OGE ENERGY CORP.

Previous wording

OGE Energy's purpose is to energize life, providing life-sustaining and life-enhancing products and services that enrich its communities, encouraging growth and a higher quality of life. OGE Energy's purpose comes with a balanced approach to multifaceted stewardship: keeping its employees (internally referred to as "members") safe, reducing its environmental impact, strengthening its diverse communities and ensuring its effective corporate governance. OGE Energy's business model is centered around growth and sustainability for members, communities and customers and the owners of OGE Energy, its shareholders. OGE Energy is focused on creating long-term shareholder value by targeting the consistent growth of consolidated earnings per share of five to seven percent, supported by strong load growth enabled by low customer rates and a strategy of investing in lower risk infrastructure projects that improve the economic vitality of the communities it serves in Oklahoma and Arkansas. OGE Energy's long-term sustainability is predicated on providing exceptional customer experiences, strengthening the energy grid, investing in proven technologies to meet generation capacity needs, environmental stewardship, strong governance practices and caring for and supporting its members and communities. Further discussion of OGE Energy's strategy can be found in its 2024 Form 10-K.

Current wording

OGE Energy's purpose is to energize life, providing life-sustaining and life-enhancing products and services that enrich its communities, encouraging growth and a higher quality of life. OGE Energy's purpose comes with a balanced approach to multifaceted stewardship: keeping its employees (internally referred to as "members") safe, reducing its environmental impact, strengthening its diverse communities and ensuring its effective corporate governance. OGE Energy's business model is centered around growth and sustainability for members, communities and customers and the owners of OGE Energy, its shareholders. OGE Energy is focused on creating long-term shareholder value by targeting the consistent growth of consolidated earnings per share of five to seven percent through 2030, and consolidated earnings per share in the top half of the range in 2027 and 2028, supported by expected strong load growth enabled by low customer rates and a strategy of investing in lower risk infrastructure projects that improve the economic vitality of the communities it serves in Oklahoma and Arkansas. OGE Energy's long-term sustainability is predicated on providing exceptional customer engagement, strengthening the energy grid, investing in proven technologies to meet generation capacity needs, environmental stewardship, strong governance practices and caring for and supporting its members and communities. Further discussion of OGE Energy's strategy can be found in its 2025 Form 10-K.

Previous wording

OGE Energy's net income was $231.3 million, or $1.14 per diluted share, during the three months ended September 30, 2025 as compared to $218.7 million, or $1.09 per diluted share, during the same period in 2024. The increase in net income of $12.6 million, or $0.05 per diluted share, is further discussed below.

Current wording

OGE Energy's net income was $50.2 million, or $0.24 per diluted share, during the three months ended March 31, 2026 as compared to $62.7 million, or $0.31 per diluted share, during the same period in 2025. The decrease in net income of $12.5 million, or $0.07 per diluted share, is further discussed below.

Previous wording

An increase in net income at OG&E of $17.9 million, or $0.08 per diluted share of OGE Energy's common stock, was primarily due to higher operating revenues (excluding the impact of recoverable fuel, purchased power and direct transmission expense not impacting earnings) driven by the recovery of capital investments, which offset the impact of milder weather, partially offset by higher operation and maintenance expense, income tax expense, and lower net other income.

Current wording

A decrease in net income at OG&E of $13.1 million, or $0.07 per diluted share of OGE Energy's common stock, was primarily due to lower operating revenues (excluding the impact of recoverable fuel, purchased power and direct transmission expense not impacting earnings) driven by milder weather and higher other operation and maintenance expense, partially offset by the deferral of certain interest expense to a regulatory asset in accordance with Oklahoma PISA.

Previous wording

OGE Energy’s 2025 consolidated earnings guidance remains projected to be in the top half of its original 2025 earnings guidance range of $2.21 to $2.33 per average diluted share. This guidance assumes, among other things, approximately 202.1 million average diluted shares outstanding and normal weather for the remainder of the year. OG&E has significant seasonality in its earnings due to weather on a year-over-year basis. See OGE Energy's 2024 Form 10-K for other key factors and assumptions underlying its 2025 guidance.

Current wording

OGE Energy’s consolidated earnings guidance remains unchanged from OGE Energy's original 2026 earnings guidance range of $494 million to $514 million, or $2.38 to $2.48 per average diluted share. OG&E is projected to earn approximately $533 million, or $2.57 per average diluted share. A loss of $30 million, or $0.14 per average diluted share is projected for other operations (primarily the holding company). This guidance assumes, among other things, approximately 207.3 million average diluted shares outstanding and normal weather for the remainder of the year. OG&E has significant seasonality in its earnings due to weather on a year-over-year basis. See OGE Energy's 2025 Form 10-K for other key factors and assumptions underlying its 2026 guidance.

Previous wording

The following discussion and analysis presents factors that affected the Registrants' results of operations for the three and nine months ended September 30, 2025 as compared to the same period in 2024 and the Registrants' financial position at September 30, 2025. Due to seasonal fluctuations and other factors, the Registrants' operating results for the three and nine months ended September 30, 2025 are not necessarily indicative of the results that may be expected for the year ending December 31, 2025 or for any future period. The following information should be read in conjunction with the condensed financial statements and notes thereto. Known trends and contingencies of a material nature are discussed to the extent considered relevant.

Current wording

The following discussion and analysis presents factors that affected the Registrants' results of operations for the three months ended March 31, 2026 as compared to the same period in 2025 and the Registrants' financial position at March 31, 2026. Due to seasonal fluctuations and other factors, the Registrants' operating results for the three months ended March 31, 2026 are not necessarily indicative of the results that may be expected for the year ending December 31, 2026 or for any future period. The following information should be read in conjunction with the condensed financial statements and notes thereto. Known trends and contingencies of a material nature are discussed to the extent considered relevant.

Previous wording

OG&E's net income increased $17.9 million, or 8.0 percent, and $62.1 million, or 17.3 percent, during the three and nine months ended September 30, 2025, respectively, as compared to the same periods in 2024. The following section discusses the primary drivers for the increase in net income during the three and nine months ended September 30, 2025 as compared to the same periods in 2024.

Current wording

OG&E's net income decreased $13.1 million, or 18.5 percent, during the three months ended March 31, 2026, as compared to the same period in 2025. The following section discusses the primary drivers for the decrease in net income during the three months ended March 31, 2026 as compared to the same period in 2025.

Previous wording

Operating revenues increased $79.6 million, or 8.2 percent, and $309.5 million, or 13.9 percent, during the three and nine months ended September 30, 2025, respectively, primarily driven by the below factors.

Current wording

Operating revenues increased $4.9 million, or 0.7 percent, during the three months ended March 31, 2026, primarily driven by the below factors.

Previous wording

These expenses are generally recoverable from customers through regulatory mechanisms and are offset in Fuel, Purchased Power and Direct Transmission Expense in the statements of income. The primary drivers of the changes in fuel, purchased power and direct transmission expense during the periods are further detailed in the table below.

Current wording

These expenses are generally recoverable from customers through regulatory mechanisms and are offset in Fuel, Purchased Power and Direct Transmission Expense in the statements of income. The primary drivers of the changes in fuel, purchased power and direct transmission expense during the period are further detailed in the table below.

Previous wording

Fuel, purchased power and direct transmission expense for OG&E consists of fuel used in electric generation, purchased power and transmission related charges. As described above, the actual cost of fuel used in electric generation and certain purchased power costs are generally recoverable from OG&E's customers through fuel adjustment clauses. The fuel adjustment clauses are subject to periodic review by the OCC and the APSC. OG&E's fuel, purchased power and direct transmission expense increased $38.4 million, or 11.0 percent, and $197.4 million, or 25.4 percent, during the three and nine months ended September 30, 2025, respectively, primarily driven by the below factors.

Current wording

Fuel, purchased power and direct transmission expense for OG&E consists of fuel used in electric generation, purchased power and transmission related charges. As described above, the actual cost of fuel used in electric generation and certain purchased power costs are generally recoverable from OG&E's customers through fuel adjustment clauses. The fuel adjustment clauses are subject to periodic review by the OCC and the APSC. OG&E's fuel, purchased power and direct transmission expense increased $12.7 million, or 3.9 percent, during the three months ended March 31, 2026, primarily driven by the below factors.

Previous wording

Increased primarily due to higher fuel costs related to the generating assets utilized during the three and nine months ended September 30, 2025.

Current wording

Increased primarily due to higher fuel costs related to the generating assets utilized during the period.

Previous wording

Depreciation and amortization expense increased $2.7 million, or 1.9 percent, and $16.0 million, or 3.9 percent, during the three and nine months ended September 30, 2025, respectively, primarily due to additional assets being placed into service and increased amortization of certain regulatory assets, partially offset by deferrals of allowable depreciation and amortization expense of $2.8 million to a regulatory asset in accordance with SB 998, as further discussed in Note 1 within "Item 1. Financial Statements."

Current wording

Depreciation and amortization expense decreased $1.0 million, or 0.7 percent, during the three months ended March 31, 2026, primarily due to deferrals of allowable depreciation and amortization expense of $11.2 million to a regulatory asset in accordance with Oklahoma PISA, partially offset by additional assets being placed into service.

Previous wording

Net other income decreased $4.3 million, or 37.1 percent, and $5.2 million, or 18.3 percent, during the three and nine months ended September 30, 2025, respectively, primarily due to higher other net periodic benefit expense driven by changes to the level of pension expense included in base rates as a result of the most recent Oklahoma rate review. For the decrease during the nine months ended September 30, 2025, the higher other net periodic benefit cost was partially offset by increased interest income related to the carrying charge for the higher fuel under recovery balance.

Current wording

Net other income decreased $2.0 million, or 22.5 percent, during the three months ended March 31, 2026, primarily due to decreased interest income related to the carrying charge for the higher fuel under recovery balance in early 2025.

Previous wording

Changed primarily due to timing of power delivery and power generation projects.

Current wording

Changed primarily due to timing of power delivery projects and an increase in the cost of removals.

Previous wording

Changed primarily due to a decrease of senior notes issuances in 2025 compared to 2024 and the repayment of the Muskogee industrial authority bonds that matured in January 2025, partially offset by an increase in commercial paper borrowings.

Current wording

Changed primarily due to decreases in long-term revolver borrowings and short-term debt, partially offset by the repayment of the Muskogee industrial authority bonds that matured in January 2025.

Previous wording

Accounts Receivable and Accrued Unbilled Revenues increased $217.3 million, or 68.9 percent, primarily due to an increase in billings to OG&E's retail customers reflecting higher seasonal usage in September 2025 as compared to December 2024.

Current wording

Accounts Receivable and Accrued Unbilled Revenues decreased $51.3 million, or 12.1 percent, primarily due to a decrease in billings to OG&E's retail customers reflecting lower usage in early 2026 compared to late 2025.

Previous wording

Accrued taxes increased $38.9 million, or 66.1 percent, primarily resulting from the timing of payments for federal tax liabilities.

Current wording

Accrued Taxes decreased $20.2 million, or 38.1 percent, primarily resulting from the timing of payments for ad valorem taxes.

Previous wording

Fuel Clause Under Recoveries decreased $74.2 million, or 65.8 percent, primarily due to higher recoveries from OG&E retail customers as compared to the actual cost of fuel and purchased power.

Current wording

Fuel Clause Over Recoveries increased $28.2 million, primarily due to higher recoveries from OG&E retail customers as compared to the actual cost of fuel and purchased power.

Previous wording

OGE Energy's primary, material cash requirements are related to acquiring or constructing new facilities and replacing or expanding existing facilities at OG&E. Other working capital requirements are expected to be primarily related to maturing debt, operating lease obligations, fuel clause under recoveries and other general corporate purposes. Further, working capital requirements can be seasonal. OGE Energy generally meets its cash needs through a combination of cash generated from operations, short-term borrowings (through a combination of bank borrowings and commercial paper) and permanent financings. OGE Energy believes its cash flows from operations, existing borrowing capacity, and access to debt and equity capital markets, as needed, should be sufficient to satisfy material cash requirements over the short-term and long-term.

Current wording

OGE Energy's primary, material cash requirements are related to acquiring or constructing new facilities and replacing or expanding existing facilities at OG&E. Other working capital requirements include items such as maturing debt, operating lease obligations, fuel clause under recoveries and other general corporate purposes. Further, working capital requirements can be seasonal. OGE Energy generally meets its cash needs through a combination of cash generated from operations, short-term borrowings (through a combination of bank borrowings and commercial paper) and permanent financings. OGE Energy believes its cash flows from operations, existing borrowing capacity, and access to debt and equity capital markets, as needed, should be sufficient to satisfy material cash requirements over the short-term and long-term.

Previous wording

OGE Energy's estimates of capital expenditures, which represent base maintenance capital expenditures plus capital expenditures for known and committed projects, for the years 2025 through 2029 are presented in the following table. The capital investments are customer-focused and targeted to maintain and improve the safety, resiliency and reliability of OG&E's distribution and transmission grid and generation fleet, enhance the ability of OG&E's system to perform during extreme weather events and to serve OG&E's growing customer base.

Current wording

OGE Energy's estimates of capital expenditures for the years 2026 through 2030 are discussed in detail within "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations" in the Registrants'2025 Form 10-K, and OGE Energy's estimates have not changed significantly at this time. The capital investments are customer-focused and targeted to maintain and improve the safety, resiliency and reliability of OG&E's distribution and transmission grid and generation fleet, enhance the ability of OG&E's system to perform during extreme weather events and to serve OG&E's growing customer base. Additional capital expenditures beyond those identified in the Registrants'2025 Form 10-K, including additional incremental growth opportunities, will be evaluated based upon the requirements of OG&E's power supply, transmission and distribution operational teams and the expected resultant customer benefits.

Previous wording

Management expects that cash generated from operations, proceeds from the issuance of long- and short-term debt, proceeds from the sales of common stock to the public, including through OGE Energy's Automatic Dividend Reinvestment and Stock Purchase Plan, or other offerings will be adequate over the short-term and the long-term to meet anticipated cash needs and to fund future growth opportunities. OGE Energy utilizes short-term borrowings (through a combination of bank borrowings and commercial paper) to satisfy temporary working capital needs and as an interim source of financing capital expenditures until permanent financing is arranged.

Current wording

Management expects that cash generated from operations, proceeds from the issuance of long- and short-term debt, proceeds from the settlement of the FSAs, sales of common stock to the public, including through OGE Energy's Automatic Dividend Reinvestment and Stock Purchase Plan, or other offerings will be adequate over the short-term and the long-term to meet anticipated cash needs and to fund future growth opportunities. OGE Energy utilizes short-term borrowings (through a combination of bank borrowings and commercial paper) to satisfy temporary working capital needs and as an interim source of financing capital expenditures until permanent financing is arranged.

Previous wording

The following table presents information about OGE Energy's total short-term debt activity for the three and nine months ended September 30, 2025.

Current wording

The following table presents information about OGE Energy's total short-term debt activity for the three months ended March 31, 2026.

Previous wording

On April 1, 2025, OG&E issued $350.0 million of 5.80 percent senior notes due April 1, 2055. The proceeds from this issuance were added to OG&E's general funds and used for the repayment of short-term debt and borrowings under its revolving credit facility, and to fund OG&E's capital investment program and working capital needs.

Current wording

On April 1, 2026, OG&E issued $350.0 million of 5.90 percent senior notes due April 1, 2056. The proceeds from this issuance were added to OG&E's general funds and used for general corporate purposes, including repayment of short-term debt, repayment of borrowings under OG&E's revolving credit facility, and funding of OG&E's capital investment program and working capital needs.

Previous wording

On April 14, 2025, Moody's Investors Service revised their ratings outlook on both OGE Energy and OG&E from stable to negative. Moody's Investors Service indicated that the revised outlook reflects pressure related to OG&E's capital expenditure plan and higher debt levels at the holding company.

Current wording

On April 20, 2026, Moody's Investors Service revised their ratings outlook on both OGE Energy and OG&E to stable from negative. Moody's Investors Service indicated the stabilization of outlooks reflects an expectation that OGE Energy and OG&E will maintain adequate financial metrics over the next few years that are consistent with current rating levels.

Previous wording

In management's opinion, the areas where the most significant judgment is exercised include the determination of pension and postretirement plan assumptions, income taxes, contingency reserves, and regulatory assets and liabilities. The selection, application and disclosure of the critical accounting estimates have been discussed with the Audit Committee of OGE Energy's Board of Directors and are discussed in detail within "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations" in the Registrants'2024 Form 10-K.

Current wording

In management's opinion, the areas where the most significant judgment is exercised include the determination of pension and postretirement plan assumptions, income taxes, contingency reserves, and regulatory assets and liabilities. The selection, application and disclosure of the critical accounting estimates have been discussed with the Audit Committee of OGE Energy's Board of Directors and are discussed in detail within "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations" in the Registrants'2025 Form 10-K.

Previous wording

Changes in presidential administrations can result in uncertainty regarding policy or initiatives relating to activities that may affect the environment. On March 12, 2025, the EPA announced that it would begin reconsideration of numerous regulations, including several that apply to OG&E. The EPA has begun this process for certain regulations as described below and must adhere to the legal requirements for enacting, revising, repealing, or replacing agency regulations. Future developments, such as changes in existing laws, introduction of new laws or regulations, or the emergence of new facts or conditions, may result in significant costs for the Registrants.

Current wording

Changes in presidential administrations can result in uncertainty regarding policy or initiatives relating to activities that may affect the environment. In March 2025, the EPA announced that it would begin reconsideration of numerous regulations, including several that apply to OG&E. The EPA has begun this process for certain regulations as described below and must adhere to the legal requirements for enacting, revising, repealing, or replacing agency regulations. Future developments, such as changes in existing laws, introduction of new laws or regulations, or the emergence of new facts or conditions, may result in significant changes to anticipated costs for the Registrants.

Previous wording

In 2015, the EPA updated the ambient air standards for ozone. Although Oklahoma meets these standards, the Clean Air Act requires states to submit plans to the EPA to ensure their emissions do not affect other states. Oklahoma submitted its plan in 2018. However, in January 2023, the EPA disapproved the plans of 19 states, including Oklahoma. In response, the Oklahoma Attorney General, the ODEQ and OG&E filed petitions for review in March 2023. A stay on the EPA's disapproval was granted in July 2023. The timing of further action is currently unknown.

Current wording

In 2015, the EPA updated the ambient air standards for ozone. Although Oklahoma meets these standards, the Clean Air Act requires states to submit implementation plans to the EPA to ensure their emissions do not affect other states. Oklahoma submitted its SIP in 2018. However, in January 2023, the EPA disapproved the SIPs of 19 states, including Oklahoma. In response, the Oklahoma Attorney General, the ODEQ and OG&E filed petitions for review in March 2023. A stay on the EPA's disapproval was granted in July 2023. The timing of further action is currently unknown.

Previous wording

In a related matter, in April 2022, the EPA published a proposed FIP related to the "Good Neighbor" requirements intended to reduce interstate NOX emissions. OG&E commented on this proposed FIP in June 2022. By June 2023, the EPA finalized this plan for 23 states, including Oklahoma. This final Good Neighbor FIP would revise Oklahoma's NOX emissions budget for electric generating units, including OG&E's, starting in 2023. The emissions budget would decrease over time based on achievable reductions. OG&E estimated a 34.5 percent reduction by 2026 from 2023 levels and a 50 percent reduction by 2027 from 2021 levels. In October 2023, several petitioners sought a stay of the final FIP from the U.S. Supreme Court, pending review of the challenges in the U.S. Court of Appeals for the District of Columbia. The U.S. Supreme Court granted the stay in June 2024. The EPA requested a delay in the case in February 2025, which was denied. In March 2025, the EPA sought to reconsider the rule without vacating it. The D.C. Circuit Court agreed to hold the case in abeyance in April 2025, requiring status reports every 90 days. The timing of further action is unknown.

Current wording

23 states, including Oklahoma. This final Good Neighbor FIP would revise Oklahoma's NOx emissions budget for electric generating units, including OG&E's, starting in 2023. The emissions budget would decrease over time based on achievable reductions. OG&E estimated a 34.5 percent reduction by 2026 from 2023 levels and a 50 percent reduction by 2027 from 2021 levels. Following the FIP issuance, OG&E has been considering options to cut emissions at its generating units, including buying emission allowances, installing selective catalytic reduction systems, switching coal units to gas, or retiring and replacing capacity. OG&E submitted its final 2024 IRP to the OCC and APSC in March 2024, which evaluates various compliance options related to the EPA's Good Neighbor FIP. Due to the uncertainty surrounding the SIP disapproval and FIP implementation, OG&E cannot determine the exact cost of compliance. The costs depend on the litigation outcome, chosen control strategies, regulatory approvals, and project timelines. However, OG&E estimated in mid-2023 that compliance costs could range from $2.4 billion to $2.8 billion, including $100 million to $300 million over the first 12 to 18 months following the FIP's effectiveness. OG&E plans to seek recovery of necessary environmental expenditures but cannot guarantee approval or timely recovery of all such expenditures. In October 2023, several petitioners sought a stay of the final FIP from the U.S. Supreme Court, pending review of the challenges in the U.S. Court of Appeals for the District of Columbia. The U.S. Supreme Court granted the stay in June 2024. The EPA requested a delay in the case in February 2025, which was denied. In March 2025, the EPA sought to reconsider the rule without vacating it. The D.C. Circuit Court agreed to hold the case in abeyance in April 2025, requiring status reports every 90 days. The timing of further action is unknown.

Previous wording

On December 13, 2024, the EPA published in the Federal Register a proposed rule that would revise the new source performance standards regulating NOx and SO 2 emissions from new, modified, and reconstructed stationary combustion turbines. The EPA is proposing more stringent NOx emissions standards and to retain the existing SO 2 standards. OG&E participated with trade associations to submit comments on the Proposed Rule on April 15, 2025. It is unknown what potential material impacts, if any, there will be from any final action by the EPA.

Current wording

In December 2024, the EPA published in the Federal Register a proposed rule that would revise the new source performance standards regulating NOx and SO 2 emissions from new, modified, and reconstructed stationary combustion turbines. OG&E participated with trade associations to submit comments on the proposed rule in April 2025. In January 2026, the EPA published in the Federal Register its final rule establishing NOx emissions standards for several subcategories of stationary combustion turbines based on the size, rates of utilization, design efficiency, and fuel type of these turbines. The rule applies to affected sources constructed, modified, or reconstructed after the December 2024 publication date. As only future, currently unknown activities are affected by this regulation, it is unknown what potential material impacts, if any, there will be from this final action by EPA.

Previous wording

On February 7, 2024, the EPA issued a final rule resulting from its reconsideration of the primary (health-based) and secondary (welfare-based) NAAQS for PM, which were set in 2013 and which the EPA declined to revise in 2020. The final rule lowers the primary annual PM 2.5 NAAQS from 12.0 µg/m 3 to 9.0 µg/m 3 and retains the other PM standards at their current levels, including the 24-hour PM 2.5 NAAQS. The EPA will determine which areas of the country meet the standards, such as making initial attainment and nonattainment designations, no later than two years after new standards are issued. States must develop and submit attainment plans no later than 18 months after the EPA finalizes nonattainment designations.

Current wording

In February 2024, the EPA issued a final rule resulting from its reconsideration of the primary (health-based) and secondary (welfare-based) NAAQS for PM, which were set in 2013 and which the EPA declined to revise in 2020. The final rule lowers the primary annual PM 2.5 NAAQS from 12.0 µg/m 3 to 9.0 µg/m 3 and retains the other PM standards at their current levels, including the 24-hour PM 2.5 NAAQS. The EPA will determine which areas of the country meet the standards, such as making initial attainment and nonattainment designations, no later than two years after new standards are issued. States must develop and submit attainment plans no later than 18 months after the EPA finalizes nonattainment designations.

Previous wording

The final rule was published in the Federal Register on March 6, 2024. Litigation on the final rule is proceeding in the D.C. Circuit. A coalition of 24 states, including Oklahoma, filed challenges to the final rule, and a separate coalition of states and other stakeholders filed to intervene in these challenges on behalf of the EPA. A coalition of 22 state governors separately requested the EPA to pause implementation of the final rule.

Current wording

Litigation on the final rule is proceeding in the D.C. Circuit. A coalition of 24 states, including Oklahoma, filed challenges to the final rule, and a separate coalition of states and other stakeholders filed to intervene in these challenges on behalf of the EPA. A coalition of 22 state governors separately requested the EPA to pause implementation of the final rule.

Previous wording

In July 2020, the ODEQ notified OG&E that the Horseshoe Lake generating units would be included in Oklahoma's second Regional Haze implementation period evaluation of visibility impairment impacts to the Wichita Mountains. OG&E submitted an analysis of all potential control measures for NOx on these units to the ODEQ. The ODEQ submitted a revised SIP to the EPA on August 12, 2022. On June 28, 2024, the EPA entered a consent decree that requires the EPA to propose action on the Oklahoma SIP no later than December 31, 2025, and take final action no later than December 31, 2026. It is unknown at this time what the outcome, or any potential material impacts, if any, will be from the evaluations by OG&E, the ODEQ and the EPA.

Current wording

In July 2020, the ODEQ notified OG&E that the Horseshoe Lake generating units that were in-service at the time would be included in Oklahoma's second Regional Haze implementation period evaluation of visibility impairment impacts to the Wichita Mountains. OG&E submitted an analysis of all potential control measures for NOx on these units to the ODEQ. The ODEQ submitted a revised SIP to the EPA in August 2022. In February 2026, the EPA proposed to approve the Oklahoma SIP revision, and a 2024 consent decree requires the EPA to take final action no later than December 31, 2026. It is unknown at this time what the outcome, or any potential material impacts, if any, will be from the evaluations by OG&E, the ODEQ and the EPA.

Previous wording

On April 25, 2024, the EPA released the final revised Mercury and Air Toxics Standards regulation with a compliance date in July 2027. A coalition of states, including Oklahoma, challenged this rule in the D.C. Circuit Court and sought a stay, which was denied. This coalition of states then filed an emergency stay application with the U.S. Supreme Court, which was also denied. On April 14, 2025, the EPA extended the compliance deadline to July 8, 2029. On June 17, 2025, the EPA proposed to repeal the revised Mercury and Air Toxics Standards, which would remove the revised emission limit and monitoring requirements. The potential material impacts, if any, of further actions by the EPA or final action by the D.C. Circuit Court are currently unknown.

Current wording

In April 2024, the EPA released the final revised Mercury and Air Toxics Standards regulation with a compliance date in July 2027. A coalition of states, including Oklahoma, challenged this rule in the D.C. Circuit Court and sought a stay, which was denied. This coalition of states then filed an emergency stay application with the U.S. Supreme Court, which was also denied. In April 2025, the EPA extended the compliance deadline to July 8, 2029. In June 2025, the EPA proposed to repeal the revised Mercury and Air Toxics Standards; the repeal was finalized in February 2026, removing the emission limit and monitoring requirements revised in 2024. In March 2026, the repeal was challenged in the D.C. Circuit Court. The potential material impacts, if any, of further actions by the EPA or final action by the D.C. Circuit Court are currently unknown.

Previous wording

On May 9, 2024, the EPA issued final rules for emission guidelines under Section 111(d) for existing fossil fuel-fired steam units and revised standards under Section 111(b) for new gas turbines. Under the rules, existing coal units must use carbon capture for 90 percent of emissions by 2032 if they plan to operate beyond 2039. If they plan to operate until 2039, they must co-fire with natural gas at 40 percent by 2030. Coal plants retiring by 2032 are exempt. Compliance decisions must be submitted to the state by May 2026.

Current wording

In May 2024, the EPA issued final rules establishing (i) emission guidelines under Section 111(d) of the Clean Air Act for existing fossil fuel-fired steam generating units and (ii) revised standards of performance under Section 111(b) for new natural gas-fired combustion turbines. Under these rules, existing coal-fired units that intend to operate beyond 2039 must achieve 90 percent carbon capture by 2032. Units that plan to operate until 2039 must co-fire with natural gas at 40 percent by 2030. Units that retire by 2032 are exempt from these requirements.

Previous wording

OG&E’s existing natural gas-fired boilers meet the new requirements, so no additional steps beyond reporting are needed. New natural gas-fired turbines commencing construction after May 23, 2023, would be required to use capacity factor thresholds to differentiate among new units establishing three subcategories: baseload, intermediate load, and low load. All three categories are subject to efficiency standards. Baseload units, those with a capacity factor greater than 40 percent, are also subject to a phase two requirement based on 90 percent capture of CO 2 with a compliance deadline of January 1, 2032.

Current wording

OG&E’s existing natural gas-fired boilers satisfy the new standards and therefore require no additional compliance measures other than reporting. For new natural gas-fired combustion turbines commencing construction after May 23, 2023, the 2024 GHG rules establish three subcategories—baseload, intermediate-load, and low-load—based on capacity factor thresholds, all of which are subject to efficiency requirements. Baseload units, defined as units with capacity factors greater than 40 percent, are also required to achieve 90 percent CO₂ capture by January 1, 2032.

Previous wording

Significant litigation is ongoing, including a challenge by OG&E and a multi-state challenge joined by Oklahoma. On May 24, 2024, several petitioners, including OG&E, filed motions to stay the rule in the D.C. Circuit, but all stay requests were denied on July 19, 2024. OG&E and others appealed this denial to the U.S. Supreme Court, which also denied the stay request on October 16, 2024. In February 2025, the D.C. Circuit, at the request of the EPA, placed the case in abeyance for 60 days. The EPA later requested to continue holding the case in abeyance while reconsidering the rule, which was also granted. On June 17, 2025, the EPA proposed to repeal the 2024 greenhouse gas rules for both existing and new units. The EPA also included an alternative proposal to repeal the rule for existing units in its entirety and the future carbon capture and sequestration requirements for new combustion turbines only. OG&E submitted comments and participated with trade associations to submit comments on the proposed rule to the EPA on August 6, 2025. The outcome of the litigation or proposed repeal of the greenhouse gases regulations is unknown, but the 2024 regulations are currently not stayed and future compliance timelines are in effect. OG&E continues to plan for compliance and, if the new emission standards and guidelines are implemented, compliance costs could be significant. Relatedly, on August 1, 2025, the EPA published a proposed rule to rescind the EPA's 2009 determination that greenhouse gas emissions cause or contribute to the endangerment of public health and welfare (the “2009 Endangerment Finding”). While the rescission of the 2009 Endangerment Finding would have no direct effect on the 2024 greenhouse gas rules for power plants or the pending proposed reconsideration, the rationale underlying such a rescission could impact the legal arguments raised in the ongoing litigation challenging the EPA’s 2024 greenhouse gas rules or any future litigation challenging the EPA’s potential repeal of the 2024 rules. OG&E continues to monitor these developments and plan for compliance with standards currently in effect.

Current wording

In June 2025, the EPA proposed to repeal the 2024 GHG rules for both existing and new units or, alternatively, to repeal the 2024 GHG rules for existing units and rescind the carbon capture requirements applicable to new combustion turbines. OG&E submitted comments on the 2025 proposed rules individually and through trade associations. Although the EPA has initiated reconsideration and proposed repeal, the 2024 power sector GHG rules have not been stayed, and future compliance timelines remain in effect. If the new emission standards and guidelines are implemented, compliance costs could be significant. OG&E continues to monitor these developments and plan for compliance with 2024 GHG rules standards currently in effect.

Previous wording

During 2024, approximately 95 percent of the ash from OG&E's River Valley, Muskogee and Sooner facilities was recovered and reused off-site in various ways, including soil stabilization, landfill cover, road base construction and cement and concrete production. Reusing fly ash reduces the need to manufacture cement resulting in reductions in greenhouse gas emissions from cement and concrete production. Based on estimates from the American Coal Ash Association, OG&E fly ash reuse helped avoid over approximately 4 million tons of CO 2 emissions in the last 16 years.

Current wording

Ash from OG&E's River Valley, Muskogee and Sooner facilities is recovered and reused off-site in various ways, including soil stabilization, landfill cover, road base construction and cement and concrete production. Reusing fly ash reduces the need to manufacture cement resulting in reductions in greenhouse gas emissions from cement and concrete production.

Previous wording

In 2015, the EPA issued a final rule addressing the effluent limitation guidelines for power plants under the Federal Clean Water Act. The final rule establishes technology- and performance-based standards that may apply to discharges of six waste streams including bottom ash transport water. On April 25, 2024, the EPA released a supplemental effluent limitations guidelines rule. OG&E has completed installation of dry bottom ash handling technology at an affected facility and is evaluating options at another affected facility to comply with the final rule. On October 2, 2025, the EPA released a proposed rule that would extend the December 31, 2029 compliance date to December 31, 2034.

Current wording

In 2015, the EPA issued a final rule addressing the effluent limitation guidelines for power plants under the Federal Clean Water Act. The final rule establishes technology- and performance-based standards that may apply to discharges of six waste streams including bottom ash transport water. In April 2024, the EPA released a supplemental effluent limitations guidelines rule. OG&E's installation of dry bottom ash handling technology at an affected facility complies with the 2024 rule requiring facilities to cease discharging bottom ash transport water. OG&E is evaluating compliance options at another affected facility, and in December 2025, the EPA published a final rule revising the deadline to cease bottom ash transport water discharge to December 31, 2034.

Previous wording

Since the purchase of the Redbud facility in 2008, OG&E has made investments in the infrastructure that have led to OG&E's average use of approximately 2.4 billion gallons per year of treated municipal effluent for cooling water at Redbud and McClain. This use of treated municipal effluent offsets the need for fresh water as cooling water, making fresh water available for other beneficial uses like drinking water, irrigation and recreation.

Current wording

OG&E has made investments in its infrastructure at Redbud and McClain that have led to OG&E's use of treated municipal effluent for cooling water at each plant, which offsets the need for fresh water as cooling water, making fresh water available for other beneficial uses like drinking water, irrigation and recreation.