ONE Gas, Inc.

Previous wording

Oklahoma - On February 26, 2026, Oklahoma Natural Gas filed its required PBRC application for the year ended December 31, 2025. The filed request included a $28.7 million base rate revenue increase, $2.6 million energy efficiency incentive, and $14.4 million of estimated EDIT to be credited to customers in 2027. A hearing before the administrative law judge is scheduled for June 11, 2026. Rates may be implemented subject to refund on June 26, 2026.

Current wording

Oklahoma - On February 26, 2026, Oklahoma Natural Gas filed its required PBRC application for the year ended December 31, 2025. The filed request included a $28.7 million base rate revenue increase, $2.6 million energy efficiency incentive, and $14.4 million of estimated EDIT to be credited to customers in 2027. At the hearing on June 11, 2026, the administrative law judge recommended approval of the application as filed. Subsequent to the hearing, exceptions to the administrative law judge’s oral ruling were filed at the OCC as well as an appeal to the Oklahoma Supreme Court. Interim rates subject to refund were implemented on June 26, 2026, in compliance with the PBRC tariff.

Previous wording

Texas - In March 2026, Texas Gas Service made a GRIP filing for all customers requesting a $36.9 million increase to be effective in July 2026.

Current wording

Texas - In March 2026, Texas Gas Service made a GRIP filing for all customers requesting a $36.9 million increase to be effective in July 2026. In June 2026, the RRC approved an increase of $36.9 million, and new rates became effective in July 2026.

Previous wording

Selected Financial Results -For the three months ended March 31, 2026, net income was $128.7 million, or $2.04 per diluted share, compared with $119.4 million, or $1.98 per diluted share in the same period last year. Adjusted net income was $133.4 million, or $2.11 adjusted net income per share, compared with adjusted net income of $120.1 million, or $1.99 adjusted net income per share, in the same period last year. See the “Non‑GAAP Financial Measures” section for a reconciliation of the Company’s GAAP net income and GAAP EPS to adjusted net income and adjusted net income per share.

Current wording

Selected Financial Results -For the three months ended June 30, 2026, net income was $46.8 million, or $0.74 per diluted share, compared with $32.0 million, or $0.53 per diluted share, in the same period last year. Adjusted net income was $52.1 million, or $0.82 adjusted net income per diluted share, for the three months ended June 30, 2026 compared with adjusted net income of $32.7 million, or $0.54 adjusted net income per diluted share, in the same period last year. For the six months ended June 30, 2026, net income was $175.5 million, or $2.78 per diluted share, compared with $151.5 million, or $2.51 per diluted share, in the same period last year. Adjusted net income was $185.5 million, or $2.94 adjusted net income per diluted share, for the six months ended June 30, 2026 compared with adjusted net income of $152.8 million, or $2.53 adjusted net income per diluted share, in the same period last year. See the “Non-GAAP Financial Measures” section for a reconciliation of the Company’s GAAP net income and GAAP EPS to adjusted net income and adjusted net income per share.

Previous wording

Operating income increased $9.1 million for the three months ended March 31, 2026, compared with the same period last year, due primarily to an increase of $27.3 million in revenue from new rates.

Current wording

Operating income increased $10.7 million for the three months ended June 30, 2026, compared with the same period last year, due primarily to the following:

Previous wording

•an increase of $6.8 million in employee-related costs due, in part, to planned investments in the Company’s workforce;

Current wording

•an increase of $7.4 million in employee-related costs;

Previous wording

•an increase of $1.3 million in outside services; and

Current wording

•an increase of $1.1 million in outside services; and

Previous wording

•a decrease of $8.9 million in revenue due to lower sales and transport volumes, net of the impact of weather normalization mechanisms.

Current wording

•a decrease of $10.6 million in revenue due to lower sales and transport volumes, net of the impact of weather normalization mechanisms.

Previous wording

Weather across our service territories for the first quarter of 2026 was 24.6 percent warmer than the prior year. The impact on operating income was tempered by our weather normalization mechanisms.

Current wording

Weather across our service territories was 28 percent warmer than the prior year for the three months ended June 30, 2026 and 25 percent warmer than the prior year for the six months ended June 30, 2026. The impact on operating income was mitigated by our weather normalization mechanisms.

Previous wording

Other Factors Affecting Net Income - Other factors that affected net income for the three months ended March 31, 2026, compared to the same period last year, include a decrease of $2.6 million in other income (expense), net due primarily to a $1.5 million decrease in net periodic benefit credit other than service costs and a $0.9 million decrease in the market value of investments associated with our nonqualified deferred compensation plans.

Current wording

Other Factors Affecting Net Income - Other factors that affected net income for the three months ended June 30, 2026, compared to the same period last year, include an increase of $2.6 million in other income (expense), net due primarily to a credit of $2.4 million due to the change in federal tax regulation for securitization, a $1.7 million increase in the market value of investments associated with our nonqualified deferred compensation plan, partially offset by a $1.3 million decrease in net periodic benefit credit other than service costs.

Previous wording

Additionally, net income for the three months ended March 31, 2026, compared with the same period last year, includes a decrease in interest expense, net of $3.3 million due primarily to a lower weighted average interest rate on commercial paper borrowings and the implementation of Texas Rule House Bill 4384.

Current wording

Additionally, net income for the three and six months ended June 30, 2026, compared with the same periods last year, includes decreases in interest expense, net of $4.2 million and $7.5 million, respectively, due primarily to a lower weighted-average interest rate on commercial paper borrowings and the implementation of Texas House Bill 4384.

Previous wording

EDIT - Income tax expense reflects credits for the amortization of the regulatory liability associated with EDIT that were returned to customers of $9.5 million and $8.1 million for the three months ended March 31, 2026 and 2025, respectively.

Current wording

EDIT - Income tax expense reflects credits for the amortization of the regulatory liability associated with EDIT that were returned to customers of $3.3 million and $2.1 million for the three months ended June 30, 2026 and 2025, respectively, and credits of $12.8 million and $10.2 million for the six months ended June 30, 2026 and 2025, respectively.

Previous wording

Capital expenditures and asset removal costs were $8.1 million lower for the three months ended March 31, 2026, compared with the same period last year. Our full-year capital expenditures and asset removal costs are expected to be approximately $800 million for 2026.

Current wording

Capital expenditures and asset removal costs were $1.8 million and $9.9 million lower for the three and six months ended June 30, 2026, compared with the same periods last year. Our full-year capital expenditures and asset removal costs are expected to be approximately $800 million for 2026.

Previous wording

Non-GAAP Financial Measures -Adjusted net income and adjusted net income per share are calculated as GAAP net income plus the deferral of an equity portion of a carrying cost attributable to shareholders’ investment capitalized for regulatory purposes but not for financial reporting purposes. These carrying costs relate to property, plant and equipment that has been placed in service, but not yet reflected in base rates. Adjusted net income and adjusted net income per share should not be considered in isolation or as a substitute for GAAP net income or GAAP EPS.

Current wording

Non-GAAP Financial Measures -Adjusted net income and adjusted net income per share are calculated as GAAP net income plus the deferral of an equity portion of a carrying cost attributable to shareholders’ investment capitalized for regulatory purposes but not for financial reporting purposes. These carrying costs relate to property, plant and equipment that has been placed in service, but not yet reflected in Texas rates. Property, plant and equipment placed in service may vary by quarter based on the timing and complexity of projects, weather impacts, construction completion schedules, contractor activities, and other operational factors. During the three months ended June 30, 2026, we placed $53.8 million of property, plant and equipment in service eligible for this treatment, compared with $62.6 million in the same period last year. For the six months ended June 30, 2026, we placed $125.3 million of property, plant and equipment in service eligible for this treatment, compared with $125.5 million in the same period last year. Adjusted net income and adjusted net income per share should not be considered in isolation or as a substitute for GAAP net income or GAAP EPS.

Previous wording

The increase in the average number of customers for the periods presented is due primarily to the connection of new customers resulting from the extension and expansion of our system in our service areas. For the three months ended March 31, 2026, our average customer count includes approximately 4,800 new customer connections during the period. For the year ended December 31, 2025, our average customer count included approximately 23,000 new customer connections.

Current wording

The increase in the average number of customers for the periods presented is due primarily to the connection of new customers resulting from the extension and expansion of our system in our service areas. For the three months ended June 30, 2026, our average customer count includes approximately 4,800 new customer connections in the period. For the six months ended June 30, 2026, our average customer count includes approximately 9,600 new customer connections in the period. For the year ended December 31, 2025, our average customer count included approximately 23,000 new customer connections.

Previous wording

Actual HDDs are based on the quarter-to-date weighted average of:

Current wording

Actual HDDs are based on the quarter weighted average of:

Previous wording

The ONE Gas Credit Agreement contains certain financial, operational, and legal covenants. Among other things, these covenants include maintaining ONE Gas’ total debt-to-capital ratio, excluding the debt of KGSS-I, of no more than 70 percent at the end of any calendar quarter. At March 31, 2026, our total debt-to-capital ratio, excluding KGSS-I, was 47.1 percent and we were in compliance with all covenants under the ONE Gas Credit Agreement. We may reduce the unutilized portion of the ONE Gas Credit Agreement in whole or in part without premium or penalty. The ONE Gas Credit Agreement contains customary events of default. Upon the occurrence of certain events of default, the obligations under the ONE Gas Credit Agreement may be accelerated and the commitments may be terminated.

Current wording

The ONE Gas Credit Agreement contains certain financial, operational, and legal covenants. Among other things, these covenants include maintaining ONE Gas’ total debt-to-capital ratio, excluding the debt of KGSS-I, of no more than 70 percent at the end of any calendar quarter. At June 30, 2026, our total debt-to-capital ratio, excluding KGSS-I, was 47.1 percent and we were in compliance with all covenants under the ONE Gas Credit Agreement. We may reduce the unutilized portion of the ONE Gas Credit Agreement in whole or in part without premium or penalty. The ONE Gas Credit Agreement contains customary events of default. Upon the occurrence of certain events of default, our obligations under the ONE Gas Credit Agreement may be accelerated and the commitments may be terminated.

Previous wording

Under our commercial paper program, we may issue unsecured commercial paper up to the maximum amount of $1.5 billion to fund short-term borrowing needs. The maturities of the commercial paper vary but may not exceed 270 days from the date of issue. Commercial paper is generally sold at par less a discount representing an interest factor. At March 31, 2026 and December 31, 2025, we had $759.7 million and $737.4 million of commercial paper outstanding with a weighted-average interest rate of 4.14 percent and 3.94 percent, respectively.

Current wording

Under our commercial paper program, we may issue unsecured commercial paper up to the maximum amount of $1.5 billion to fund short-term borrowing needs. The maturities of the commercial paper vary but may not exceed 270 days from the date of issue. Commercial paper is generally sold at par less a discount representing an interest factor. At June 30, 2026 and December 31, 2025, we had $770.8 million and $737.4 million of commercial paper outstanding with a weighted-average interest rate of 4.09 percent and 3.94 percent, respectively.

Previous wording

At-the-Market Equity Program- In February 2026, we entered into an at-the-market equity distribution agreement under which we may issue and sell shares of our common stock with an aggregate offering price up to $225 million. Sales of common stock are made by means of ordinary brokers’ transactions on the NYSE and the NYSE Texas, in block transactions or as otherwise agreed to between us and the sales agent. We are under no obligation to offer and sell common stock under the program. At March 31, 2026, we had $204.4 million of equity available for issuance under the program.

Current wording

At-the-Market Equity Program- In February 2026, we entered into an at-the-market equity distribution agreement under which we may issue and sell shares of our common stock with an aggregate offering price up to $225 million. Sales of common stock are made by means of ordinary brokers’ transactions on the NYSE and the NYSE Texas, in block transactions or as otherwise agreed to between us and the sales agent. We are under no obligation to offer and sell common stock under the program. At June 30, 2026, we had $204.4 million of equity available for issuance under the program. Had we fully settled all 506,607 shares sold under our forward sale agreements, as of June 30, 2026, we would have generated net proceeds of approximately $41.5 million.

Previous wording

Operating cash flows were lower for the three months ended March 31, 2026, compared with the prior period, due primarily to working capital changes related to an increase in regulatory assets.

Current wording

Operating cash flows were lower for the six months ended June 30, 2026, compared with the prior period, due primarily to working capital changes related to the recovery of regulatory assets, net.

Previous wording

Investing Cash Flows - Cash used in investing activities decreased for the three months ended March 31, 2026, compared with the prior period, due primarily to the timing of capital expenditures for system integrity and extension of service to new areas.

Current wording

Investing Cash Flows - Cash used in investing activities decreased for the six months ended June 30, 2026, compared with the prior period, due primarily to the timing of capital expenditures for system integrity and extension of service to new areas.

Previous wording

Financing Cash Flows - Cash used in financing activities decreased for the three months ended March 31, 2026, compared with the prior period, due primarily to higher net commercial paper repayments in 2025.

Current wording

Financing Cash Flows - Cash used in financing activities decreased for the six months ended June 30, 2026, compared with the prior period, due primarily to higher net commercial paper repayments in 2025.

Previous wording

Environmental Matters - We are subject to multiple laws and regulations regarding protection of the environment and natural and cultural resources, which affect many aspects of our present and future operations. Regulated activities include, but are not limited to, those involving air emissions, storm water and wastewater discharges, handling and disposal of solid and hazardous wastes, wetland preservation, plant and wildlife protection, hazardous materials use, storage, and transportation, and pipeline and facility construction. These laws and regulations require us to obtain and/or comply with a wide variety of environmental clearances, registrations, licenses, permits, and other approvals. Failure to comply with these laws, regulations, licenses, and permits or the discovery of presently unknown environmental conditions may expose us to fines, penalties, and/or interruptions in our operations that could be material to our results of operations. In addition, emission controls and/or other regulatory or permitting mandates under the CAA and other similar federal and state laws could require unexpected capital expenditures. We cannot assure that existing environmental statutes and regulations will not be revised or that new regulations will not be adopted or become applicable to us. Revised or additional statutes or regulations that result in increased compliance costs or additional operating restrictions could have a material adverse effect on our business, financial condition, and results of operations. Our expenditures for environmental investigation and remediation compliance to date have not been significant in relation to our financial position, results of operations, or cash flows, and our expenditures related to environmental matters had no material effects on earnings or cash flows during the three months ended March 31, 2026 and 2025.

Current wording

Environmental Matters - We are subject to multiple laws and regulations regarding protection of the environment and natural and cultural resources, which affect many aspects of our present and future operations. Regulated activities include, but are not limited to, those involving air emissions, storm water and wastewater discharges, handling and disposal of solid and hazardous wastes, wetland preservation, plant and wildlife protection, hazardous materials use, storage, and transportation, and pipeline and facility construction. These laws and regulations require us to obtain and/or comply with a wide variety of environmental clearances, registrations, licenses, permits, and other approvals. Failure to comply with these laws, regulations, licenses, and permits or the discovery of presently unknown environmental conditions may expose us to fines, penalties, and/or interruptions in our operations that could be material to our results of operations. In addition, emission controls and/or other regulatory or permitting mandates under the CAA and other similar federal and state laws could require unexpected capital expenditures. We cannot assure that existing environmental statutes and regulations will not be revised or that new regulations will not be adopted or become applicable to us. Revised or additional statutes or regulations that result in increased compliance costs or additional operating restrictions could have a material adverse effect on our business, financial condition, and results of operations. Our expenditures for environmental investigation and remediation compliance to date have not been significant in relation to our financial position, results of operations, or cash flows, and our expenditures related to environmental matters had no material effects on earnings or cash flows during the three and six months ended June 30, 2026, and 2025.

Previous wording

Pursuant to the AAO, costs approved for recovery in a future rate proceeding are to be amortized over a 15-year period. The unamortized amounts are not included in rate base or accumulate carrying charges. Following a determination that future investigation and remediation work approved by the KDHE exceeds $32.0 million, net of any related insurance recoveries, Kansas Gas Service is required to file an application with the KCC for approval to increase the $32.0 million cap. At March 31, 2026 and December 31, 2025, we have deferred $30.6 million and $30.1 million, respectively, for accrued investigation and remediation costs, net of insurance proceeds, pursuant to our AAO.

Current wording

Pursuant to the AAO, costs approved for recovery in a future rate proceeding are to be amortized over a 15-year period. The unamortized amounts are not included in rate base or accumulate carrying charges. Following a determination that future investigation and remediation work approved by the KDHE exceeds $32.0 million, net of any related insurance recoveries, Kansas Gas Service is required to file an application with the KCC for approval to increase the $32.0 million cap. At June 30, 2026 and December 31, 2025, we have deferred $30.3 million and $30.1 million, respectively, for accrued investigation and remediation costs, net of insurance proceeds, pursuant to our AAO.

Previous wording

We also own or retain legal responsibility for certain environmental conditions at a former MGP site in Texas. At the request of the TCEQ, we began investigating the level and extent of contamination associated with the site under their Texas Risk Reduction Program. A preliminary site investigation revealed that this site contains contaminants generally associated with MGP sites and is subject to control or remediation under various environmental laws and regulations. At March 31, 2026, estimated costs associated with expected remediation activities for this site are not material.

Current wording

We also own or retain legal responsibility for certain environmental conditions at a former MGP site in Texas. At the request of the TCEQ, we began investigating the level and extent of contamination associated with the site under their Texas Risk Reduction Program. A preliminary site investigation revealed that this site contains contaminants generally associated with

Previous wording

Our expenditures for environmental evaluation, mitigation, remediation, and compliance to date have not been significant in relation to our financial position, results of operations, or cash flows, and our expenditures related to environmental matters had no material effects on earnings or cash flows during the three months ended March 31, 2026 and 2025. The reserve for remediation of our MGP sites was $13.2 million and $13.7 million at March 31, 2026 and December 31, 2025, respectively.

Current wording

Our expenditures for environmental evaluation, mitigation, remediation, and compliance to date have not been significant in relation to our financial position, results of operations, or cash flows, and our expenditures related to environmental matters had no material effects on earnings or cash flows during the three and six months ended June 30, 2026, and 2025. The reserve for remediation of our MGP sites was $13.0 million and $13.7 million at June 30, 2026 and December 31, 2025, respectively.

Previous wording

Environmental Footprint - We cannot assure that existing environmental statutes and regulations will not be revised or that new regulations will not be adopted or become applicable to us. Revised or additional regulations that result in increased compliance costs or additional operating restrictions could have a material adverse effect on our business, financial condition, and results of operations. Our expenditures for environmental investigation and remediation compliance to date have not been significant in relation to our financial position, results of operations, or cash flows, and our expenditures related to environmental matters had no material effects on earnings or cash flows for the three months ended March 31, 2026 and 2025.

Current wording

Environmental Footprint - We cannot assure that existing environmental statutes and regulations will not be revised or that new regulations will not be adopted or become applicable to us. Revised or additional regulations that result in increased compliance costs or additional operating restrictions could have a material adverse effect on our business, financial condition, and results of operations. Our expenditures for environmental investigation and remediation compliance to date have not been significant in relation to our financial position, results of operations, or cash flows, and our expenditures related to environmental matters had no material effects on earnings or cash flows for the three and six months ended June 30, 2026, and 2025.

Previous wording

PHMSA promulgates various regulations related to pipeline safety. As part of the Consolidated Appropriations Act, 2021, the PIPES Act reauthorized PHMSA through 2023 and directed the agency to move forward with several regulatory actions. Outstanding regulatory actions include the “Pipeline Safety: Safety of Gas Distribution Pipelines” and “Pipeline Safety: Gas Pipeline Leak Detection” proposed rulemakings. The “Pipeline Safety: Gas Pipeline Leak Detection” proposed rule would require operators of new and existing transmission and distribution pipeline facilities to conduct certain leak detection and repair programs and require facility inspection and maintenance plans to align with those regulations. On January 20, 2025, an executive order began a regulatory freeze on all rulemakings that were not yet effective pending further review. To the extent such rulemakings impose more stringent requirements on our facilities, we may be required to incur expenditures that may be material.

Current wording

PHMSA promulgates various regulations related to pipeline safety. As part of the Consolidated Appropriations Act, 2021, the PIPES Act reauthorized PHMSA through 2023 and directed the agency to move forward with several regulatory actions. Outstanding regulatory actions include the “Pipeline Safety: Safety of Gas Distribution Pipelines” and “Pipeline Safety: Gas Pipeline Leak Detection” proposed rulemakings. On May 28, 2026, PHMSA hosted a meeting of the Gas Pipeline Advisory Committee to cover the proposed “Pipeline Safety: Safety of Gas Distribution Pipelines” rule. PHMSA is anticipating publishing the final rule to the Federal Register in December of 2026. The “Pipeline Safety: Gas Pipeline Leak Detection” proposed rule would require operators of new and existing transmission and distribution pipeline facilities to conduct certain leak detection and repair programs and require facility inspection and maintenance plans to align with those regulations. On January 20, 2025, an executive order began a regulatory freeze on all rulemakings that were not yet effective pending further review. On July 8, 2026, PHMSA published the NPRM for Gas Transmission Pipelines Repair Criteria in the Federal Register. This rule proposes to modernize and clarify anomaly response criteria. To the extent such rulemakings impose more stringent requirements on our facilities, we may be required to incur expenditures that may be material.

Previous wording

•indebtedness, which could make us more vulnerable to general adverse economic and industry conditions, limit our ability to borrow additional funds and/or place us at competitive disadvantage compared with competitors;

Current wording

•indebtedness, which could make us more vulnerable to general adverse economic and industry conditions, limit our ability to borrow additional funds and/or place us at a competitive disadvantage compared with competitors;