XML 41 R20.htm IDEA: XBRL DOCUMENT
v3.25.3

Retirement and Postretirement Employee Benefit Plans | 12 Months Ended
--- | ---
Sep. 30, 2025
Retirement Benefits [Abstract] |
Retirement and Postretirement Employee Benefit Plans | Retirement and Postretirement Employee Benefit Plans We have both funded and unfunded noncontributory defined benefit plans that together cover most of our employees. We also maintain a postretirement plan that provides health care benefits to retired employees. Finally, we sponsor a defined contribution plan that covers substantially all employees. These plans are discussed in further detail below. As a rate regulated entity, most of our net periodic pension and other postretirement benefits costs are recoverable through our rates over a period of up to 15 years. A portion of these costs are capitalized into our rate base or deferred as a regulatory asset or liability. The remaining costs are recorded as a component of operation and maintenance expense or other non-operating expense. Additionally, the amounts that have not yet been recognized in net periodic pension cost that have been recorded as regulatory assets or liabilities are as follows:
| Employee Pension Plan |  | Supplemental Executive Retirement Plans |  | Postretirement Plan |  | Total
| (In thousands)
September 30, 2025 |  |  |  |  |  |  |
Unrecognized prior service credit | $ | — |  |  | $ | — |  |  | $ | (9,984) |  |  | $ | (9,984) |
Unrecognized actuarial (gain) loss | (179,351) |  |  | 17,661 |  |  | (116,690) |  |  | (278,380) |
| $ | (179,351) |  |  | $ | 17,661 |  |  | $ | (126,674) |  |  | $ | (288,364) |
September 30, 2024 |  |  |  |  |  |  |
Unrecognized prior service credit | $ | — |  |  | $ | — |  |  | $ | (24,897) |  |  | $ | (24,897) |
Unrecognized actuarial (gain) loss | (126,989) |  |  | 16,136 |  |  | (111,500) |  |  | (222,353) |
| $ | (126,989) |  |  | $ | 16,136 |  |  | $ | (136,397) |  |  | $ | (247,250) |
Defined Benefit Plans Employee Pension Plan As of September 30, 2025, we maintained one cash balance defined benefit plan, the Atmos Energy Corporation Pension Account Plan (the Pension Plan). The Pension Plan was established effective January 1999 and covers most of the employees of Atmos Energy that were hired on or before September 30, 2010. Effective October 1, 2010, the Pension Plan was closed to new participants. The assets of the Pension Plan are held within the Atmos Energy Corporation Master Retirement Trust (the Master Trust). Opening account balances were established for participants as of January 1999 equal to the present value of their respective accrued benefits under the pension plans which were previously in effect as of December 31, 1998. The Pension Plan credits an allocation to each participant’s account at the end of each year according to a formula based on the participant’s age, service, and total pay (excluding incentive pay). In addition, at the end of each year, a participant’s account is credited with interest on the employee’s prior year account balance. Participants are fully vested in their account balances after three years of service and may choose to receive their account balances as a lump sum or an annuity. Generally, our funding policy is to contribute annually an amount in accordance with the requirements of the Employee Retirement Income Security Act of 1974 (ERISA), including the funding requirements under the Pension Protection Act of 2006 (PPA). However, additional voluntary contributions are made from time to time as considered necessary. Contributions are intended to provide not only for benefits attributed to service to date but also for those expected to be earned in the future. During fiscal 2025 we made no contributions to the Pension Plan and during fiscal 2024 we contributed $5.0 million in cash to the Pension Plan to achieve a desired level of funding while maximizing the tax deductibility of this payment. Based upon market conditions at September 30, 2025, the current funded position of the Pension Plan, and the funding requirements under the PPA, we do not anticipate a minimum required contribution for fiscal 2026. However, we may consider whether a voluntary contribution is prudent to maintain certain funding levels. We make investment decisions and evaluate performance of the assets in the Master Trust on a medium-term horizon of at least three to five years. We also consider our current financial status when making recommendations and decisions regarding the Master Trust’s assets. Finally, we strive to ensure the Master Trust’s assets are appropriately invested to maintain an acceptable level of risk and meet the Master Trust’s long-term asset investment policy adopted by the Qualified Retirement Plans and Trusts Committee, comprised of a group of executives appointed by the Board of Directors to oversee the Company's employee pension plan, defined contribution plan and postretirement benefit plan. To achieve these objectives, we invest the Master Trust’s assets in equity securities, fixed income securities, interests in commingled pension trust funds, other investment assets, and cash and cash equivalents. Investments in equity securities are diversified among the market’s various subsectors in an effort to diversify risk and maximize returns. Fixed income securities are invested in investment grade securities. Cash equivalents are invested in securities that either are short term (less than 180 days) or readily convertible to cash with modest risk. The following table presents asset allocation information for the Master Trust as of September 30, 2025 and 2024.
| Targeted Allocation Range |  | Actual Allocation September 30
Security Class | 2025 |  | 2024
Domestic equities | 35%-55% |  | 43.6% |  | 42.8%
International equities | 10%-20% |  | 15.5% |  | 15.8%
Fixed income | 5%-45% |  | 24.3% |  | 22.3%
Company stock | 0%-15% |  | 14.0% |  | 16.7%
Other assets | 0%-20% |  | 2.6% |  | 2.4%
At September 30, 2025 and 2024, the Pension Plan held 506,700 and 716,700 shares of our common stock which represented 14.0 percent and 16.7 percent of total Pension Plan assets. These shares generated dividend income for the Pension Plan of approximately $1.9 million and $2.3 million during fiscal 2025 and 2024. Our Pension Plan expenses and liabilities are determined on an actuarial basis and are affected by numerous assumptions and estimates including the market value of plan assets, estimates of the expected return on plan assets, and assumed discount rates and demographic data. We review the estimates and assumptions underlying our Pension Plan annually based upon a September 30 measurement date. The development of our assumptions is fully described in our significant accounting policies in Note 2 to the consolidated financial statements. The actuarial assumptions used to determine the pension asset for the Pension Plan was determined as of September 30, 2025 and 2024 and the actuarial assumptions used to determine the net periodic pension cost for the Pension Plan was determined as of September 30, 2024, 2023, and 2022. Additional assumptions are presented in the following table:
| Pension Asset |  | Pension Cost
| 2025 |  | 2024 |  | 2025 |  | 2024 |  | 2023
Discount rate | 5.45 | % |  | 5.02 | % |  | 5.02 | % |  | 6.10 | % |  | 5.66 | %
Rate of compensation increase | 3.50 | % |  | 3.50 | % |  | 3.50 | % |  | 3.50 | % |  | 3.50 | %
Expected return on plan assets | 6.50 | % |  | 6.50 | % |  | 6.50 | % |  | 6.25 | % |  | 6.25 | %
Interest crediting rate (1) | 4.69 | % |  | 4.69 | % |  | 4.69 | % |  | 4.69 | % |  | 4.69 | %
(1) The interest crediting rate assumption for the development of the fiscal 2025 pension asset is 4.73% for calendar year 2026, then reverting back to 4.69% for all future years. The following table presents the Pension Plan’s accumulated benefit obligation, projected benefit obligation, and funded status as of September 30, 2025 and 2024:
| 2025 |  | 2024
| (In thousands)
Accumulated benefit obligation | $ | 428,845 |  |  | $ | 448,353 |
Change in projected benefit obligation: |  |  |
Benefit obligation at beginning of year | $ | 470,902 |  |  | $ | 431,560 |
Service cost | 10,047 |  |  | 9,546 |
Interest cost | 23,164 |  |  | 25,731 |
Actuarial (gain) loss | (18,133) |  |  | 44,205 |
Benefits paid | (35,556) |  |  | (40,140) |
Benefit obligation at end of year | 450,424 |  |  | 470,902 |
Change in plan assets: |  |  |
Fair value of plan assets at beginning of year | 595,212 |  |  | 502,412 |
Actual return on plan assets | 64,847 |  |  | 127,940 |
Employer contributions | — |  |  | 5,000 |
Benefits paid | (35,556) |  |  | (40,140) |
Fair value of plan assets at end of year | 624,503 |  |  | 595,212 |
Reconciliation: |  |  |
Funded status | 174,079 |  |  | 124,310 |
Unrecognized prior service cost | — |  |  | — |
Unrecognized net loss | — |  |  | — |
Net amount recognized | $ | 174,079 |  |  | $ | 124,310 |
Net periodic pension cost for the Pension Plan for fiscal 2025, 2024, and 2023 is presented in the following table.
| Fiscal Year Ended September 30
| 2025 |  | 2024 |  | 2023
| (In thousands)
Components of net periodic pension cost: |  |  |  |  |
Service cost | $ | 10,047 |  |  | $ | 9,546 |  |  | $ | 10,805 |
Interest cost (1) | 23,164 |  |  | 25,731 |  |  | 24,924 |
Expected return on assets (1) | (30,618) |  |  | (28,808) |  |  | (29,113) |
Amortization of prior service credit (1) | — |  |  | — |  |  | (121) |
Recognized actuarial gain (1) | — |  |  | (67) |  |  | — |
Net periodic pension cost | $ | 2,593 |  |  | $ | 6,402 |  |  | $ | 6,495 |
(1) The components of net periodic cost other than the service cost component are included in the line item other non-operating income in the consolidated statements of comprehensive income or are capitalized on the consolidated balance sheets as a regulatory asset or liability, as described in Note 2 to the consolidated financial statements. The following tables set forth by level, within the fair value hierarchy, the Pension Plan's assets at fair value as of September 30, 2025 and 2024. As required by authoritative accounting literature, assets are categorized in their entirety based on the lowest level of input that is significant to the fair value measurement. The methods used to determine fair value for the assets held by the Pension Plan are fully described in Note 2 to the consolidated financial statements. Investments in our common/collective trusts and limited partnerships that are measured at net asset value per share equivalent are not classified in the fair value hierarchy. The net asset value amounts presented are intended to reconcile the fair value hierarchy to the total investments. In addition to the assets shown below, the Pension Plan had net accounts receivable of $5.1 million and $0.7 million at September 30, 2025 and 2024, which materially approximates fair value due to the short-term nature of these assets.
| Assets at Fair Value as of September 30, 2025
| Level 1 |  | Level 2 |  | Level 3 |  | Total
| (In thousands)
Investments: |  |  |  |  |  |  |
Common stocks | $ | 284,573 |  |  | $ | — |  |  | $ | — |  |  | $ | 284,573 |
Money market funds | — |  |  | 16,293 |  |  | — |  |  | 16,293 |
Registered investment companies | 123,022 |  |  | — |  |  | — |  |  | 123,022 |
Government securities: |  |  |  |  |  |  |
Mortgage-backed securities | — |  |  | 26,101 |  |  | — |  |  | 26,101 |
U.S. treasuries | 15,021 |  |  | 26 |  |  | — |  |  | 15,047 |
Corporate bonds | — |  |  | 32,517 |  |  | — |  |  | 32,517 |
Asset-backed securities | — |  |  | 1,475 |  |  | — |  |  | 1,475 |
Total investments measured at fair value | $ | 422,616 |  |  | $ | 76,412 |  |  | $ | — |  |  | 499,028 |
Investments measured at net asset value: |  |  |  |  |  |  |
Common/collective trusts (1) |  |  |  |  |  |  | 95,558 |
Limited partnerships (1) |  |  |  |  |  |  | 24,843 |
Total investments |  |  |  |  |  |  | $ | 619,429 |
| Assets at Fair Value as of September 30, 2024
| Level 1 |  | Level 2 |  | Level 3 |  | Total
| (In thousands)
Investments: |  |  |  |  |  |  |
Common stocks | $ | 289,301 |  |  | $ | — |  |  | $ | — |  |  | $ | 289,301 |
Money market funds | — |  |  | 14,542 |  |  | — |  |  | 14,542 |
Registered investment companies | 90,086 |  |  | — |  |  | — |  |  | 90,086 |
Government securities: |  |  |  |  |  |  |
Mortgage-backed securities | — |  |  | 24,383 |  |  | — |  |  | 24,383 |
U.S. treasuries | 9,398 |  |  | 27 |  |  | — |  |  | 9,425 |
Corporate bonds | — |  |  | 31,986 |  |  | — |  |  | 31,986 |
Total investments measured at fair value | $ | 388,785 |  |  | $ | 70,938 |  |  | $ | — |  |  | 459,723 |
Investments measured at net asset value: |  |  |  |  |  |  |
Common/collective trusts (1) |  |  |  |  |  |  | 111,103 |
Limited partnerships (1) |  |  |  |  |  |  | 23,665 |
Total investments |  |  |  |  |  |  | $ | 594,491 |
(1) The fair value of our common/collective trusts and limited partnerships are measured using the net asset value per share practical expedient. There are no redemption restrictions, redemption notice periods, or unfunded commitments for these investments. The redemption frequency is daily. Supplemental Executive Retirement Plans We have three nonqualified supplemental plans (the Supplemental Plans) which provide additional pension, disability, and death benefits to our officers and certain other employees of the Company. The Supplemental Executive Benefits Plan (SEBP) covers our corporate officers and certain other employees of the Company who were employed on or before August 12, 1998. The SEBP is a defined benefit arrangement which provides a benefit equal to 75 percent of covered compensation under which benefits paid from the underlying qualified defined benefit plan are an offset to the benefits under the SEBP. In August 1998, we adopted the Supplemental Executive Retirement Plan (SERP) (formerly known as the Performance-Based Supplemental Executive Benefits Plan), which covers all corporate officers selected to participate in the plan between August 12, 1998 and August 5, 2009. The SERP is a defined benefit arrangement which provides a benefit equal to 60 percent of covered compensation under which benefits paid from the underlying qualified defined benefit plan are an offset to the benefits under the SERP. Effective August 5, 2009, we adopted a new defined benefit Supplemental Executive Retirement Plan (the 2009 SERP), for corporate officers or any other employees selected at the discretion of the Board. Under the 2009 SERP, a nominal account has been established for each participant, to which the Company contributes at the end of each calendar year an amount equal to ten percent (25 percent for members of the Management Committee appointed on or after January 1, 2016) of the total of each participant’s base salary and cash incentive compensation earned during each prior calendar year, beginning December 31, 2009. The benefits vest after three years of service and attainment of age 55 and earn interest credits at the same annual rate as the Company’s Pension Plan. During fiscal 2024, we recognized settlement charges of $1.5 million and paid $9.6 million in lump sums in relation to the retirement of certain executives. During fiscal 2023, we recognized a settlement charge of $1.0 million and paid a $5.6 million lump sum in relation to the retirements of certain executives. We review the estimates and assumptions underlying our Supplemental Plans annually based upon a September 30 measurement date using the same techniques as our Pension Plan. The actuarial assumptions used to determine the pension liability for the Supplemental Plans were determined as of September 30, 2025 and 2024 and the actuarial assumptions used to determine the net periodic pension cost for the Supplemental Plans were determined as of September 30, 2024, 2023, and 2022. These assumptions are presented in the following table:
| Pension Liability |  | Pension Cost
| 2025 |  | 2024 |  | 2025 |  | 2024 |  | 2023
Discount rate (1) | 5.14 | % |  | 4.92 | % |  | 4.92 | % |  | 5.85 | % |  | 5.50 | %
Rate of compensation increase | 3.50 | % |  | 3.50 | % |  | 3.50 | % |  | 3.50 | % |  | 3.50 | %
Interest crediting rate (2) | 4.69 | % |  | 4.69 | % |  | 4.69 | % |  | 4.69 | % |  | 4.69 | %
(1) Reflects a weighted average discount rate for pension cost for fiscal 2024 and 2023 due to the settlements during the year. (2) The interest crediting rate assumption for the development of the fiscal 2025 pension liability is 4.73% for calendar year 2026, then reverting back to 4.69% for all future years. The following table presents the Supplemental Plans’ accumulated benefit obligation, projected benefit obligation, and funded status as of September 30, 2025 and 2024:
| 2025 |  | 2024
| (In thousands)
Accumulated benefit obligation | $ | 73,570 |  |  | $ | 71,003 |
Change in projected benefit obligation: |  |  |
Benefit obligation at beginning of year | $ | 71,944 |  |  | $ | 75,898 |
Service cost | 1,302 |  |  | 55 |
Interest cost | 3,488 |  |  | 4,024 |
Actuarial loss | 2,547 |  |  | 5,853 |
Benefits paid | (4,761) |  |  | (4,285) |
Settlements | — |  |  | (9,601) |
Benefit obligation at end of year | 74,520 |  |  | 71,944 |
Change in plan assets: |  |  |
Fair value of plan assets at beginning of year | — |  |  | — |
Employer contribution | — |  |  | — |
Benefits paid | — |  |  | — |
Settlements | — |  |  | — |
Fair value of plan assets at end of year | — |  |  | — |
Reconciliation: |  |  |
Funded status | (74,520) |  |  | (71,944) |
Unrecognized prior service cost | — |  |  | — |
Unrecognized net loss | — |  |  | — |
Accrued pension cost | $ | (74,520) |  |  | $ | (71,944) |
Assets for the Supplemental Plans are held in separate rabbi trusts. At September 30, 2025 and 2024, assets held in the rabbi trusts consisted of equity securities of $30.1 million and $31.1 million, which are included in our fair value disclosures in Note 17 to the consolidated financial statements. Net periodic pension cost for the Supplemental Plans for fiscal 2025, 2024, and 2023 is presented in the following table.
| Fiscal Year Ended September 30
| 2025 |  | 2024 |  | 2023
| (In thousands)
Components of net periodic pension cost: |  |  |  |  |
Service cost | $ | 1,302 |  |  | $ | 55 |  |  | $ | 845 |
Interest cost (1) | 3,488 |  |  | 4,024 |  |  | 4,227 |
Recognized actuarial loss (1) | 1,022 |  |  | 501 |  |  | 691 |
Settlements (1) | — |  |  | 1,529 |  |  | 1,030 |
Net periodic pension cost | $ | 5,812 |  |  | $ | 6,109 |  |  | $ | 6,793 |
(1) The components of net periodic cost other than the service cost component are included in the line item other non-operating income in the consolidated statements of comprehensive income or are capitalized on the consolidated balance sheets as a regulatory asset or liability, as described in Note 2 to the consolidated financial statements. Estimated Future Benefit Payments The following benefit payments for our defined benefit plans, which reflect expected future service, as appropriate, are expected to be paid in the following fiscal years:
| Pension Plan |  | Supplemental Plans
| (In thousands)
2026 | $ | 40,122 |  |  | $ | 6,277 |
2027 | 39,190 |  |  | 9,627 |
2028 | 38,729 |  |  | 28,392 |
2029 | 38,798 |  |  | 3,783 |
2030 | 38,777 |  |  | 3,615 |
2031-2035 | 178,831 |  |  | 31,031 |
Postretirement Benefits Plan We sponsor the Retiree Medical Plan for Retirees and Disabled Employees of Atmos Energy Corporation (the Retiree Medical Plan). This plan provides medical and prescription drug protection to all qualified participants based on their date of retirement. The Retiree Medical Plan provides different levels of benefits depending on the level of coverage chosen by the participants and the terms of predecessor plans. Effective January 1, 2022, the Retiree Medical Plan was amended to change the post-65 retiree coverage to Via Benefits with an Atmos Energy funded Health Reimbursement Account. Eligible post-65 retirees and post-65 spouses will be able to elect coverage through Via Benefits, including those that previously deferred or declined retiree coverage. Generally, our funding policy is to contribute annually an amount in accordance with the requirements of ERISA. However, additional voluntary contributions are made annually as considered necessary. Contributions are intended to provide not only for benefits attributed to service to date but also for those expected to be earned in the future. We expect to contribute between $13 million and $18 million to our Retiree Medical Plan during fiscal 2026. We maintain a formal investment policy with respect to the assets in our Retiree Medical Plan to ensure the assets funding the Retiree Medical Plan are appropriately invested to maintain an acceptable level of risk. We also consider our current financial status when making recommendations and decisions regarding the Retiree Medical Plan. We currently invest the assets funding our Retiree Medical Plan in diversified investment funds which consist of common stocks, preferred stocks, and fixed income securities. The diversified investment funds may invest up to 75 percent of assets in common stocks and convertible securities. The following table presents asset allocation information for the Retiree Medical Plan assets as of September 30, 2025 and 2024.
| Actual Allocation September 30
Security Class | 2025 |  | 2024
Diversified investment funds | 98.6% |  | 97.8%
Cash and cash equivalents | 1.4% |  | 2.2%
We review the estimates and assumptions underlying our Retiree Medical Plan annually based upon a September 30 measurement date using the same techniques as our Pension Plan and Supplemental Plans. The actuarial assumptions used to determine the postretirement asset for our Retiree Medical Plan were determined as of September 30, 2025 and 2024 and the actuarial assumptions used to determine the net periodic postretirement cost for the Retiree Medical Plan were determined as of September 30, 2024, 2023, and 2022. The assumptions are presented in the following table:
| Postretirement Asset |  | Postretirement Cost
| 2025 |  | 2024 |  | 2025 |  | 2024 |  | 2023
Discount rate | 5.47 | % |  | 5.01 | % |  | 5.01 | % |  | 6.06 | % |  | 5.61 | %
Expected return on plan assets | 5.14 | % |  | 5.14 | % |  | 5.14 | % |  | 4.94 | % |  | 4.94 | %
Initial trend rate | 7.00 | % |  | 6.75 | % |  | 6.75 | % |  | 6.50 | % |  | 6.25 | %
Ultimate trend rate | 5.00 | % |  | 5.00 | % |  | 5.00 | % |  | 5.00 | % |  | 4.75 | %
Ultimate trend reached in | 2034 |  | 2032 |  | 2032 |  | 2030 |  | 2029
The following table presents the Retiree Medical Plan’s benefit obligation and funded status as of September 30, 2025 and 2024:
| 2025 |  | 2024
| (In thousands)
Change in benefit obligation: |  |  |
Benefit obligation at beginning of year | $ | 269,391 |  |  | $ | 234,004 |
Service cost | 8,132 |  |  | 6,028 |
Interest cost | 13,463 |  |  | 14,034 |
Plan participants’ contributions | 1,993 |  |  | 2,102 |
Actuarial (gain) loss | (8,733) |  |  | 31,135 |
Benefits paid | (19,065) |  |  | (17,912) |
Plan amendments | 1,873 |  |  | — |
Benefit obligation at end of year | 267,054 |  |  | 269,391 |
Change in plan assets: |  |  |
Fair value of plan assets at beginning of year | 300,692 |  |  | 255,800 |
Actual return on plan assets | 21,500 |  |  | 47,857 |
Employer contributions | — |  |  | — |
Benefits paid | (2,808) |  |  | (2,965) |
Fair value of plan assets at end of year | 319,384 |  |  | 300,692 |
Reconciliation: |  |  |
Funded status | 52,330 |  |  | 31,301 |
Unrecognized transition obligation | — |  |  | — |
Unrecognized prior service cost | — |  |  | — |
Unrecognized net loss | — |  |  | — |
Accrued postretirement cost | $ | 52,330 |  |  | $ | 31,301 |
Net periodic postretirement cost for the Retiree Medical Plan for fiscal 2025, 2024, and 2023 is presented in the following table.
| Fiscal Year Ended September 30
| 2025 |  | 2024 |  | 2023
| (In thousands)
Components of net periodic postretirement cost: |  |  |  |  |
Service cost | $ | 8,132 |  |  | $ | 6,028 |  |  | $ | 6,183 |
Interest cost (1) | 13,463 |  |  | 14,034 |  |  | 13,911 |
Expected return on assets (1) | (15,325) |  |  | (12,511) |  |  | (11,215) |
Amortization of prior service credit (1) | (13,040) |  |  | (13,040) |  |  | (13,142) |
Recognized actuarial gain (1) | (9,716) |  |  | (10,872) |  |  | (7,452) |
Net periodic postretirement cost | $ | (16,486) |  |  | $ | (16,361) |  |  | $ | (11,715) |
(1) The components of net periodic cost other than the service cost component are included in the line item other non-operating income in the consolidated statements of comprehensive income or are capitalized on the consolidated balance sheets as a regulatory asset or liability, as described in Note 2 to the consolidated financial statements. We are currently recovering other postretirement benefits costs through our regulated rates in substantially all of our service areas under accrual accounting as prescribed by accounting principles generally accepted in the United States. Other postretirement benefits costs have been specifically addressed in rate orders in each jurisdiction served by our Kentucky/Mid-States, West Texas, Mid-Tex, and Mississippi Divisions as well as our Kansas jurisdiction and APT or have been included in a rate case and not disallowed. Management believes that this accounting method is appropriate and will continue to seek rate recovery of accrual-based expenses in its ratemaking jurisdictions that have not yet approved the recovery of these expenses. The following tables set forth by level, within the fair value hierarchy, the Retiree Medical Plan’s assets at fair value as of September 30, 2025 and 2024. The methods used to determine fair value for the assets held by the Retiree Medical Plan are fully described in Note 2 to the consolidated financial statements.
| Assets at Fair Value as of September 30, 2025
| Level 1 |  | Level 2 |  | Level 3 |  | Total
| (In thousands)
Investments: |  |  |  |  |  |  |
Money market funds | $ | — |  |  | $ | 4,428 |  |  | $ | — |  |  | $ | 4,428 |
Registered investment companies | 314,956 |  |  | — |  |  | — |  |  | 314,956 |
Total investments measured at fair value | $ | 314,956 |  |  | $ | 4,428 |  |  | $ | — |  |  | $ | 319,384 |
| Assets at Fair Value as of September 30, 2024
| Level 1 |  | Level 2 |  | Level 3 |  | Total
| (In thousands)
Investments: |  |  |  |  |  |  |
Money market funds | $ | — |  |  | $ | 6,633 |  |  | $ | — |  |  | $ | 6,633 |
Registered investment companies | 294,059 |  |  | — |  |  | — |  |  | 294,059 |
Total investments measured at fair value | $ | 294,059 |  |  | $ | 6,633 |  |  | $ | — |  |  | $ | 300,692 |
Estimated Future Benefit Payments The following benefit payments paid by the Company, retirees, and prescription drug subsidies for our Retiree Medical Plan, which reflect expected future service, as appropriate, are expected to be paid in the following fiscal years.
|  | Company Payments |  | Retiree Payments |  | Subsidy Payments |  | Total Postretirement Benefits
|  | (In thousands)
2026 |  | $ | 18,898 |  |  | $ | 2,425 |  |  | $ | — |  |  | $ | 21,323 |
2027 |  | 18,859 |  |  | 2,320 |  |  | — |  |  | 21,179 |
2028 |  | 18,783 |  |  | 2,186 |  |  | — |  |  | 20,969 |
2029 |  | 19,011 |  |  | 2,112 |  |  | — |  |  | 21,123 |
2030 |  | 19,364 |  |  | 2,083 |  |  | — |  |  | 21,447 |
2031-2035 |  | 104,216 |  |  | 10,770 |  |  | — |  |  | 114,986 |
Defined Contribution Plan The Atmos Energy Corporation Retirement Savings Plan and Trust (the Retirement Savings Plan) covers substantially all employees and is subject to the provisions of Section 401(k) of the Internal Revenue Code. Newly hired employees automatically become participants of the Retirement Savings Plan on the date of employment at a contribution rate of five percent. They are eligible to receive matching contributions immediately upon enrollment, which vest after completing one year of service. Participants may elect a salary reduction up to a maximum of 65 percent of eligible compensation, as defined by the Retirement Savings Plan, not to exceed the maximum allowed by the Internal Revenue Service. Participants who contribute less than 10 percent will have their contribution percent increased by one percent annually until a 10 percent salary deferral rate is achieved, unless the participant opts out of this election. We match 100 percent of a participant’s contributions, limited to five percent of the participant’s salary. Effective January 1, 2026, the matching contribution will be increased to a limit of six percent of the participant's salary. Additionally, employees hired on or after October 1, 2010 receive a fixed annual contribution of four percent of eligible earnings. The Retirement Savings Plan also contains an elective Roth deferral feature. Finally, participants are permitted to take out a loan against their accounts subject to certain restrictions. Matching and fixed annual contributions to the Retirement Savings Plan are expensed as incurred and amounted to $34.3 million, $26.8 million and $23.9 million for fiscal years 2025, 2024, and 2023. At September 30, 2025 and 2024, the Retirement Savings Plan held 1.1 percent and 1.2 percent of our outstanding common stock.

X
- References No definition available. + Details
Name: | us-gaap_CompensationAndRetirementDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure for retirement benefits. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (o) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (p) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (q) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 60 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480266/715-60-50-3 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480126/715-20-S99-2 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 70 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480794/715-70-50-1 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480482/715-20-55-17 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(03) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (l) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -Name Accounting Standards Codification -Publisher FASB -URI https://asc.fasb.org/715/tableOfContent Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iii) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (r)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (r)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration