OGE ENERGY CORP.

COMBINED NOTES TO THE CONDENSED FINANCIAL STATEMENTS

Index of Combined Notes to Condensed Financial Statements

The Combined Notes to the Condensed Financial Statements are a combined presentation for OGE Energy and OG&E. The following table indicates the Registrant(s) to which each Note applies.

1. Summary of Significant Accounting Policies

Organization

OGE Energy is a holding company whose primary investment provides electricity in Oklahoma and western Arkansas. OGE Energy's electric company operations are conducted through its wholly-owned subsidiary, OG&E, which generates, transmits, distributes and sells electric energy in Oklahoma and western Arkansas and are reported through OGE Energy's electric company business segment. OG&E's rates are subject to regulation by the OCC, the APSC and the FERC. OG&E was incorporated in 1902 under the laws of the Oklahoma Territory and is the largest electric company in Oklahoma, with a franchised service territory that includes Fort Smith, Arkansas and the surrounding communities. OG&E sold its retail natural gas business in 1928 and is no longer engaged in the natural gas distribution business.

The accounts of OGE Energy and its wholly-owned subsidiaries, including OG&E, are included in OGE Energy's condensed consolidated financial statements. All intercompany transactions and balances are eliminated in such consolidation.

Basis of Presentation

The condensed financial statements included herein have been prepared by the Registrants, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations; however, the Registrants believe that the disclosures are adequate to prevent the information presented from being misleading.

In the opinion of management, all adjustments necessary to fairly present the financial position of the Registrants at March 31, 2026 and December 31, 2025, the results of the Registrants' operations for the three months ended March 31, 2026 and 2025 and the Registrants' cash flows for the three months ended March 31, 2026 and 2025 have been included and are of a normal, recurring nature except as otherwise disclosed. Management also has evaluated the impact of events occurring after March 31, 2026 up to the date of issuance of these condensed financial statements, and these statements contain all necessary adjustments and disclosures resulting from that evaluation.

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 condensed financial statements and notes thereto should be read in conjunction with the audited financial statements and notes thereto included in the Registrants'2025 Form 10-K.

Accounting Records

The accounting records of OG&E are maintained in accordance with the Uniform System of Accounts prescribed by the FERC and adopted by the OCC and the APSC. Additionally, OG&E, as a regulated electric company, is subject to accounting principles for certain types of rate-regulated activities, which provide that certain incurred costs that would otherwise be charged to expense can be deferred as regulatory assets, based on the expected recovery from customers in future rates. Likewise, certain actual or anticipated credits that would otherwise reduce expense can be deferred as regulatory liabilities, based on the expected flowback to customers in future rates. Management's expected recovery of deferred costs and flowback of deferred credits generally results from specific decisions by regulators granting such ratemaking treatment.

OG&E records certain incurred costs and obligations as regulatory assets or liabilities if, based on regulatory orders or other available evidence, it is probable that the costs or obligations will be included in amounts allowable for recovery or refund in future rates. The following table presents a summary of OG&E's regulatory assets and liabilities.

(A)

Included in Other Current Assets in the condensed balance sheets.

(B)

Included in Other Current Liabilities in the condensed balance sheets.

Management continuously monitors the future recoverability of regulatory assets. When in management's judgment future recovery becomes impaired, the amount of the regulatory asset is adjusted, as appropriate. If OG&E were required to discontinue the applicationof accounting principles for certain types of rate-regulated activities for some or all of its operations, it could result in writing off the related regulatory assets or liabilities, which could have significant financial effects.

Allowance for Uncollectible Accounts Receivable

Customer balances are generally written off if not collected within six months after the final billing date. The allowance for uncollectible accounts receivable for OG&E is generally calculated by multiplying the last six months of electric revenue by the provision rate, which is based on a historical average of actual balances written off and is adjusted for current conditions and supportable forecasts as necessary. To the extent the historical collection rates, when incorporating forecasted conditions, are not representative of future collections, there could be an effect on the amount of uncollectible expense recognized. Also, a portion of the uncollectible provision related to fuel within the Oklahoma jurisdiction is being recovered through the fuel adjustment clause. The allowance for uncollectible accounts receivable is a reduction to Accounts Receivable in the condensed balance sheets and is included in Other Operation and Maintenance Expense in the condensed statements of income.

New business customers are required to provide a security deposit in the form of cash, bond or irrevocable letter of credit that is refunded when the account is closed or when certain requirements are met. New residential customers whose outside credit scores indicate an elevated risk are required to provide a security deposit that is refunded based on customer protection rules defined by the OCC and the APSC. The payment behavior of all existing customers is continuously monitored, and, if the payment behavior indicates sufficient risk within the meaning of the applicable utility regulation, customers will be required to provide a security deposit.

Accumulated Other Comprehensive Income (Loss)

The following tables present changes in the components of accumulated other comprehensive income (loss) attributable to OGE Energy during thethree months ended March 31, 2026 and 2025. All amounts below are presented net of tax.

The following table presents significant amounts reclassified out of accumulated other comprehensive income (loss) attributable to OGE Energy by the respective line items in net income during thethree months ended March 31, 2026 and 2025.

(A)

These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost (see Note 10 for additional information).

2. Accounting Pronouncements

In November 2024, the Financial Accounting Standards Board issued ASU 2024-03, "Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures." The amendments in this update improve financial reporting by requiring disclosure of additional information about specific expense categories in the notes to financial statements on an annual and interim basis. This standard is effective for fiscal years beginning after December 15, 2026 and interim periods beginning after December 15, 2027. Early adoption is permitted. The Registrants are evaluating the impact of this standard and do not believe it will have a material impact on their financial statement disclosures.

In September 2025, the Financial Accounting Standards Board issued ASU 2025-06, "Intangibles - Goodwill and Other - Internal-Use Software." The targeted improvements in this update aim to better align current software development processes when considering capitalization of internal-use software costs. This standard is effective for fiscal years beginning after December 15, 2027 and interim periods within that period. Early adoption is permitted. The Registrants are evaluating the impact of this standard on their financial statements.

The Registrants believe that other recently adopted and recently issued accounting standards that are not yet effective do not appear to have a material impact on the Registrants' financial position, results of operations or cash flows upon adoption.

3. Revenue Recognition

The following table presents OG&E's revenues from contracts with customers disaggregated by customer classification. OG&E's operating revenues disaggregated by customer classification can be found in "OG&E (Electric Company) Results of Operations" within "Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations."

4. Fair Value Measurements

The classification of the Registrants' fair value measurements requires judgment regarding the degree to which market data is observable or corroborated by observable market data. GAAP establishes a fair value hierarchy that prioritizes the inputs used to measure fair value based on observable and unobservable data. The hierarchy categorizes the inputs into three levels, with the highest priority given to quoted prices in active markets for identical unrestricted assets or liabilities (Level 1) and the lowest priority given to unobservable inputs (Level 3). Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The three levels defined in the fair value hierarchy are as follows:

Level 1 inputs are quoted prices in active markets for identical unrestricted assets or liabilities that are accessible at the measurement date.

Level 2 inputs are inputs other than quoted prices in active markets included within Level 1 that are either directly or indirectly observable at the reporting date for the asset or liability for substantially the full term of the asset or liability. Level 2 inputs include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active.

Level 3 inputs are prices or valuation techniques for the asset or liability that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity). Unobservable inputs reflect the reporting entity's own assumptions about the assumptions that market participants would use in pricing the asset or liability (including assumptions about risk).

The Registrants hadno financial instruments measured at fair value on a recurring basis at March 31, 2026 and December 31, 2025. The following table presents the carrying amount and fair value of the Registrants' financial instruments at March 31, 2026 and December 31, 2025, as well as the classification level within the fair value hierarchy.

5. Stock-Based Compensation

The following table presents the Registrants' pre-tax compensation expense and related income tax benefit for thethree months ended March 31, 2026 and 2025 related to performance units and restricted stock units for the Registrants' employees.

During the three months ended March 31, 2026, OGE Energy issued 168,659 shares of new common stock pursuant to OGE Energy's Stock Incentive Plan to satisfy payouts of earned performance units and restricted stock unit grants to the Registrants' employees.

During the three months ended March 31, 2026, OGE Energy granted 220,459 performance units (based on total shareholder return over a three-year period) and 129,233 restricted stock units (primarily with a three-year cliff vesting period) to the Registrants' employees at $56.63 and $46.45 fair value per share, respectively.

6. Income Taxes

OGE Energy files consolidated income tax returns in the U.S. federal jurisdiction and various state jurisdictions. OG&E is a part of the consolidated income tax return of OGE Energy. With few exceptions, the Registrants are no longer subject to U.S. federal tax or state and local examinations by tax authorities for years prior to 2022. Income taxes are generally allocated to each company in the affiliated group, including OG&E, based on its stand-alone taxable income or loss. Federal investment tax credits previously claimed on electric utility property have been deferred and will be amortized to income over the life of the related property. Oklahoma investment tax credits are also earned on investments at electric generating facilities which further reduce OG&E's effective tax rate.

7. Common Equity

Automatic Dividend Reinvestment and Stock Purchase Plan

OGE Energy issued 65,207 new shares of common stock under its Automatic Dividend Reinvestment and Stock Purchase Plan during thethree months ended March 31, 2026 and received proceeds of $2.8 million. OGE Energy may, from time to time, issue additional shares under its Automatic Dividend Reinvestment and Stock Purchase Plan to fund capital requirements or working capital needs. As of March 31, 2026, there were 4,998,312 shares of unissued common stock reserved for issuance under OGE Energy's Automatic Dividend Reinvestment and Stock Purchase Plan.

Common Stock Public Offering and Forward Equity Sale Agreements

In November 2025, OGE Energy entered into FSAs in connection with a completed public offering of 9,226,744 shares of its common stock. The 4,613,372 shares that are subject to the FSAs provide for settlement on a settlement date or dates to be specified at OGE Energy’s discretion on or prior to May 27, 2027. The forward sale price was initially $41.71 per share and is subject to adjustment based on a floating interest rate factor equal to the overnight bank funding rate less a spread and less expected dividends on OGE Energy's common stock during the period the instruments are outstanding. The FSAs will be physically settled with common shares issued by OGE Energy, unless OGE Energy elects to settle the agreements in net cash or net shares, subject to certain conditions. On a settlement date or dates, if OGE Energy elects to physically settle the FSAs, OGE Energy will issue shares of common stock to the various counterparties at the then-applicable forward sale price and receive issuance proceeds at that time.

At March 31, 2026, OGE Energy could have settled the FSAs with physical delivery of 4,613,372 shares of common stock to the counterparties in exchange for cash of$192.4 million. The FSAs could have also been settled at March 31, 2026, with delivery of $18.3 million of cash or approximately 401,000 shares of common stock to the counterparties, if OGE Energy had elected to net cash or net share settle, respectively. The FSAs have been classified as an equity transaction; therefore, no gain or loss will be recognized within earnings due to subsequent changes in the fair value of the FSAs.

Prior to settlement, the potentially issuable shares pursuant to the FSAs will be reflected in OGE Energy's diluted earnings per share calculations using the treasury stock method. Under this method, the number of shares of OGE Energy's common stock used in calculating diluted earnings per share for a reporting period would be increased by the number of shares, if any, that would be issued upon physical settlement of the FSAs, less the number of shares that could be purchased by OGE Energy in the market with the proceeds received from issuance (based on the average market price during that reporting period). Share dilution occurs when the average market price of OGE Energy's stock during the reporting period is higher than the then-applicable forward sale price as of the end of the reporting period. As of March 31, 2026, approximately 401,000 incremental shares were included in the calculation of diluted earnings per share related to the securities under the FSAs.

Earnings Per Share

Basic earnings per share is calculated by dividing net income attributable to OGE Energy by the weighted-average number of OGE Energy's common shares outstanding during the period. In the calculation of diluted earnings per share, weighted-average shares outstanding are increased for additional shares that would be outstanding if potentially dilutive securities were converted to common stock. Potentially dilutive securities for OGE Energy consist of performance units and restricted stock units and shares under the FSAs, as further discussed above.

The following table presents the calculation of basic and diluted earnings per share for OGE Energy.

8. Long-Term Debt

At March 31, 2026, the Registrants were in compliance with all of their debt agreements.

OG&E Industrial Authority Bonds

OG&E has tax-exempt pollution control bonds with optional redemption provisions that allow the holders to request repayment of the bonds on any business day. The following table presents information about these bonds, which can be tendered at the option of the holder during the next 12 months.

All of these bonds are subject to an optional tender at the request of the holders, at 100 percent of the principal amount, together with accrued and unpaid interest to the date of purchase. The bond holders, on any business day, can request repayment of the bond by delivering an irrevocable notice to the tender agent stating the principal amount of the bond, payment instructions for the purchase price and the business day the bond is to be purchased. The repayment option may only be exercised by the holder of a bond for the principal amount. When a tender notice has been received by the trustee, a third-party remarketing agent for the bonds will attempt to remarket any bonds tendered for purchase. This process occurs once per week. Since the original issuance of these series of bonds in 1995 and 1997, the remarketing agent has successfully remarketed all tendered bonds. If the remarketing agent is unable to remarket any such bonds, OG&E is obligated to repurchase such unremarketed bonds. As OG&E has both the intent and ability to refinance the bonds on a long-term basis and such ability is supported by an ability to consummate the refinancing, the remarketing of bonds does not result in short-term debt classification in the condensed balance sheets. OG&E believes that it has sufficient liquidity to meet these obligations.

Issuance of Long-Term Debt

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.

9. Credit Facilities and Short-Term Debt

The Registrants borrow, as necessary, by the issuance of commercial paper and by borrowings under their revolving credit agreements. The following table presents information regarding the Registrants' revolving credit agreements at March 31, 2026.

(A)

Includes direct borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit at March 31, 2026. Typically, OGE Energy issues commercial paper to address consolidated operational activity, and OG&E will borrow from OGE Energy under the intercompany borrowing agreement as discussed below in footnote (E).

(B)

This bank facility is available to back up OGE Energy's commercial paper borrowings and to provide revolving credit borrowings. This bank facility can also be used as a letter of credit facility.

(C)

OGE Energy has a $120.0 million floating rate unsecured three-year credit agreement, of which $60.0 million is considered a revolving loan, which is included in the table above, and $60.0 million is considered a term loan. The credit agreement, under certain circumstances, may be increased to a maximum commitment limit of $155.0 millionand includes a maximum leverage ratioof 0.70 to 1.0. The other covenants under this credit agreement are substantially the same as OGE Energy's existing $550.0 million revolving credit agreement.

(D)

This bank facility is available to back up OG&E's commercial paper borrowings and to provide revolving credit borrowings. This bank facility can also be used as a letter of credit facility.

(E)

OG&E has an intercompany borrowing agreement with OGE Energy whereby OG&E has access to up to $450.0 million of OGE Energy's revolving credit amount. This agreement has a termination date of December 18, 2029. At March 31, 2026, there were $41.1 million in borrowings under this agreement.

(F)

Represents the weighted-average interest rate for the outstanding borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit.

OG&E must obtain regulatory approval from the FERC in order to borrow on a short-term basis. OG&E has the necessary regulatory approvals to incur up to $1.0 billion in short-term borrowings at any one time for a two-year period beginning January 1, 2025 and ending December 31, 2026.

10. Retirement Plans and Postretirement Benefit Plans

Net Periodic Benefit Cost

The following tables present the net periodic benefit cost components, before consideration of capitalized amounts, of OGE Energy's Pension Plan, Restoration of Retirement Income Plan and postretirement benefit plans that are included in the condensed financial statements. Service cost is presented within Other Operation and Maintenance Expense, and the remaining net periodic benefit cost components as listed in the following tables are presented within Other Net Periodic Benefit Expense in the statements of income. OG&E recovers specific amounts of pension and postretirement medical costs in rates approved in its Oklahoma rate reviews. In accordance with approved orders, OG&E defers the difference between actual pension and postretirement medical expenses and the amount approved in its last Oklahoma rate review as a regulatory asset or regulatory liability. These amounts have been recorded in the Pension tracker in the regulatory assets and liabilities table in Note 1 and within Other Net Periodic Benefit Expense in the statements of income.

(A)Unamortized prior service cost is amortized on a straight-line basis over the average remaining service period to the first eligibility age of participants who are expected to receive a benefit and are active at the date of the plan amendment.

In addition to the net periodic benefit cost amounts recognized, as presented in the tables above, for the Pension and Restoration of Retirement Income Plans during the three months ended March 31, 2026 and 2025, the Registrants recognized the following:

(A)

Included in the pension regulatory asset in each jurisdiction, as indicated in the regulatory assets and liabilities table in Note 1.

In addition to the net periodic benefit cost amounts recognized, as presented in the table above, for the postretirement benefit plans during the three months ended March 31, 2026 and 2025, the Registrants recognized the following:

(A)

Included in the pension regulatory asset, as indicated in the regulatory assets and liabilities table in Note 1.

The following table presents the amount of net periodic benefit cost capitalized and attributable to each of the Registrants for OGE Energy's Pension Plan and postretirement benefit plans for thethree months ended March 31, 2026 and 2025.

Pension Plan Funding

In March 2026, OGE Energy made a $5.0 million contribution to its Pension Plan related to OG&E employees and expects to make an additional contribution of $10.0 million to the Pension Plan in 2026. The Registrants could be required to make additional contributions if the value of its pension trust and postretirement benefit plan trust assets are adversely impacted by a major market disruption in the future.

11. Report of Business Segments

OGE Energy reports its operations primarily through asingle segment, captioned "electric company," which is engaged in the generation, transmission, distribution and sale of electric energy. The "other operations" caption primarily includes the operations of the holding company and other energy-related investments. Intersegment revenues are recorded at prices comparable to those of unaffiliated customers and are affected by regulatory considerations. The Registrants' chief operating decision maker uses net income as a measure of reportable segment profit or loss to make operating decisions, allocate resources, and assess performance. The following tables, which include significant segment expenses, present the results of OGE Energy's business segments for thethree months ended March 31, 2026 and 2025.

12. Commitments and Contingencies

Except as set forth below, in Note 13 and under "Environmental Laws and Regulations" in Item 2 of Part I and in Item 1 of Part II of this Form 10-Q, the circumstances set forth in Notes 13 and 14 to the financial statements included in the Registrants'2025 Form 10-K appropriately represent, in all material respects, the current status of the Registrants' material commitments and contingent liabilities.

Environmental Laws and Regulations

The activities of OG&E are subject to numerous stringent and complex federal, state and local laws and regulations governing environmental protection. These laws and regulations can change, restrict or otherwise impact the Registrants' business activities in many ways, including the handling or disposal of waste material, planning for future construction activities to avoid or mitigate harm to threatened or endangered species and requiring the installation and operation of emissions or pollution control equipment. Failure to comply with these laws and regulations could result in the assessment of administrative, civil and criminal penalties, the imposition of remedial requirements and the issuance of orders enjoining future operations. Management believes that all of the Registrants' operations are in substantial compliance with current federal, state and local environmental standards.

Environmental regulation can increase the cost of planning, design, initial installation and operation of OG&E's facilities. Management continues to evaluate its compliance with existing and proposed environmental legislation and regulations and implement appropriate environmental programs in a competitive market.

Other

In the normal course of business, the Registrants are confronted with issues or events that may result in a contingent liability. These generally relate to lawsuits or claims made by third parties, including governmental agencies. When appropriate, management consults with legal counsel and other experts to assess the claim. If, in management's opinion, the Registrants have incurred a probable loss as set forth by GAAP, an estimate is made of the loss, and the appropriate accounting entries are reflected in the condensed financial statements. If the assessment indicates that a potential loss is not probable but reasonably possible, the nature of the contingent matter, together with an estimate of the range of possible loss if determinable and material, would be disclosed. At the present time, based on currently available information, except as disclosed below, the Registrants believe that any reasonably possible losses in excess of accrued amounts arising out of pending or threatened lawsuits or claims would not be quantitatively material to their condensed financial statements and would not have a material adverse effect on their financial position, results of operations or cash flows.

In 2023, OG&E was named, along with its contractor, as a defendant in a lawsuit filed by an apartment owner and its insurance companies seeking in excess of $60.0 million in damages related to a fire at an apartment building under construction in Oklahoma City. Several additional defendants have also been named. OG&E disputes the claims in the lawsuit and intends to vigorously defend this action. If OG&E is ultimately deemed liable for damages in connection with this incident, OG&E believes its existing insurance policies will cover its costs, in excess of a required retention (the amount of which is not material), to satisfy any liability it may have. Due to the uncertain nature of this litigation, the outcome cannot be predicted, and OG&E is unable to provide a range of possible loss in this matter.

13. Rate Matters and Regulation

Except as disclosed below, the circumstances set forth in Note 14 to the financial statements included in the Registrants'2025 Form 10-K appropriately represent, in all material respects, the current status of the Registrants' regulatory matters.

Completed Regulatory Matters

Integrated Resource Plans

In 2025, OG&E issued its 2025 IRP to the OCC and APSC. The 2025 IRP was intended to address updated planning assumptions from OG&E’s 2024 IRP and present OG&E’s current capacity needs in light of the SPP’s planning reserve margin requirements for both summer and winter seasons as well as the SPP’s revised resource accreditation methodologies and updated load projections. The 2025 IRP identified capacity needs of 1,647 MWs by 2030. OG&E has executed contracts for nearly 1,000 MWs of generation as a result of the 2024 request for proposal process, and regulatory approvals are currently being pursued, as further discussed below. Further, in January 2026, OG&E issued additional requests for proposals for resources to meet projected capacity needs while maintaining affordability and reliability for OG&E's customers. On April 23, 2026, OG&E issued its final 2026 IRP to the OCC and APSC, which is intended to address OG&E's updated load forecast as well as updated SPP Resource Adequacy policies. The 2026 IRP identifies capacity needs of 1,922 MWs by the 2031/2032 winter season, which is inclusive of approximately 800 MWs of capacity needs driven by changes in the SPP Resource Adequacy policies. During the second quarter of 2026, OG&E expects to file long-term special contracts with the OCC to serve multiple Google data centers. The electric service expected to be provided pursuant to the special contracts is consistent with the assumptions in both the 2025 and 2026 IRPs. OG&E intends to evaluate incremental capacity needs through future IRPs and to continue to seek capacity additions, as needed.

APSC Proceedings

2025 Arkansas Act 373 Tariff Filing

In December 2025, OG&E filed an application for approval of an Act 373 tariff to recover return on CWIP and revenue requirement for Horseshoe Lake and Tinker generation facilities. Recovery under the Act 373 tariff is dependent on a finding of eligibility for the Horseshoe Lake Units 11 and 12 and Tinker generation facilities in the prudence case disclosed below. On April 27, 2026, the APSC issued an order approving OG&E's Act 373 tariff.

Pending Regulatory Matters

Various proceedings pending before state or federal regulatory agencies are described below. Unless stated otherwise, the Registrants cannot predict when the regulatory agency will act or what action the regulatory agency will take. The Registrants' financial results are dependent in part on timely and constructive decisions by the regulatory agencies that set OG&E's rates.

SPP Proceedings

Demand Response Accreditation

The SPP has been evaluating demand response accreditation for several years, and a proposal has evolved that would treat demand resource accreditation on a performance-based approach. This approach requires demand response resources to be market registered and dispatched based on SPP market protocols or be reliability registered and dispatched during conservative operations or energy emergency alerts within the SPP. Alternatively, demand response programs that are built into a LRE’s forecast, known as load modifiers, can be used to reduce the load and resources needed to satisfy the entity’s planning reserve margin but would include an after-the-fact look at whether the LRE’s peak forecast was below the actuals in a given year. If under forecasted, a LRE would have to pay a deficiency payment for not providing enough resources to satisfy its planning reserve margin and actual peak load. At their February 2026 meetings, both the SPP Regional State Committee and the SPP Board of Directors adopted policies to include the 2027 implementation of a LRE’s load modifier cap and full implementation in 2028. These policies are subject to FERC review and approval prior to implementation.

Seminole to Shreveport Transmission Line

At the end of 2025, the SPP Board of Directors adopted their 2025 Integrated Transmission Plan. This plan included a new 765kV transmission line running from Konawa, Oklahoma to Shreveport, Louisiana. OG&E will construct and own a significant portion of the line. The project is pending OG&E's receipt and acceptance of a notice to construct, which is expected later this year.

APSC Proceedings

Arkansas Prudence of Horseshoe Lake and Tinker Generation Facilities

In December 2024, pursuant to orders in the generation construction notice filings, OG&E filed an application requesting a determination of prudence of action and initial contract costs for the generating units being constructed at Horseshoe Lake (Units 11 and 12) and Tinker Air Force Base. In May 2025, intervenors, including the Attorney General, filed direct testimony and APSC staff recommended a finding of prudence of action and initial contract costs for both projects. The Attorney General recommended approval of the Horseshoe Lake project but raised concerns regarding certain elements of the Tinker Air Force Base project. In May 2025, OG&E filed a supplemental application to serve as notice to the APSC of OG&E’s intent to recover the costs of these projects through a rider under the newly enacted Act 373. In June 2025, OG&E filed rebuttal testimony to address concerns raised by the Attorney General in direct testimony. OG&E entered into a settlement agreement with APSC Staff in August 2025 that agreed the Horseshoe Lake and Tinker combustion turbines were prudent and that OG&E satisfied part of the eligibility criteria for recovery of these costs through a Strategic Investment Rider. The Arkansas Attorney General opposes the part of the settlement relating to eligibility for a Strategic Investment Rider. In August 2025, the APSC issued an order seeking additional testimony that responds to several questions related to the eligibility of the Strategic Investment Rider for out of state projects. In September 2025, OG&E and APSC Staff filed responsive supplemental testimony. OG&E is awaiting a final order from the APSC.

2025 Arkansas Preapproval Case

In July 2025, OG&E filed an application requesting several approvals from the APSC relating to three capacity projects arising from the 2024 request for proposals for generating capacity: (i) the Black Kettle Battery Storage capacity purchase agreement; (ii) the Kiamichi natural gas capacity purchase agreement; and (iii) construction of two additional combustion turbines at the Horseshoe Lake generating facility (Units 13 and 14). OG&E sought authority to begin construction of the Horseshoe Lake units, a prudency determination of those new Horseshoe Lake units, authorization to enter into the Black Kettle Battery Storage capacity purchase agreement and other findings needed under Arkansas law, including eligibility to recover costs of the new Horseshoe Lake units through a rider under the newly enacted Act 373. In November 2025, OG&E and the APSC staff filed a settlement agreement approving OG&E’s application with some additional reporting requirements and allowing an additional return on the Black Kettle Battery Storage capacity purchase agreement at the 20-year U.S. treasury rate. In December 2025, the Attorney General filed testimony in opposition to the settlement. In January 2026, the APSC issued an order denying the settlement agreement and denying preapproval of Horseshoe Lake Units 13 and 14 but approving the Black Kettle Battery Storage capacity purchase agreement. The APSC also found that OG&E did not need to seek approval of the Kiamichi natural gas capacity purchase agreement since the term is shorter than five years. In the order, the APSC stated OG&E could still seek a prudence determination and cost recovery of Horseshoe Lake Units 13 and 14 after they are placed into service. In February 2026, OG&E filed additional evidence pursuant to Arkansas law and requested that the APSC consider the additional evidence in finding that Horseshoe Lake Units 13 and 14 are reasonable, necessary and in the public interest. In March 2026, the APSC issued an order which again declined to grant prudence of Horseshoe Lake Units 13 and 14 but clarified that OG&E is authorized to begin construction and the APSC's previous order should not be construed to indicate prudence or imprudence. The APSC re-stated that OG&E may request approval for Horseshoe Lake Units 13 and 14 in a future rate case.

Arkansas Frontier Energy Storage Project Preapproval Filing

In February 2026, OG&E filed a preapproval case for the Frontier Energy Storage Project, which involves a purchase and sale agreement for a 300 MW battery storage facility in Oklahoma. The Frontier Energy Storage Project is the final project resulting from OG&E's 2024 request for proposals and subsequent negotiations. In this proceeding, OG&E seeks authorization to commence construction of the Frontier Energy Storage Project and to later acquire the facility pursuant to the purchase and sale agreement, a prudency determination for the project, and all other findings and approvals needed under Arkansas law. On April 1, 2026, the APSC Staff and the Attorney General filed direct testimony recommending approval of the Frontier Energy Storage Project, subject to certain conditions. OG&E's rebuttal testimony is due on May 1, 2026.

FERC Proceedings

Order for Sponsored Transmission Upgrades within SPP

Under Attachment Z2 of the SPP Open Access Transmission Tariff, costs of participant-funded, or "sponsored," transmission upgrades may be recovered from other SPP customers who benefit from the upgrade. The FERC approved a waiver of a time limitation in the SPP tariff to allow the SPP in 2016 to bill for the 2008 through 2015 period due to information system limitations that had delayed that billing. The SPP then both billed users and credited sponsors, including OG&E, for Z2 charges during the period. OG&E refunded most of the net credits to customers through its various rate riders that include SPP activity, with the remaining amounts retained by OG&E.

Net payers of Z2 credits contested the waiver, leading the FERC to reverse its decision, deny the waiver, and instruct the SPP to refund payments made for charges from 2008 to 2015. OG&E and other net creditors challenged this reversal. However, the FERC upheld its reversal, and in August 2021 and September 2024, the U.S. Court of Appeals upheld the FERC’s decision and denied relief to OG&E and the other creditors against SPP. All appellate options have now been exhausted.

The SPP has submitted a refund process to the FERC stating some issues need the FERC's clarification before refunds can proceed. OG&E and other parties have commented on the filings, and the matter remains pending before the FERC. The SPP has calculated that OG&E will need to refund approximately $14 million, net of amounts paid to other utilities for upgrades, plus interest. This would shift recovery of these upgrade credits to future periods. Of the $14 million, the Registrants would be impacted by $4 million in expense that initially benefited the Registrants in 2016, and OG&E customers would incur a net impact of $10 millionin expense through rider mechanismsor the FERC formula rate. As of March 31, 2026, the Registrants have reserved $14 million plus estimated interest for a potential refund.

Subsequent to the initiation of the disputes discussed above, the FERC approved an SPP proposal to eliminate Attachment Z2 revenue crediting and replace it with a different rate mechanism that would provide project sponsors, such as OG&E, the same level of recovery. This elimination of the Attachment Z2 revenue crediting would only impact OG&E and its recovery of any future upgrade costs that it may incur as a project sponsor after July 2020. All projects initiated prior to July 2020 remain eligible to receive revenue credits under Attachment Z2, which includes the $14 million related to the refunds discussed above.

OCC Proceedings

Oklahoma CWIP Filing

In December 2025, OG&E filed an application for CWIP treatment for Horseshoe Lake combustion turbines Units 13 and 14, as allowed by Oklahoma Senate Bill 998. A motion to dismiss the case was filed by the Oklahoma Industrial Energy Consumers, as well as the Public Utility Division Staff. OG&E filed a response as well as motions to move the case and all outstanding motions to be heard en banc. These motions were heard before the OCC in January 2026. In March 2026, the OCC issued an order dismissing the case, and on the same day, OG&E filed an appeal at the Oklahoma Supreme Court. On April 10, 2026, OG&E filed its opening brief, and response briefs are due by May 19, 2026.

Oklahoma Frontier Energy Storage Project Preapproval Filing

In December 2025, OG&E filed a preapproval case for the Frontier Energy Storage Project, which involves a purchase and sale agreement for a 300 MW battery storage facility in Oklahoma. The Frontier Energy Storage Project is the final project resulting from OG&E's 2024 request for proposals and subsequent negotiations. In January 2026, the Attorney General and Petroleum Alliance of Oklahoma filed a joint motion to dismiss the case based on an interpretation that a battery energy storage system is not an electric generation facility. In February 2026, OG&E filed a response in opposition to the joint motion to dismiss. On April 22, 2026, the Administrative Law Judge issued a report that recommended the OCC deny the joint motion to dismiss. A hearing on the merits is scheduled to begin on May 6, 2026.

Oklahoma 2025 Fuel Prudence

On April 1, 2026, the Public Utility Division Staff filed their application initiating the prudence review of the 2025 fuel adjustment clause. OG&E expects to file its minimum filing requirements and direct testimony no later than June 1, 2026, in accordance with OCC rules.