POWER OF ATTORNEY

     KNOW ALL MEN BY THESE PRESENTS, that the undersigned hereby constitutes and
appoints Joseph L. McCormick and Brian K. Shore, the undersigned's true and
lawful attorneys-in-fact to:

(1)  Execute for and on behalf of the undersigned, in the undersigned's capacity
     as an officer of ONE Gas, Inc. (the Corporation), Forms 3, 4, and 5 in
     accordance with Section 16(a) of the Securities Exchange
     Act of 1934 and the rules thereunder;

(2)  Do and perform any and all acts for and on behalf of the undersigned which
     may be necessary or desirable to complete and execute any such Forms 3, 4,
     or 5 and timely file such form with the United
     States Securities and Exchange Commission and any stock exchange or similar
     authority;

(3)  Take any other action of any type whatsoever in connection with the
     foregoing which, in the opinion of such attorneys-in-fact, may be of
     benefit to, in the best interest of, or legally required by the
     undersigned, it being understood that the documents executed by such
     attorneys-in-fact on behalf of the undersigned pursuant to this Power of
     Attorney shall be in such form and shall contain the terms and conditions
     as such attorneys-in-fact may approve in such attorneys-in-fact's
     discretion.

     The undersigned hereby grants to each such attorneys-in-fact full power and
authority to do and perform any and every act and thing whatsoever requisite,
necessary, or proper to be done in the exercise of any of the rights and powers
herein granted, as fully to all intents and purposes as the undersigned might or
could do if personally present, with full power of revocation, hereby ratifying
and confirming all that each such attorneys-in-fact shall lawfully do or cause
to be done by virtue of this power of attorney and the rights and powers herein
granted. The undersigned acknowledges that neither the Corporation nor the
above-named individuals, in serving in such capacity at the request of the
undersigned, are assuming any of the undersigned's responsibilities to comply
with Section 16 of the Securities Exchange Act of 1934.

     The Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4, and 5 with respect to the
undersigned's holdings of and transactions in securities issued by the
Corporation, unless earlier revoked by the undersigned in a signed writing
delivered to the foregoing attorneys-in-fact.  This Power of Attorney revokes
all such special powers of attorney granted to individuals in the past to act on
behalf of the undersigned for the purposes stated above.

     IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of this 23rd day of July 2018.

                                            /s/ ARCILIA C. ACOSTA
                                            ---------------------------
                                            ARCILIA C. ACOSTA




                              CONFIRMING STATEMENT

  This Statement confirms that the undersigned has authorized and designated
Joseph L. McCormick and Brian K. Shore, to execute and file on the undersigned's
behalf all Forms 3, 4, and 5 (including any amendments thereto) that the
undersigned may be required to file with the United States Securities and
Exchange Commission as a result of the undersigned's ownership of or
transactions in securities of ONE Gas, Inc.  The authority of the above-named
individuals under this Statement shall continue until the undersigned is no
longer required to file Forms 3, 4, or 5 with regard to the undersigned's
ownership of or transactions in securities of ONE Gas, Inc. unless earlier
revoked in writing.  This Statement revokes all such special powers of attorney
granted to individuals in the past to act on behalf of the undersigned for the
purposes stated above.  The undersigned acknowledges that neither ONE Gas, Inc.
nor the above-named individuals are assuming any of the undersigned's
responsibilities to comply with Section 16 of the Securities Exchange Act of
1934.



                                            /s/ ARCILIA C. ACOSTA
                                            --------------------------
                                            ARCILIA C. ACOSTA


Dated:  July 23, 2018