Description of the Plan	12 Months Ended
Dec. 31, 2025
EBP 002
EBP, Description of Plan [Line Items]
Description of the Plan	Description of the Plan The following brief description of the FirstEnergy Corp. Savings Plan (the Plan) is provided for general information purposes only. Participants should refer to the Plan documents for more complete information. General The Plan is a defined contribution plan and was established to provide a systematic savings program for eligible employees and to supplement such savings with employer contributions. The Plan is subject to the provisions of the Employee Retirement Income Security Act of 1974, as amended (ERISA), and the Internal Revenue Code of 1986, as amended (IRC). Administration FirstEnergy Corp. (FE) is the sponsor of the Plan. The FE Savings Plan Committee is the administrator of the Plan and has responsibility for the day-to-day administration of the Plan. Record keeping with respect to individual participant accounts is maintained by Fidelity Workplace Services, LLC. Plan assets are held in trust under an arrangement with Fidelity Management Trust Company. Participation Generally, all full-time and part-time employees of FE's subsidiaries and participating employees not represented by a collective bargaining union are eligible to participate in the Plan. Full-time and part-time employees represented by a labor union may participate to the extent permitted by their respective collective bargaining agreement. Unless otherwise provided in a collective bargaining agreement, new employees are automatically enrolled in the Plan with a deemed election to contribute, on a pre-tax basis, 6% of eligible earnings for each payroll period with automatic increases of 1% each April until the employee contribution rate reaches 10%. Automatic enrollment and annual increases can be changed by Plan participants at any time. Plan participants who do not make an affirmative election as to the investment of his or her contributions shall have his or her contributions invested in the age appropriate LifePath Portfolio Fund made available to all Plan participants. A LifePath Portfolio Fund is an investment alternative that provides a mixture of fixed income and equity investments that are matched to an individual’s age and assumed retirement date. Contributions Subject to IRC limitations, the Plan allows each participant to contribute 1% to 75% (unless otherwise provided by a collective bargaining agreement) of their eligible earnings to the Plan through payroll deductions. Participant contributions may be made as before-tax, after-tax or Roth 401(k) contributions (unless otherwise provided by a collective bargaining agreement). During any calendar year in which a participant attains age 50 or older, he or she may elect to make additional pre-tax contributions and/or Roth contributions, called “catch-up” contributions. Unless otherwise provided in a collective bargaining agreement, FE makes a matching contribution of 50% on the first 6% of eligible compensation contributed by an employee. All employer matching contributions are provided as shares in FE common stock, except for certain IBEW Local 777 participants whose matching contributions are made in cash. Catch-up contributions are not eligible for matching contributions. The number of shares of FE common stock contributed to each participant is based on the market price of FE common stock as of the end of each pay period. Plan participants may diversify matching contributions held in FE common stock at any time, subject to certain limitations. Participant Accounts Individual accounts are maintained for each Plan participant. Each participant’s account is credited with the participant’s contributions, employer matching contributions and earnings. The value of an account is updated each business day and participants are vested in the entire value of their account at all times. Investments Participants direct the investment of their contributions and account balances into various investment options including nine LifePath Funds that include a diversified mix of asset classes based on expected retirement dates (commonly referred to as target date funds), fifteen Plan investment options with different objectives covering a range of asset classes and risk levels and a self-managed brokerage account that offers participants the ability to invest in any security listed on the New York Stock Exchange (NYSE), the NYSE MKT LLC (formerly known as the American Stock Exchange or NYSE Amex LLC) or the NASDAQ and a wide range of mutual funds. The Plan’s investment options include a fund of shares of FE common stock, which together with a small portion of cash maintained for liquidity purposes, are recorded on a unit basis. FE’s common shares are traded on the NYSE and participation units in the FE Common Stock Fund are valued at the NYSE closing price on the last business day of the plan year. The valuation per share of FE’s common stock was $44.77 and $39.78 at December 31, 2025 and 2024, respectively. The valuation per unit of the FE Common Stock Fund was $54.50 and $48.46 at December 31, 2025 and 2024, respectively, due to cash maintained in the fund for liquidity purposes. Notes Receivable from Participants Participants may borrow up to 50% of their total account balance, excluding their Roth 401(k) balance, not exceeding $50,000, including loans outstanding and the highest unpaid loan balance over the previous 12 months. The interest rate for new loans is adjusted each quarter to the prime rate plus 1% based on the prime rate on approximately the 15th day of the last month of the preceding quarter. Effective April 1, 2019, the interest rate for new loans will be equal to the prime rate that is published by Reuters on the last day of the month before the start of the calendar quarter in which the loan is approved, plus 1%. The range of interest rates on outstanding loan balances during the year ended December 31, 2025 was 4.25% to 9.75%. Participants may have up to two loans outstanding at one time. The minimum loan amount is $1,000 and must be repaid within 6 to 60 months. If the loan is for the purchase of a principal residence, the loan repayment period can be extended up to 30 years. Principal repayments and payments of interest are credited to the participant’s account when made, generally through payroll deduction. If a participant fails to make regularly scheduled payments, the participant has 90 days from the first missed scheduled repayment to pay the full amount in arrears. If full repayment of the amount in arrears doesn’t occur, the outstanding balance of the loan will be defaulted and become a taxable distribution to the participant. If an eligible participant elects to take full distribution of their account balance and a loan balance remains, the entire loan balance remaining will be taxable. Payment of Benefits Upon termination of service due to disability, retirement or any other reason, a participant may elect to receive the full value or a portion of his or her account, defer payment to a later date (generally, not beyond April 1st of the year following the year the participant reaches age 73) or receive installment payments. In the event of a participant’s death, the participant’s spouse may elect to withdraw all or a portion of the former participant’s account or keep the funds in the Plan in accordance with provisions of the Plan; all other beneficiaries must withdraw or rollover the former participant's account within 180 days. Retired and separated participants with vested balances of $1,000 or less are required to take full distribution of their account. Subsequent Events Management evaluated subsequent events for the Plan through June 26, 2026, the date the financial statements were available to be issued.

The Plan is a defined contribution plan and was established to provide a systematic savings program for eligible employees and to supplement such savings with employer contributions. The Plan is subject to the provisions of the Employee Retirement Income Security Act of 1974, as amended (ERISA), and the Internal Revenue Code of 1986, as amended (IRC).

FirstEnergy Corp. (FE) is the sponsor of the Plan. The FE Savings Plan Committee is the administrator of the Plan and has responsibility for the day-to-day administration of the Plan. Record keeping with respect to individual participant accounts is maintained by Fidelity Workplace Services, LLC. Plan assets are held in trust under an arrangement with Fidelity Management Trust Company.

Generally, all full-time and part-time employees of FE's subsidiaries and participating employees not represented by a collective bargaining union are eligible to participate in the Plan. Full-time and part-time employees represented by a labor union may participate to the extent permitted by their respective collective bargaining agreement.

Unless otherwise provided in a collective bargaining agreement, new employees are automatically enrolled in the Plan with a deemed election to contribute, on a pre-tax basis, 6% of eligible earnings for each payroll period with automatic increases of 1% each April until the employee contribution rate reaches 10%. Automatic enrollment and annual increases can be changed by Plan participants at any time. Plan participants who do not make an affirmative election as to the investment of his or her contributions shall have his or her contributions invested in the age appropriate LifePath Portfolio Fund made available to all Plan participants. A LifePath Portfolio Fund is an investment alternative that provides a mixture of fixed income and equity investments that are matched to an individual’s age and assumed retirement date.

Subject to IRC limitations, the Plan allows each participant to contribute 1% to 75% (unless otherwise provided by a collective bargaining agreement) of their eligible earnings to the Plan through payroll deductions. Participant contributions may be made as before-tax, after-tax or Roth 401(k) contributions (unless otherwise provided by a collective bargaining agreement). During any calendar year in which a participant attains age 50 or older, he or she may elect to make additional pre-tax contributions and/or Roth contributions, called “catch-up” contributions.

Unless otherwise provided in a collective bargaining agreement, FE makes a matching contribution of 50% on the first 6% of eligible compensation contributed by an employee. All employer matching contributions are provided as shares in FE common stock, except for certain IBEW Local 777 participants whose matching contributions are made in cash. Catch-up contributions are not eligible for matching contributions. The number of shares of FE common stock contributed to each participant is based on the market price of FE common stock as of the end of each pay period. Plan participants may diversify matching contributions held in FE common stock at any time, subject to certain limitations.

Participants direct the investment of their contributions and account balances into various investment options including nine LifePath Funds that include a diversified mix of asset classes based on expected retirement dates (commonly referred to as target date funds), fifteen Plan investment options with different objectives covering a range of asset classes and risk levels and a self-managed brokerage account that offers participants the ability to invest in any security listed on the New York Stock Exchange (NYSE), the NYSE MKT LLC (formerly known as the American Stock Exchange or NYSE Amex LLC) or the NASDAQ and a wide range of mutual funds.

The Plan’s investment options include a fund of shares of FE common stock, which together with a small portion of cash maintained for liquidity purposes, are recorded on a unit basis. FE’s common shares are traded on the NYSE and participation units in the FE Common Stock Fund are valued at the NYSE closing price on the last business day of the plan year. The valuation per share of FE’s common stock was $44.77 and $39.78 at December 31, 2025 and 2024, respectively. The valuation per unit of the FE Common Stock Fund was $54.50 and $48.46 at December 31, 2025 and 2024, respectively, due to cash maintained in the fund for liquidity purposes.

Participants may borrow up to 50% of their total account balance, excluding their Roth 401(k) balance, not exceeding $50,000, including loans outstanding and the highest unpaid loan balance over the previous 12 months. The interest rate for new loans is adjusted each quarter to the prime rate plus 1% based on the prime rate on approximately the 15th day of the last month of the preceding quarter. Effective April 1, 2019, the interest rate for new loans will be equal to the prime rate that is published by Reuters on the last day of the month before the start of the calendar quarter in which the loan is approved, plus 1%. The range of interest rates on outstanding loan balances during the year ended December 31, 2025 was 4.25% to 9.75%. Participants may have up to two loans outstanding at one time. The minimum loan amount is $1,000 and must be repaid within 6 to 60 months. If the loan is for the purchase of a principal residence, the loan repayment period can be extended up to 30 years. Principal repayments and payments of interest are credited to the participant’s account when made, generally through payroll deduction. If a participant fails to make regularly scheduled payments, the participant has 90 days from the first missed scheduled repayment to pay the full amount in arrears. If full repayment of the amount in arrears doesn’t occur, the outstanding balance of the loan will be defaulted and become a taxable distribution to the participant. If an eligible participant elects to take full distribution of their account balance and a loan balance remains, the entire loan balance remaining will be taxable.

Upon termination of service due to disability, retirement or any other reason, a participant may elect to receive the full value or a portion of his or her account, defer payment to a later date (generally, not beyond April 1st of the year following the year the participant reaches age 73) or receive installment payments. In the event of a participant’s death, the participant’s spouse may elect to withdraw all or a portion of the former participant’s account or keep the funds in the Plan in accordance with provisions of the Plan; all other beneficiaries must withdraw or rollover the former participant's account within 180 days. Retired and separated participants with vested balances of $1,000 or less are required to take full distribution of their account.