with the terms of the Performance Unit Award Agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award will vest on February 17, 2029, 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 over the performance period from January 1, 2026, through December 31, 2029, in accordance with the terms of the Performance Unit Award Agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award, including dividend equivalents, vested on February 14, 2026, in an amount equal to 76% of the performance units awarded based upon Issuer's total shareholder return compared to the total shareholder return of a selected peer group, was certified by the Executive Compensation Committee of the Board of Directors on February 16, 2026, and issued pursuant to the terms of the grant agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award, including dividend equivalents, vested on February 14, 2026, in an amount equal to 76% of the performance units awarded based upon Issuer's total shareholder return compared to the total shareholder return of a selected peer group, was certified by the Executive Compensation Committee of the Board of Directors on February 16, 2026, and issued pursuant to the terms of the grant agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award, including dividend equivalents, vested on February 14, 2026, in an amount equal to 76% of the performance units awarded based upon Issuer's total shareholder return compared to the total shareholder return of a selected peer group, was certified by the Executive Compensation Committee of the Board of Directors on February 16, 2026, and issued pursuant to the terms of the grant agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award, including dividend equivalents, vested on February 14, 2026, in an amount equal to 76% of the performance units awarded based upon Issuer's total shareholder return compared to the total shareholder return of a selected peer group, was certified by the Executive Compensation Committee of the Board of Directors on February 16, 2026, and issued pursuant to the terms of the grant agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award will vest on February 17, 2029, 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 over the performance period from January 1, 2026, through December 31, 2029, in accordance with the terms of the Performance Unit Award Agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award, including dividend equivalents, vested on February 14, 2026, in an amount equal to 76% of the performance units awarded based upon Issuer's total shareholder return compared to the total shareholder return of a selected peer group, was certified by the Executive Compensation Committee of the Board of Directors on February 16, 2026, and issued pursuant to the terms of the grant agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award, including dividend equivalents, vested on February 14, 2026, in an amount equal to 76% of the performance units awarded based upon Issuer's total shareholder return compared to the total shareholder return of a selected peer group, was certified by the Executive Compensation Committee of the Board of Directors on February 16, 2026, and issued pursuant to the terms of the grant agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award, including dividend equivalents, vested on February 14, 2026, in an amount equal to 76% of the performance units awarded based upon Issuer's total shareholder return compared to the total shareholder return of a selected peer group, was certified by the Executive Compensation Committee of the Board of Directors on February 16, 2026, and issued pursuant to the terms of the grant agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award, including dividend equivalents, vested on February 14, 2026, in an amount equal to 76% of the performance units awarded based upon Issuer's total shareholder return compared to the total shareholder return of a selected peer group, was certified by the Executive Compensation Committee of the Board of Directors on February 16, 2026, and issued pursuant to the terms of the grant agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award, including dividend equivalents, vested on February 14, 2026, in an amount equal to 76% of the performance units awarded based upon Issuer's total shareholder return compared to the total shareholder return of a selected peer group, was certified by the Executive Compensation Committee of the Board of Directors on February 16, 2026, and issued pursuant to the terms of the grant agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award, including dividend equivalents, vested on a prorated basis upon the reporting person's December 9, 2025, retirement pursuant to the terms of the award agreement. The award vested on February 14, 2026, in an amount equal to 76% of the performance units awarded based upon Issuer's total shareholder return compared to the total shareholder return of a selected peer group, was certified by the Executive Compensation Committee of the Board of Directors on February 16, 2026, and issued pursuant to the terms of the grant agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award will vest on February 17, 2029, 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 over the performance period from January 1, 2026, through December 31, 2029, in accordance with the terms of the Performance Unit Award Agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018) (the "ECP"). The award, including dividend equivalents, vested on February 14, 2026, in an amount equal to 76% of the performance units awarded based upon Issuer's total shareholder return compared to the total shareholder return of a selected peer group, was certified by the Executive Compensation Committee of the Board of Directors on February 16, 2026, and issued pursuant to the terms of the grant agreement. The reporting person's receipt of 1,361.820 shares of common stock was deferred resulting in the reporting person's receipt of 1,361.820 deferred stock units. The deferred stock units become payable in shares of common stock after the reporting person's termination of service, pursuant to the reporting person's distribution election.

(Continued from footnote 1) The reporting person is therefore reporting the disposition of 1,361.820 shares of common stock in exchange for an equal number of deferred stock units. The reporting person had 61.527 shares withheld and cancelled in respect of taxes in connection with the vesting of the performance units.

Restricted units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award vests on February 17, 2029, in accordance with the terms of the Restricted Unit Award Agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award, including dividend equivalents, vested on February 14, 2026, in an amount equal to 76% of the performance units awarded based upon Issuer's total shareholder return compared to the total shareholder return of a selected peer group, was certified by the Executive Compensation Committee of the Board of Directors on February 16, 2026, and issued pursuant to the terms of the grant agreement.

Restricted units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award vests on February 17, 2029, in accordance with the terms of the Restricted Unit Award Agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award will vest on February 17, 2029, 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 over the performance period from January 1, 2026, through December 31, 2029, in accordance with the terms of the Performance Unit Award Agreement.

Performance units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award will vest on February 17, 2029, 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 over the performance period from January 1, 2026, through December 31, 2029, in accordance with the terms of the Performance Unit Award Agreement.

Restricted units awarded under the Issuer's Amended and Restated Equity Compensation Plan (2018). The award vests on February 17, 2029, in accordance with the terms of the Restricted Unit Award Agreement.