Material Agreement Form 8 K

Effective June 27, 2024, ONE Gas, Inc. (the "Company") entered into a lender joinder and commitment increase agreement (the "Increase Agreement") related to its $1.2 billion second amended and restated revolving credit agreement, dated as of March 16, 2021, as amended (the "Credit Agreement"), with Bank of America, N.A., as administrative agent, swing line lender, and letter of credit issuer, and the other lenders and letter of credit issuers party thereto from time to time. The Increase Agreement (i) increases the aggregate commitments available under the Credit Agreement from $1,200,000,000 to $1,275,000,000 and (ii) joins Regions Bank as a lender under the Credit Agreement. All other terms and conditions of the Credit Agreement remain in full force and effect.

Some of the lenders under the Credit Agreement and their respective affiliates have, from time to time, performed, and may in the future perform, various financial advisory, commercial and investment banking services for the Company, for which they received or will receive customary fees and expenses. Certain affiliates of the lenders under the Credit Agreement were underwriters of the Company's prior underwritten note and equity issuances and may serve as underwriters in any future note and/or equity issuances. In addition, certain of the lenders under the Credit Agreement and their respective affiliates act as dealers in connection with the Company's commercial paper program, and also as managers, forward purchasers and/or forward sellers, including under the Company's at-the-marketequity program.

The foregoing description of the Increase Agreement is not complete and is in all respects subject to the actual provisions of the Increase Agreement, a copy of which has been filed as Exhibit 10.1 to this Current Report on Form 8-Kand which is incorporated by reference herein.