AEP - American Electric Power Company Inc. (via Public) (2024)

Document

AEP RETIREMENT SAVINGS 401(K) PLAN

INDEX

December 31, 2023 and 2022

1

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Benefits Finance Committee has duly caused this annual report to be signed by the undersigned thereunto duly authorized.

AEP Retirement Savings 401(k) Plan

/s/ Julie A. Sherwood

Julie A. Sherwood, SVP Treasury & Risk

June 26, 2024

2

Report of Independent Registered Public Accounting Firm

Benefits Finance Committee and Plan Participants

AEP Retirement Savings 401(k) Plan

Columbus, Ohio

Opinion on the Financial Statements

We have audited the accompanying statements of net assets available for benefits of the AEP Retirement Savings 401(k) Plan (the "Plan") as of December 31, 2023 and 2022, the related statements of changes in net assets available for benefits for the years then ended, and the related notes (collectively, the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the net assets available for benefits of the Plan as of December 31, 2023 and 2022, and the changes in net assets available for benefits for the years then ended, in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

These financial statements are the responsibility of the Plan's management. Our responsibility is to express an opinion on the Plan's financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) ("PCAOB") and are required to be independent with respect to the Plan in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Plan is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Plan's internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risk of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by the Plan's management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

Supplemental Information

The supplemental information in the accompanying Schedule of Assets (Held at End of Year) as of December 31, 2023 has been subjected to audit procedures performed in conjunction with the audit of the Plan's financial statements. The supplemental information is presented for the purpose of additional analysis and is not a required part of the financial statements but included supplemental information required by the Department of Labor's Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974. The supplemental information is the responsibility of the Plan's management. Our audit procedures included determining whether the supplemental information reconciles to the financial statements or the underlying accounting and other records, as applicable, and performing procedures to test the completeness and accuracy of the information presented in the supplemental information. In forming our opinion on the supplemental information, we evaluated whether the supplemental information, including its form and content, is presented in conformity with the Department of Labor's Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974. In our opinion, the supplemental information is fairly stated, in all material respects, in relation to the financial statements as a whole.

/s/ BDO USA, P.C.

We have served as the Plan's auditor since 2021.

Columbus, Ohio

June 26, 2024

3

AEP RETIREMENT SAVINGS 401(K) PLAN

STATEMENTS OF NET ASSETS AVAILABLE FOR BENEFITS

December 31, 2023 and 2022

4

AEP RETIREMENT SAVINGS 401(K) PLAN

STATEMENTS OF CHANGES IN NET ASSETS AVAILABLE FOR BENEFITS

For the Years Ended December 31, 2023 and 2022

5

AEP RETIREMENT SAVINGS 401(K) PLAN

NOTES TO FINANCIAL STATEMENTS

For the Years Ended December 31, 2023 and 2022

1. PLAN DESCRIPTION

The following description of the AEP Retirement Savings 401(k) Plan (Plan) is provided for general information purposes only. Participants should refer to the Plan documents for a more complete description of the Plan's information. The Plan is subject to the provisions of the Employee Retirement Income Security Act of 1974 (ERISA).

General

The Plan is a defined contribution plan that became effective and commenced operations on January 1, 1978. The Plan covers full-time and part-time employees of the participating subsidiaries of American Electric Power Company, Inc. (AEP or the Company) who are not excluded by the terms of the Plan, such as pursuant to a unionized collective bargaining agreement. American Electric Power Service Corporation (AEPSC) is the plan administrator (Plan Administrator) and plan sponsor (Plan Sponsor). AEPSC is a wholly-owned subsidiary of AEP. The Bank of New York Mellon (BNYM) (Trustee) is the primary trustee. Empower Annuity Insurance Company of America (Empower Retirement) is the Plan record keeper. AEPSC appointed Empower Trust Company, LLC (formerly Great-West Trust Company, LLC) as the trustee/custodian for certain cash held on behalf of the Plan pending investment or disbursem*nt.

Contributions

Newly eligible employees are automatically enrolled with a 6% pretax deferral. Such deferrals automatically increase each year by 1% to a maximum of 10%. Employees may opt out of the automatic enrollment or revise their elections after they are notified of their right not to have such pretax deferrals made on their behalf and how their account will be invested in the absence of their making an investment election. Generally, eligible employees participating in the Plan may make contributions (pretax, after-tax or Roth 401(k) contributions) in 1% increments up to 50% of their eligible pay (within Internal Revenue Service (IRS) limits), although pretax and Roth 401(k) amounts are limited to $22,500 for 2023 and $20,500 for 2022. Participants who are age 50 and older are eligible to contribute additional pretax or Roth 401(k) amounts as catch-up contributions. The catch-up contribution limit was $7,500 for 2023 and $6,500 for 2022. An employee who is eligible to participate in the Plan also may roll eligible retirement benefits into the Plan. During the Plan years ended 2023 and 2022, employees rolled in amounts totaling $16,766,691 and $12,704,089, respectively, which are included in participant contributions on the Statements of Changes in Net Assets Available for Benefits. The participating employers contribute to the Plan, on behalf of each participant, an amount equal to 100% of the participant's non-rollover contributions up to 1% of the participant's eligible compensation for each payroll period, plus 70% of the participant's contributions for the next 5% of the participant's eligible compensation for each payroll period, subject to certain limitations. All contributions that are withheld from a participant's pay or are made by the participating employers are deposited in the AEP Retirement Savings 401(k) Plan Trust after each pay period. The Plan, in a manner consistent with the requirements under Section 401 of the Internal Revenue Code (IRC), restricts the amount that certain participants who are deemed highly compensated may contribute to the Plan, provided that it is AEPSC's intent that the Plan include a "qualified automatic contribution arrangement" (as defined in Section 401(k)(13) of the IRC), such that only the after-tax contributions made by such highly compensated participants may be subject to such restrictions.

Notes Receivable from Participants

Participants generally may borrow from their plan accounts a minimum of $1,000 but no more than the lesser of $50,000 or 50% of their account balance. Loan terms range from 12 months to 60 months (or up to 180 months for certain residential loans), or any monthly increment in-between. Interest rates, fixed for the life of the loan, are calculated by adding 1% to the prime rate, as reported in the Wall Street Journal as of the first business day of the calendar month in which the loan is taken.Active employees repay principal and interest payments through payroll deductions.

6

Participant loans and the accrued interest are collateralized by the account balance, and upon default, the outstanding balance is subject to income taxes and possible tax penalty. No allowance for credit losses has been recorded at December 31, 2023 or 2022.

Participant Accounts

Individual accounts are maintained for each Plan participant. Each participant's account is credited with the participant's contributions, the Company's contributions and investment earnings and losses and charged with benefit payments and allocations of Plan expenses. The benefit to which a participant is entitled is the benefit that can be provided from the participant's account.

Participants may transfer the value of their cumulative contributions, in any whole percentage or dollar amount, among investments, and change their investment elections on a daily basis. Participants may change their payroll contribution elections coinciding with the Company's payroll periods.

Participants may make investments in 1% increments among various unitized funds established by the Plan including index funds, bond funds, growth funds, value funds, target date funds, and a stable value fund. The assets of each of the funds are held in the custody of the Trustee, and record-kept at the participant level by Empower Retirement. As the Plan owns the underlying assets of each of these funds, the financial statements present the underlying investments of these unitized funds. In the absence of a participant-directed investment, contributions are invested in a target date fund based on the participant's date of birth which corresponds to an estimated retirement date.

The AEP Stock Fund is an investment option in the Plan. Participants can elect to have dividends generated from their unitized holdings in the AEP Stock Fund paid out in cash, rather than automatically reinvested in the fund. The dividend payouts are made periodically (at least annually) and are treated as ordinary income to the participants for tax purposes.

In addition to the above, the Plan offers a self-directed brokerage account (SDB) option that allows participants to invest in retail mutual funds, exchange traded funds, equities traded on a national securities exchange (other than AEP Stock), preferred stock traded on a national securities exchange and fixed income securities (other than those issued by an affiliate of the Company).

Vesting and Distribution

Participants are immediately vested in their pretax, after-tax, Roth 401(k) and the Company contributions, including earnings thereon; provided that certain matching contributions made to participants of the AEP Energy, Inc. 401(k) Retirement Plan may be only partially vested in accordance with existing vesting positions of this plan.Excluding participants' pretax and Roth 401(k) contributions, profit sharing contributions, and post-2008 Company matching contributions, all participants may make an unlimited number of withdrawals of their interest in the Plan at any time, including their pre-2009 Company matching contributions. Pretax, Roth 401(k) and profit sharing contributions are eligible for withdrawal by participants only after age 59-1/2, or earlier upon hardship (as defined by the Plan), or following termination of employment. Post-2008 Company matching contributions are eligible for withdrawal by participants only after age 59-1/2, or earlier following earlier termination of employment, but not upon hardship.Pursuant to the CARES Act, the Company changed the Plan to allow certain qualified participants impacted by COVID-19 to take withdrawals up to $100,000 between January 1, 2020 and December 30, 2020. These COVID-19 related distributions were not subject to the early withdrawal penalty, or to 20% federal tax withholding; but they were subject to a 10% federal tax withholding requirement, and participants have the option to spread the applicable income tax resulting from the COVID-19 related distribution over a 3 year period. Participant who obtained a COVID-19 related distribution may repay the distribution to an eligible retirement plan within the three-year period following the distribution to defer otherwise applicable taxation.

7

2. ACCOUNTING POLICIES

Basis of Accounting

The accompanying financial statements are prepared on an accrual basis of accounting, in conformity with accounting principles generally accepted in the United States of America (GAAP).

Investment Valuation and Income Recognition

Participants direct the investment of their plan accounts among various investment options offered by the Plan. Investments in securities are reported at fair value while fully benefit-responsive investment contracts are reported at contract value. Fair value of a financial instrument is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.

Purchases and sales of securities have been recorded on a trade-date basis. Net appreciation (depreciation) includes the Plan's gains or losses on investments bought or sold as well as held throughout the year. Interest income is recorded on an accrual basis. Dividends are recorded on the ex-dividend date. These amounts are reinvested by the Trustee in the funds that generated such income with the exception of the AEP Stock Fund, which pays or reinvests dividends at the direction of each participant.

Notes Receivable from Participants

Notes Receivable from Participants are measured at their unpaid principal balance plus any accrued but unpaid interest. Delinquent participant loans are not recorded as distributions until actually distributed based on the terms of the Plan document.

Administrative and Management Fees

Administrative and Management Fees incurred relating to Empower Retirement and BNYM during 2023 and 2022 totaled $715,367 and $2,527,828, respectively. The Plan directly pays for administrative, record keeping and management fees. Fees related to the administration of Notes Receivable from Participants are charged directly to the participant's account and are included in administrative fees. Investment related expenses are included in Investment Advisory and Management Fees.

Distributions to Participants

Distributions to participants are recorded when paid.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of net assets available for benefits and changes therein and disclosure of contingent assets. The estimates and assumptions used are based upon management's evaluation of the relevant facts and circ*mstances as of the date of the financial statements. Actual results could differ from the estimates.

Fair Value Measurements of Assets

The accounting guidance for "Fair Value Measurements and Disclosures" establishes a fair value hierarchy that prioritizes the inputs used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). AEPSC's staff independently monitors valuation policies and procedures and provides members of the Benefits Finance Committee (BFC) and its Investment Subcommittee (IC) various monthly and quarterly reports, regarding compliance with policies and procedures. As of December 31, 2023, the BFC consisted of AEPSC's Chief Financial Officer and Executive Vice President - Portfolio Optimization, Treasurer, Executive Vice President - Chief Human Resources Officer, Senior Vice President -

8

Strategy and Transformation, Executive Vice President - General Counsel and Executive Vice President - Utilities. As of December 31, 2023, the IC consisted of AEPSC's Treasurer, Director of Trusts and Investments, Vice President Finance and Treasury, and two Managing Directors of Corporate Finance.

The Plan utilizes its Trustee's external pricing service to estimate the fair value of the underlying investments held in the Plan. The Plan's investment managers review and validate the prices utilized by the Trustee to determine fair value. The Plan Administrator performs its own valuation testing to verify the fair values of the securities, in part by reviewing audit reports of the Trustee's operating controls and valuation processes.

Assets in the Plan are classified using the following methods. Equities are classified as Level 1 holdings if they are actively traded on exchanges. Items classified as Level 1 are investments in equity securities, exchange traded funds, and registered investment companies. They are valued based on observable inputs primarily unadjusted quoted prices in active markets for identical assets. Level 2 investments consist of significant other observable inputs other than Level 1 prices, such as quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data. Investments with unobservable valuation inputs are classified as Level 3 investments. Investments classified as "Other" are valued using Net Asset Value (NAV) as a practical expedient. The practical expedient is not used when it is determined to be probable that the investments will sell for an amount different than the reported NAV. Items classified as Other are primarily common/collective trusts. These investments do not have a readily determinable fair value or they contain redemption restrictions which may include the right to suspend redemptions under certain circ*mstances. Redemption restrictions on common/collective trusts may also prevent certain investments from being redeemed at the reporting date for the underlying value. There are no unfunded commitments for investments in common/collective trusts.

9

3. PLAN TERMINATION

Although it has not expressed any intent to do so, AEPSC has the right to take such actions as will allow contributions to the Plan to be discontinued at any time and to terminate the Plan subject to the provisions of ERISA. In the event of Plan termination, affected participants would be made 100 percent vested in their accounts.

10

4. INVESTMENT CONTRACTS

The Plan's Managed Income Fund provides a stable value investment option that includes fully benefit-responsive synthetic investment wrap contracts which assure the book value of investments in that fund for Plan participants. The fund's underlying assets, which are held in a trust, utilize wrap contracts issued by four financial institutions as of December 31, 2023 and 2022. The fund's underlying investment or investments, usually a portfolio owned by the Plan, consist primarily of high quality, intermediate term fixed income securities and guaranteed investment contracts. The contracts provide that participants execute plan transactions at contract value. Contract value represents contributions made to the fund, plus credited interest, less participant withdrawals, without regard to changes in the fair value of the investments and securities underlying the fund. The rates for crediting interest are reset periodically based on market rates of other similar investments, the current yield of the underlying investments and the spread between the market value and contract value. The interest crediting rate cannot be less than 0%. Certain events initiated by the Plan Sponsor, such as a plan termination or a plan merger, would limit the ability of the Plan to administer participant-level transactions at contract value or may allow for the termination of the wrap contract at market value, rather than contract value.

The Plan Sponsor does not believe that any events that may limit the ability of the Plan to transact at contract value are probable as of December 31, 2023 or the date these financial statements are issued.

11

5. RELATED PARTY AND PARTY-IN-INTEREST TRANSACTIONS

Certain transactions involving the Plan and its assets during 2023 and 2022 involved parties in interest with respect to the Plan, but those transactions were not prohibited transactions under ERISA because of the applicability of one or more exemptions. The exempt party-in-interest transactions involving the Plan included the following: (1) BNYM has acted as trustee and custodian under the Plan, while Mellon, an affiliate has acted as an investment manager in connection with the index funds held under the Plan's investment options and (2) Empower Trust Company, LLC has been acting as a trustee and custodian under the Plan, while its affiliates have acted as (a) the Plan's record keeper and (b) investment advisor or investment manager for a number of plan participants with respect to the amounts held in their Plan accounts. Notes receivable from participants held by the Plan are also considered party-in-interest transactions. Certain investments within the self-directed brokerage account are considered party-in-interest transactions.

As of December 31, 2023 and 2022, the Plan held 3,349,383and 3,303,820 shares, respectively, of common stock of American Electric Power Company, Inc., the parent company of the Plan Sponsor, with a cost basis of$196,757,008 and $185,079,875, respectively. During the year ended December 31, 2023, the Plan acquired 361,574 shares of that common stock with a fair value of $30,007,997 and disposed of 260,525 shares with a fair value of $15,107,083. During the year ended December 31, 2022, the Plan acquired 176,277 shares of that common stock with a fair value of $16,186,546 and disposed of 433,830 shares with a fair value of $23,595,217. During the years ended December 31, 2023 and 2022, the Plan recorded dividend income of $11,355,804 and $10,742,029, respectively, related to its investment in that common stock.

12

6. FAIR VALUE MEASUREMENTS

For a discussion of fair value accounting and the classification of assets within the fair value hierarchy, see the "Fair Value Measurements of Assets" section of Note 2.

Plan Assets within the Fair Value Hierarchy as of December 31, 2023

(a)Amounts in "Other" column represent investments for which fair value is measured using net asset value per share as practical expedient.

13

Plan Assets within the Fair Value Hierarchy as of December 31, 2022

(a)Amounts in "Other" column represent investments for which fair value is measured using net asset value per share.

14

The following tables set forth a summary of the Plan's investments measured at Net Asset Value as a practical expedient as of December 31, 2023 and 2022:

Fair Value Estimated Using Net Asset Value per Share as of December 31, 2023

Fair Value Estimated Using Net Asset Value per Share as of December 31, 2022

It is the Plan's policy to record transfers in and transfers out of each level at the end of each reporting period. There have been no transfers between Level 1, Level 2, and Level 3 during the years ended December 31, 2023 and 2022.

15

7. RISK AND UNCERTAINTIES

The Plan invests in various investment instruments, and investment securities are exposed to various risks, such as interest rate, credit and market volatility. Due to the level of risk associated with certain investment securities, it is reasonably possible that changes in the values of investment securities will occur in the near term and that such changes could materially affect participants' account balances and the amounts reported in the financial statements.

16

8. FEDERAL INCOME TAX

The IRS has issued a favorable determination letter dated December 8, 2017 with respect to the Plan. A favorable determination letter indicates that, in the opinion of the IRS, the terms of the Plan meets the requirements of Section 401(a) of the IRC, and thereby recognizes the exempt status of the Plan's trust pursuant to Section 501(a) of the IRC.

The Plan has been amended subsequent to the issuance of thatIRS determination letter. Plan management believes that the Plan is currently designed and operated in compliance with the applicable requirements of the IRC and that the Plan's trust continues to be tax-exempt. Therefore, no provision for income taxes has been included in the Plan's financial statements.

The Plan Administrator is required to evaluate tax positions taken by the Plan and recognize a tax liability (or asset) if the Plan has taken an uncertain position that more than likely than not would not be sustained upon examination by the IRS. The Plan Administrator has analyzed the tax positions taken by the Plan, and has concluded that as of December 31, 2023, there are no uncertain positions taken or expected to be taken that would require recognition of a liability (or asset) or disclosure in the financial statements. The Plan is subject to routine audits by taxing jurisdictions; however, there are currently no audits for any tax periods in progress.

9. SUBSEQUENT EVENTS

The Plan evaluated subsequent events from December 31, 2023 through June 26, 2024, the date these financial statements were available to be issued. The Plan is not aware of any subsequent events that would require recognition or disclosure in the financial statements.

17

10. RECONCILIATION OF FINANCIAL STATEMENTS TO THE FORM 5500

The following tables are reconciliations of participant loans and net assets available for benefits per the financial statements to the Form 5500.

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

AEP RETIREMENT SAVINGS 401(K) PLAN

EXHIBIT INDEX

64