OGS

ogs-202602180001587732false00015877322026-02-182026-02-18

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

(Date of report)February 18, 2026 (Date of earliest event reported)February 18, 2026

ONE Gas, Inc. (Exact name of registrant as specified in its charter)

Oklahoma001-3610846-3561936 (State or other jurisdiction(Commission(IRS Employer of incorporation)File Number)Identification No.)

15 East Fifth Street; Tulsa, OK (Address of principal executive offices)

74103 (Zip code)

(918) 947-7000 (Registrant’s telephone number, including area code)

Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communication pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act:

Title of each classTrading SymbolName of each exchange on which registered Common Stock, par value $0.01 per shareOGSNew York Stock Exchange NYSE Texas

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR §230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (17 CFR §240.12b-2).

☐ Emerging growth company

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

The information disclosed in Items 2.02 and 7.01, including Exhibit 99.1 hereto, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the Exchange Act), or otherwise subject to the liabilities under that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act except as expressly set forth by specific reference in such filing.

Item 2.02Results of Operations and Financial Condition

On February 18, 2026, we announced our results of operations for the fourth quarter and year ended December 31, 2025. The news release is furnished as Exhibit 99.1 and incorporated by reference herein.

Item 7.01Regulation FD Disclosure

On February 18, 2026, we announced our results of operations for the fourth quarter and year ended December 31, 2025. The news release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01Financial Statements and Exhibits

(d)Exhibits

Exhibit NumberDescription

99.1News release issued by ONE Gas, Inc. dated February 18, 2026.

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

2

SIGNATURE

Pursuant to the requirements of the Exchange Act, the registrant has duly caused this report to be signed on its behalf by the undersigned, hereunto duly authorized.

ONE Gas, Inc.

Date:February 18, 2026By:/s/ Christopher P. Sighinolfi Christopher P. Sighinolfi Senior Vice President and Chief Financial Officer

3

ogs-202511030001587732false00015877322025-11-032025-11-03

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

(Date of report)November 3, 2025 (Date of earliest event reported)November 3, 2025

ONE Gas, Inc. (Exact name of registrant as specified in its charter)

Oklahoma001-3610846-3561936 (State or other jurisdiction(Commission(IRS Employer of incorporation)File Number)Identification No.)

15 East Fifth Street; Tulsa, OK (Address of principal executive offices)

74103 (Zip code)

(918) 947-7000 (Registrant’s telephone number, including area code)

Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communication pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act:

Title of each classTrading SymbolName of exchange on which registered Common Stock, par value $0.01 per shareOGSNew York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR §230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (17 CFR §240.12b-2).

☐ Emerging growth company

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

The information disclosed in Items 2.02 and 7.01, including Exhibit 99.1 hereto, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the Exchange Act), or otherwise subject to the liabilities under that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act except as expressly set forth by specific reference in such filing.

Item 2.02Results of Operations and Financial Condition

On November 3, 2025, we announced our results of operations for the quarter ended September 30, 2025. The news release is furnished as Exhibit 99.1 and incorporated by reference herein.

Item 7.01Regulation FD Disclosure

On November 3, 2025, we announced our results of operations for the quarter ended September 30, 2025, narrowed 2025 financial guidance, and declared a cash dividend of 67 cents per share of common stock. The news release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 8.01Other Events

On November 3, 2025, our board of directors declared a cash dividend of 67 cents per share of common stock, payable December 1, 2025, to shareholders of record at the close of business on November 14, 2025.

Item 9.01Financial Statements and Exhibits

(d)Exhibits

Exhibit NumberDescription

99.1News release issued by ONE Gas, Inc. dated November 3, 2025.

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

2

SIGNATURE

Pursuant to the requirements of the Exchange Act, the registrant has duly caused this report to be signed on its behalf by the undersigned, hereunto duly authorized.

ONE Gas, Inc.

Date:November 3, 2025By:/s/ Christopher P. Sighinolfi Christopher P. Sighinolfi Senior Vice President and Chief Financial Officer

3

ogs-202508050001587732false00015877322025-08-052025-08-05

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

(Date of report)August 5, 2025 (Date of earliest event reported)August 5, 2025

ONE Gas, Inc. (Exact name of registrant as specified in its charter)

Oklahoma001-3610846-3561936 (State or other jurisdiction(Commission(IRS Employer of incorporation)File Number)Identification No.)

15 East Fifth Street; Tulsa, OK (Address of principal executive offices)

74103 (Zip code)

(918) 947-7000 (Registrant’s telephone number, including area code)

Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communication pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act:

Title of each classTrading SymbolName of exchange on which registered Common Stock, par value $0.01 per shareOGSNew York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR §230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (17 CFR §240.12b-2).

☐ Emerging growth company

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

The information disclosed in Items 2.02 and 7.01, including Exhibit 99.1 hereto, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the Exchange Act), or otherwise subject to the liabilities under that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act except as expressly set forth by specific reference in such filing.

Item 2.02Results of Operations and Financial Condition

On August 5, 2025, we announced our results of operations for the quarter ended June 30, 2025. The news release is furnished as Exhibit 99.1 and incorporated by reference herein.

Item 7.01Regulation FD Disclosure

On August 5, 2025, we announced our results of operations for the quarter ended June 30, 2025 and increased our 2025 financial guidance. The news release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01Financial Statements and Exhibits

(d)Exhibits

Exhibit NumberDescription

99.1News release issued by ONE Gas, Inc. dated August 5, 2025.

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

2

SIGNATURE

Pursuant to the requirements of the Exchange Act, the registrant has duly caused this report to be signed on its behalf by the undersigned, hereunto duly authorized.

ONE Gas, Inc.

Date:August 5, 2025By:/s/ Christopher P. Sighinolfi Christopher P. Sighinolfi Senior Vice President and Chief Financial Officer

3