# EDGAR Filing Document

**Accession Number:** 0001587732
**File Stem:** 0001193125-26-201586
**Filing Date:** 2026-5
**Character Count:** 4188
**Document Hash:** b5754f6be2c073996a42a5aa04c5de0e
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-201586.hdr.sgml**: 20260501

**ACCESSION NUMBER**: 0001193125-26-201586

**CONFORMED SUBMISSION TYPE**: DEFA14A

**PUBLIC DOCUMENT COUNT**: 3

**FILED AS OF DATE**: 20260501

**DATE AS OF CHANGE**: 20260501

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** ONE Gas, Inc.
- **CENTRAL INDEX KEY:** 0001587732
- **STANDARD INDUSTRIAL CLASSIFICATION:** NATURAL GAS DISTRIBUTION [4924]
- **ORGANIZATION NAME:** 01 Energy & Transportation
- **EIN:** 463561936
- **STATE OF INCORPORATION:** OK
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** DEFA14A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36108
- **FILM NUMBER:** 26933199

**BUSINESS ADDRESS:**
- **STREET 1:** 15 EAST FIFTH STREET
- **CITY:** TULSA
- **STATE:** OK
- **ZIP:** 74103
- **BUSINESS PHONE:** 918-947-7000

**MAIL ADDRESS:**
- **STREET 1:** 15 EAST FIFTH STREET
- **CITY:** TULSA
- **STATE:** OK
- **ZIP:** 74103

**UNITED STATES** 

**SECURITIES AND EXCHANGE COMMISSION** 

**Washington, D.C. 20549** 

**SCHEDULE 14A** 

**Proxy Statement Pursuant to Section 14(a) of the** 

**Securities Exchange Act of 1934** 

Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐

Check the appropriate box:

☐ Preliminary Proxy Statement

☐ **Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))** 

☐ Definitive Proxy Statement

☒ Definitive Additional Materials

☐ Soliciting Material under § 240.14a-12

## ONE Gas, Inc.
**(Name of Registrant as Specified In Its Charter)** 

**NOT APPLICABLE** 

**(Name of Person(s) Filing Proxy Statement, if other than the Registrant)** 

Payment of Filing Fee (Check all boxes that apply):

☒ No fee required

☐ Fee paid previously with preliminary materials

☐ Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11.

------

![LOGO](g143726g94v25.jpg)

15 East Fifth Street

Tulsa, OK 74103

918-947-7000 • onegas.com

May 1, 2026

Dear Fellow Shareholder:

We have previously provided you proxy materials for the ONE Gas, Inc. Annual Meeting of Shareholders to be held on May 21, 2026, at 9:00 a.m. CDT in a virtual-only meeting format with no physical location. Information on how to virtually attend and participate in the annual meeting is provided under "About the 2026 Annual Meeting" in the proxy statement at <u>www.proxydocs.com/ogs</u>. You will not be able to attend the 2026 Annual Meeting in person.

According to our latest records we have not yet received your vote. The Annual Meeting is now only a short time away and your vote is important. In the event that your proxy materials have been misplaced, we are enclosing for your use a duplicate Voting Instruction Form and return envelope.

**Please follow the telephone or internet voting instructions on your Voting Instruction Form or sign and date the enclosed Voting Instruction Form and vote your shares today.** In the event that two voting forms are received from you, the one bearing the latest date will be counted, as it automatically revokes all prior votes.

If you hold your shares in the name of a brokerage firm, your broker cannot vote your shares on certain proposals unless your broker receives your specific instructions.

Your board of directors recommends that you vote:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(1) **FOR** the election of eight director nominees named in the proxy statement to serve on our board for a one-year term;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(2) **FOR** the ratification of the selection of PricewaterhouseCoopers LLP as our independent registered public
accounting firm for the year ending December 31, 2026;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(3) **FOR** the amendment and restatement of the Employee Stock Purchase Plan to authorize an additional 700,000
shares of ONE Gas, Inc. common stock for issuance under the plan; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(3) **FOR** the advisory proposal to approve our executive compensation.

Thank you for voting and for your continued support.

Sincerely,

![LOGO](g143726g10c03.jpg)

John W. Gibson,

Chair of the Board