One Gas 401(k) and pension plans

One Gas, Inc., Tulsa, OK. EIN 46-3561936. Annual reports 2009–2025. Also filed as Oneok, Inc.; One Gas Inc.; One Gas, Inc.

One Gas, Inc. has 2 active retirement plans on file. The largest is the One Gas, Inc. 401(k) Plan, with 4,629 participants and $1.0 billion in assets in 2025. Fidelity has been its recordkeeper since 2014.

Active plans: 2
Participants: 7,234
Plan assets: $1.8 billion
401(k) recordkeeper: Fidelity
Plans on file: 4
Industry: Utilities

All 4 plans

Active plans first

One Gas, Inc. 401(k) Plan

401(k) with ESOPActive

Active. The plan filed its annual report for the 2025 plan year.

Plan number: 002Employer EIN 46-3561936
Participants (2025): 4,629
Net assets (2025): $1.0 billion
Recordkeeper: Fidelity2014–2025
Plan administrator: One Gas, Inc. Benefits Committee
15 E 5TH ST.
Tulsa, OK 74103
(918) 947-7000As filed for 2025
In effect since: January 1, 2014

Plans merged into this one: One Gas, Inc. Profit Sharing Plan (2021).

Year by year, 2014 to 2025

Plan year	Participants	Net assets	Recordkeeper
2025	4,629	$1.0 billion	Fidelity
2024	4,552	$968 million	Fidelity
2023	4,562	$864 million	Fidelity
2022	4,415	$774 million	Fidelity
2021	4,218	$908 million	not listed
2020	4,077	$719 million	not listed
2019	4,046	$794 million	not listed
2018	3,917	$679 million	not listed
2017	3,785	$716 million	not listed
2016	3,699	$703 million	not listed
2015	3,650	$577 million	not listed
2014	3,523	$697 million	Fidelity

One Gas, Inc. Retirement Plan

Cash balance pension, frozenActive

Active. The plan filed its annual report for the 2024 plan year.

Plan number: 001Employer EIN 46-3561936
Participants (2024): 2,605
Net assets (2024): $726 million
Plan administrator: One Gas Inc Benefits Committee Plan Administrator
15 E 5TH ST
Tulsa, OK 74103
(918) 947-7000As filed for 2024
In effect since: January 1, 2014

Plans merged into this one: One Gas, Inc Texas Gas Service Retirement Plan (2015).

Year by year, 2014 to 2024

Plan year	Participants	Net assets	Recordkeeper
2024	2,605	$726 million	not listed
2023	2,970	$795 million	not listed
2022	3,045	$769 million	not listed
2021	3,105	$1.0 billion	not listed
2020	3,183	$987 million	not listed
2019	3,394	$908 million	not listed
2018	3,742	$815 million	not listed
2017	3,833	$881 million	not listed
2016	4,360	$738 million	not listed
2015	5,528	$785 million	not listed
2014	4,596	$810 million	not listed

One Gas, Inc. Profit Sharing Plan

Profit-sharing planMerged

Merged. In 2021 its assets moved to the One Gas, Inc. 401(k) Plan, sponsored by One Gas, Inc. (EIN 46-3561936, plan 002). Accounts moved with them, so that plan is the one to contact.

Plan number: 010Employer EIN 46-3561936
Participants (2020): 3,032
Net assets (2020): $78.5 million
Plan administrator: One Gas, Inc.
P.O. Box 21049
Tulsa, OK 74121
(918) 947-7000As filed for 2021
In effect since: January 1, 2014

Year by year, 2014 to 2021

Plan year	Participants	Net assets	Recordkeeper
2021	0	$0	not listed
2020	3,032	$78.5 million	not listed
2019	2,925	$71.7 million	not listed
2018	2,682	$53.0 million	not listed
2017	2,446	$49.2 million	not listed
2016	2,249	$36.9 million	not listed
2015	2,052	$25.3 million	not listed
2014	1,756	$21.1 million	not listed

One Gas, Inc Texas Gas Service Retirement Plan

Pension (defined benefit)Merged

Merged. In 2015 its assets moved to the One Gas, Inc. Retirement Plan, sponsored by One Gas, Inc. (EIN 46-3561936, plan 001). Accounts moved with them, so that plan is the one to contact.

Plan number: 005Employer EIN 46-3561936
Participants (2014): 727
Net assets (2014): $37.6 million
Last listed administrator: Bank of Oklahoma2009–2010
Plan administrator: One Gas, Inc
P.O. Box 21049
Tulsa, OK 74121
(918) 947-7000As filed for 2015
In effect since: December 1, 1958

Earlier sponsor: Oneok, Inc. (2009–2012).

Earlier plan names: Texas Gas Service Company Employees Retirement Income Plan; Oneok, Inc. Texas Gas Service Company Employees Retirement Income Plan; One Gas, Inc. Texas Gas Service Retirement Plan.

Year by year, 2009 to 2015

Plan year	Participants	Net assets	Recordkeeper
2015	0	$0	not listed
2014	727	$37.6 million	not listed
2013	770	$39.5 million	not listed
2012	814	$38.4 million	not listed
2011	870	$39.3 million	not listed
2010	901	$42.5 million	Bank of Oklahoma
2009	953	$39.0 million	Bank of Oklahoma

If you had money in one of these plans

Call Fidelity (fidelity.com), which runs the One Gas, Inc. 401(k) Plan. With your Social Security number and the plan name, it can tell you whether you still have a balance and, if not, where it went.
Or call the plan administrator listed on the plan below ((918) 947-7000). That number was filed for 2025; ask for the benefits or retirement plan office.
If your plan was merged, your account moved with it. Follow the link on the plan to the plan it went into, and contact that one.
Still stuck? The Department of Labor's benefits advisers help for free: askebsa.dol.gov or 1-866-444-3272. Never pay anyone to find your own money.

What these numbers are

They come from the Form 5500 annual reports each plan files with the Department of Labor, as the plan filed them. A plan year is usually a calendar year.
Participants counts everyone in the plan at year end: current employees, former employees who still have a balance or a pension coming, and retirees or beneficiaries being paid.
The recordkeeper is the service provider whose Schedule C entry says it keeps the plan's records. Small plans do not file Schedule C, so some plans show none.
We cannot see anyone's account. Only the plan or its recordkeeper can tell you your balance.

Sources: U.S. Department of Labor, Form 5500 datasets and PBGC trusteed plans. How we read them.