Filed pursuant to Rule 424(b)(5)
Registration No. 333-222068

The information in this preliminary prospectus supplement is not complete and may be changed. Neither this preliminary prospectus supplement nor the accompanying prospectus is an offer to sell the securities and neither is soliciting any offer to buy the securities in any jurisdiction where the offer or sale is not permitted.

Subject to Completion, dated November 28, 2018

Preliminary Prospectus Supplement

(To Prospectus dated December 14, 2017)

American Electric Power Company, Inc.

$                % Senior Notes, Series I, due

$                % Senior Notes, Series J, due

Interest on the Series I Notes and the Series J Notes (collectively, the “Notes”) is payable semi-annually on June 1 and December 1 of each year, beginning June 1, 2019. The Series I Notes will mature on December 1,                . The Series J Notes will mature on December 1,                . We may not redeem the Series I Notes. We may redeem the Senior J Notes either in whole or in part at our option at any time, and from time to time, at the applicable redemption price described below under “Specific Terms of the Notes—Optional Redemption” on page S-8 of this prospectus supplement. The Notes do not have the benefit of a sinking fund.

The Notes are unsecured and rank equally with all of our other unsecured and unsubordinated indebtedness from time to time outstanding and will be effectively subordinated to all of our secured debt, to the extent of the assets securing such debt. We will issue the Notes only in registered form in denominations of $2,000 and integral multiples of $1,000 in excess thereof.

INVESTING IN THESE NOTES INVOLVES RISKS. SEE THE SECTION ENTITLED “RISK FACTORS” ON PAGE S-5 OF THIS PROSPECTUS SUPPLEMENT FOR MORE INFORMATION.

Neither the U.S. Securities and Exchange Commission nor any state securities commission has approved or disapproved of the Notes or determined that this prospectus supplement or the accompanying prospectus is accurate or complete. Any representation to the contrary is a criminal offense.

The Notes are expected to be delivered in book-entry form only through The Depository Trust Company for the accounts of its participants, including Clearstream Banking, société anonyme, Luxembourg and Euroclear Bank S.A./N.V., on or about November     , 2018.

Joint Book-Running Managers

November         , 2018

TABLE OF CONTENTS

Prospectus Supplement

ABOUT THIS PROSPECTUS SUPPLEMENT

This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of this offering of the Notes and also adds to and updates information contained in the accompanying prospectus and the documents incorporated by reference in this prospectus supplement and the accompanying prospectus. The second part is the accompanying prospectus, which gives more general information, some of which does not apply to the Notes. If the description of the Notes varies between this prospectus supplement and the accompanying prospectus, you should rely on the information in this prospectus supplement.    

You should rely only on the information contained or incorporated by reference in this prospectus supplement and in the accompanying prospectus and in any written communication from the Company or the underwriters specifying the final terms of the offering. We have not, and the underwriters have not, authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. You should assume that the information appearing in this prospectus supplement and the accompanying prospectus is accurate as of the date on their respective covers. Our business, financial condition, results of operations and prospects may have changed since those dates.

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RISK FACTORS

Investing in the Notes involves risk. You should carefully consider the risks and uncertainties described below as well as any cautionary language or other information contained or incorporated by reference in this prospectus supplement and the accompanying prospectus, including “Item 1A. Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2017, along with certain amended and restated risk factors contained in our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2018, June 30, 2018 and September 30, 2018 before investing in the Notes. Before making an investment decision, you should carefully consider these risks as well as other information contained or incorporated by reference in this prospectus supplement and the accompanying prospectus. The risks and uncertainties described are those presently known to us.

We must rely on cash from our subsidiaries to make payments on the Notes.

We are a holding company that derives substantially all of our income from our operating subsidiaries. Our subsidiaries are separate and distinct legal entities and have no obligation to pay any amounts on the Notes or to make any funds available for such payment. Therefore, the Notes will be effectively subordinated to all existing and future indebtedness and other liabilities, including trade payables, debt and preferred stock incurred or issued by our subsidiaries. In addition to trade liabilities, many of our operating subsidiaries incur debt in order to finance their business activities. All of this indebtedness will be effectively senior to the Notes. In addition, each subsidiary’s ability to pay dividends to us depends on any statutory, regulatory and/or contractual restrictions that may be applicable to such subsidiary. The indenture pursuant to which the Notes will be issued does not place any limit on the amount of senior indebtedness that we may issue, guarantee or otherwise incur or the amount of liabilities, including debt or preferred stock that our subsidiaries may issue, guarantee or otherwise incur. We expect that our subsidiaries will from time to time incur additional indebtedness and other liabilities that will be senior to the Notes. At September 30, 2018, the total indebtedness of our subsidiaries was $22.580 billion; this amount does not include other liabilities.

WHERE YOU CAN FIND MORE INFORMATION

This prospectus supplement and the accompanying prospectus are part of a registration statement we filed with the Securities and Exchange Commission (“SEC”). We also file annual, quarterly and special reports and other information with the SEC. You may examine our SEC filings through the SEC’s website at http://www.sec.gov.

The SEC allows us to “incorporate by reference” the information we file with them, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus supplement and the accompanying prospectus, and later information that we file with the SEC will automatically update and supersede this information. We incorporate by reference the documents listed below and any future filings made with the SEC under Sections 13(a), 13(c), 14, or 15(d) of the Securities Exchange Act of 1934, as amended (the “1934 Act”) until we sell all the Notes.

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You may request a copy of these filings, at no cost, by writing or telephoning us at the following address:

Investor Relations

American Electric Power Service Corporation

1 Riverside Plaza

Columbus, Ohio 43215

614-716-1000

You should rely only on the information incorporated by reference or provided in this prospectus supplement, the accompanying prospectus and in any written communication from us or any underwriter specifying the final terms of the offering. We have not authorized anyone else to provide you with different information. We are not making an offer of the Notes in any state or jurisdiction where the offer is not permitted. You should assume that the information appearing in this prospectus supplement and the accompanying prospectus is accurate as of the date on their respective covers.

USE OF PROCEEDS

We estimate that the net proceeds from the sale of the Notes offered hereby, after deducting the underwriting discounts and our estimated offering expenses, will be approximately $                million and will be used for general corporate purposes. These purposes include the repayment of short term indebtedness. If we do not use the net proceeds immediately, we will temporarily invest them in short-term, interest-bearing obligations.    

SPECIFIC TERMS OF THE NOTES

Please read the following information concerning the Notes in conjunction with the statements under “Description of the Senior Notes” in the accompanying prospectus, which the following information supplements and, in the event of any inconsistencies, supersedes. The following description does not purport to be complete and is subject to, and is qualified in its entirety by reference to, the description in the accompanying prospectus and the Indenture dated as of May 1, 2001 (the “Indenture”) between us and The Bank of New York Mellon Trust Company, N.A., as trustee (the “Trustee”). The Indenture is described in the accompanying prospectus, and a form thereof is filed as an exhibit to the registration statement under which the Notes are being offered and sold.

The Notes will be our unsecured and unsubordinated obligations ranking equally with our other outstanding unsecured and unsubordinated indebtedness. At September 30, 2018, we had approximately $2.731 billion of outstanding unsecured and unsubordinated indebtedness. The

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Indenture contains no restrictions on the amount of additional indebtedness that we may issue. We currently have no secured debt outstanding.

Principal Amount, Maturity, Interest and Payment

The Series I Notes and the Series J Notes will initially be issued in an aggregate principal amount of $                and $                 , respectively. We may at any time and from time to time, without consent of the holders of either series of the Notes, issue additional notes having the same ranking, interest rate, maturity and other terms (except the public offering price, issue date and, if applicable, the initial interest payment date) as the applicable Notes. These notes, together with the applicable Notes, will be a single series of notes under the Indenture.

The Series I Notes will mature and become due and payable, together with any accrued and unpaid interest, on December 1,                , and will bear interest at the rate of                % per year from November                , 2018 until December 1,                . The Series I Notes are not subject to any sinking fund provision.

The Series J Notes will mature and become due and payable, together with any accrued and unpaid interest, on December 1,                , and will bear interest at the rate of                % per year from November                , 2018 until December 1,                . The Series J Notes are not subject to any sinking fund provision.

Interest on each Note will be payable semi-annually in arrears on June 1 and December 1 of each year and at redemption, if any, or maturity. The initial interest payment date is June 1, 2019. Each payment of interest shall include interest accrued through the day before such interest payment date. Interest on the Notes will be computed on the basis of a 360-day year consisting of twelve 30-day months.

We will pay interest on the Notes (other than interest payable at redemption, if any, or maturity) in immediately available funds to the owners of the Notes as of the Regular Record Date (as defined below) for each interest payment date. We will pay the principal of the Notes and any premium and interest payable at redemption, if any, or at maturity in immediately available funds delivered to the Trustee, and the Trustee will forward such funds to the applicable depositary for payments to its participants for subsequent disbursement to the beneficial owners of the Notes. See – Global Clearance and Settlement Procedures.

The Notes will be issued in registered form in denominations of $2,000 and integral multiples of $1,000 in excess thereof.

If any interest payment date, redemption date or the maturity is not a Business Day (as defined below), we will pay all amounts due on the next succeeding Business Day and no additional interest will be paid, except that if such Business Day is in the next succeeding calendar month, we will make payment on the immediately preceding Business Day.

The “Regular Record Date” will be the close of business on the                 or                 prior to the relevant interest payment date, whether or not a Business Day.

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“Business Day” means any day that is not a day on which banking institutions in New York City are authorized or required by law or regulation to close.

Waiver of Replacement Capital Covenant

The Indenture provides that the Notes will not be entitled to benefit in any way from the Replacement Capital Covenant, dated as of March 1, 2008, entered into by the Company in favor of certain holders of the Company’s debt, and subsequently amended by an amendment dated as of February 29, 2012 (as amended, the “Replacement Capital Covenant”). Under this provision, the Notes will never become Eligible Debt or Covered Debt (as such terms are defined in the Replacement Capital Covenant), and the holders of the Notes will never be entitled to become Covered Debtholders (as defined in the Replacement Capital Covenant). Any person purchasing or otherwise acquiring a Note or any interest in a Note will be deemed to have agreed to this waiver of the Replacement Capital Covenant.

Optional Redemption

The Series I Notes are not subject to redemption prior to maturity.

At any time prior to                ,                (                 months prior to the maturity date (the “Par Call Date”)), we may redeem the Series J Notes either as a whole or in part at a redemption price equal to the greater of (1) 100% of the principal amount of the Series J Notes being redeemed and (2) the sum of the present values of the remaining scheduled payments of principal and interest on the Series J Notes being redeemed that would be due if such Series J Notes matured on the Par Call Date (excluding the portion of any such interest accrued to but excluding the date of redemption) discounted (for purposes of determining present value) to the redemption date on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) at the Treasury Rate (as defined below) plus                basis points, plus, in each case, accrued and unpaid interest thereon to but excluding the date of redemption.

At any time on or after the Par Call Date, we may redeem the Series J Notes in whole or in part at 100% of the principal amount of the Series J Notes being redeemed, plus accrued and unpaid interest thereon to but excluding the date of redemption.

“Comparable Treasury Issue” means the United States Treasury security selected by an Independent Investment Banker as having a maturity comparable to the remaining term (“remaining life”) of the Series J Notes (assuming, for this purpose, that the Series J Notes matured on the Par Call Date) that would be utilized, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining life of the Series J Notes.

“Comparable Treasury Price” means, with respect to any redemption date, (1) the average of the Reference Treasury Dealer Quotations for such redemption date, after excluding the highest and lowest of such Reference Treasury Dealer Quotations, or (2) if we obtain fewer than four of such Reference Treasury Dealer Quotations, the average of all such quotations.

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“Independent Investment Banker” means one of the Reference Treasury Dealers appointed by us and notified by us to the Trustee.

“Reference Treasury Dealer” means a primary U.S. Government securities dealer or dealers selected by us and notified by us to the Trustee.

“Reference Treasury Dealer Quotations” means, with respect to each Reference Treasury Dealer and any redemption date, the average, as determined by us and notified to the Trustee, of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to us and the Trustee by such Reference Treasury Dealer at or before 3:30 p.m., New York City time, on the third Business Day preceding such redemption date.

“Treasury Rate” means, with respect to any redemption, the rate per annum equal to the semiannual equivalent yield to maturity of the Comparable Treasury Issue, calculated using a price for the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for such redemption date.

Restrictive Covenants Relating to the Notes

Limitation upon Liens on Stock of Certain Subsidiaries

For so long as any Notes remain outstanding, we will not create or incur or allow any of our subsidiaries to create or incur any pledge or security interest on any of the capital stock of a Public Utility Subsidiary held by us or one of our subsidiaries or a Significant Subsidiary.

For purposes of this covenant, a Public Utility Subsidiary means, at any particular time, a direct or indirect subsidiary of ours that, as a substantial part of its business, distributes or transmits electric energy to retail or wholesale customers at rates or tariffs that are regulated by either a state or Federal regulatory authority.

For purposes of this covenant, Significant Subsidiary means, at any particular time, any direct subsidiary of ours whose consolidated gross assets or consolidated gross revenues (having regard to our direct beneficial interest in the shares, or the like, of that subsidiary) represent at least 25% of our consolidated gross assets or our consolidated gross revenues.

Limitation upon Mergers, Consolidations and Sale of Assets

Nothing in the Indenture or the Notes prevents us from consolidating or merging with or into, or selling or otherwise disposing of all or substantially all of our property to another entity, provided that (1) we agree to obtain a supplemental indenture pursuant to which the surviving entity or transferee agrees to assume our obligations relating to all outstanding debt securities issued under the Indenture and (2) the surviving entity or transferee is organized under the laws of the United States, any state thereof or the District of Columbia.

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Global Clearance and Settlement Procedures

Secondary market trading between Clearstream Banking, société anonyme, Luxembourg (“Clearstream”) participants and/or Euroclear Bank S.A./N.V., as operator of the Euroclear system (“Euroclear”) participants will occur in the ordinary way in accordance with the applicable rules and operating procedures of Clearstream and Euroclear, as applicable.

Cross-market transfers between persons holding directly or indirectly through DTC on the one hand, and directly or indirectly through Clearstream participants or Euroclear system participants on the other, will be effected through DTC in accordance with DTC rules on behalf of the relevant European international clearing system by its U.S. depositary; however, such cross-market transactions will require delivery of instructions to the relevant European international clearing system by the counterparty in such system in accordance with its rules and procedures and within its established deadlines (European time). The relevant European international clearing system will, if the transaction meets its settlement requirements, deliver instructions to its U.S. depositary to take action to effect final settlement on its behalf by delivering or receiving securities in DTC, and making or receiving payment in accordance with normal procedures for same-day funds settlement applicable to DTC. Clearstream participants and Euroclear system participants may not deliver instructions directly to their respective U.S. depositaries.

Because of time-zone differences, credits of Notes received in Clearstream or the Euroclear system as a result of a transaction with a DTC participant will be made during subsequent securities settlement processing and dated the business day following the DTC settlement date. Such credits or any transactions in such Notes settled during such processing will be reported to the relevant Euroclear system participant or Clearstream participant on such business day. Cash received in Clearstream or the Euroclear system as a result of sales of the Notes by or through a Clearstream participant or a Euroclear system participant to a DTC participant will be received with value on the DTC settlement date but will be available in the relevant Clearstream or the Euroclear system cash account only as of the business day following settlement in DTC.

Additional Information

For additional important information about the Notes, see “Description of the Senior Notes” in the accompanying prospectus, including: (i) additional information about the terms of the Notes, (ii) general information about the Indenture and the Trustee, and (iii) a description of events of default under the Indenture.

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CERTAIN UNITED STATES FEDERAL INCOME AND ESTATE TAX

CONSEQUENCES TO NON-U.S. HOLDERS

The following is a summary of certain United States federal income and estate tax consequences of the purchase, ownership and disposition of the Notes as of the date hereof. This summary deals only with Notes that are held as capital assets by a non-U.S. holder (as defined below) who acquires the Notes upon original issuance at their initial offering price.

A “non-U.S. holder” means a beneficial owner of the Notes (other than an entity or arrangement treated as a partnership for United States federal income tax purposes) that is not, for United States federal income tax purposes, any of the following:

This summary is based upon provisions of the Internal Revenue Code of 1986, as amended (the “Code”), and regulations, rulings and judicial decisions as of the date hereof. Those authorities may be changed, perhaps retroactively, so as to result in United States federal income and estate tax consequences different from those summarized below. This summary does not address all aspects of United States federal income and estate taxes and does not deal with foreign, state, local or other tax consequences that may be relevant to non-U.S. holders in light of their personal circumstances. In addition, it does not represent a detailed description of the United States federal income and estate tax consequences applicable to you if you are subject to special treatment under the United States federal income tax laws (including if you are a United States expatriate, “controlled foreign corporation,” “passive foreign investment company” or a partnership or other pass-through entity for United States federal income tax purposes). We cannot assure you that a change in law will not alter significantly the tax consequences that we describe in this summary.

If a partnership (or other entity or arrangement treated as a partnership for United States federal income tax purposes) holds the Notes, the tax treatment of a partner will generally depend upon the status of the partner and the activities of the partnership. If you are a partner of a partnership holding the Notes, you should consult your tax advisors.

It is anticipated, and this discussion assumes, that the Notes will not be issued with more than a de minimis amount of original issue discount for United States federal income tax purposes.

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If you are considering the purchase of Notes, you should consult your own tax advisors concerning the particular United States federal income and estate tax consequences to you of the purchase, ownership and disposition of the Notes, as well as the consequences to you arising under other United States federal tax laws and the laws of any other taxing jurisdiction.

United States Federal Withholding Tax

Subject to the discussions of backup withholding and FATCA below, United States federal withholding tax will not apply to any payment of interest on the Notes under the “portfolio interest rule,” provided that:

If you cannot satisfy the requirements described above, payments of interest made to you will be subject to a 30% United States federal withholding tax, unless you provide the applicable withholding agent with a properly executed:

Subject to the discussion of FATCA below, the 30% United States federal withholding tax generally will not apply to any payment of principal or gain that you realize on the sale, exchange, retirement, redemption or other taxable disposition of a Note.

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United States Federal Income Tax

If you are engaged in a trade or business in the United States and interest on the Notes is effectively connected with the conduct of that trade or business (and, if required by an applicable income tax treaty, is attributable to a permanent establishment or fixed base that you maintain in the United States), then you will be subject to United States federal income tax on that interest on a net income basis in the same manner as if you were a United States person as defined under the Code. In addition, if you are a foreign corporation, you may be subject to a branch profits tax equal to 30% (or lower applicable branch profits tax rate under an income tax treaty) of your effectively connected earnings and profits, subject to adjustments. Any effectively connected interest will be exempt from the 30% United States federal withholding tax, provided the certification requirements discussed above in “—United States Federal Withholding Tax” are satisfied.

Subject to the discussions of backup withholding and FATCA below, any gain realized on the sale, exchange, retirement, redemption or other taxable disposition of a Note generally will not be subject to United States federal income tax unless:

United States Federal Estate Tax

If you are an individual and are not a United States citizen and are not a resident of the United States (as specifically defined for United States federal estate tax purposes), your estate will not be subject to United States federal estate tax on Notes beneficially owned by you at the time of your death, provided that any payment to you of interest on the Notes, if received at such time, would be eligible for exemption from the 30% United States federal withholding tax under the “portfolio interest rule” described above under “—United States Federal Withholding Tax,” without regard to the statement requirement described in the fifth bullet point of that section.

Information Reporting and Backup Withholding

Interest paid to you and the amount of tax, if any, withheld with respect to those payments generally will be reported to the IRS. Copies of the information returns reporting such interest payments and any withholding may also be made available to the tax authorities in the country in which you reside under the provisions of an applicable income tax treaty.

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In general, you will not be subject to backup withholding with respect to payments on the Notes that we make to you provided that the applicable withholding agent does not have actual knowledge or reason to know that you are a United States person as defined under the Code, and such withholding agent has received from you the statement described above in the fifth bullet point under “—United States Federal Withholding Tax.”

Information reporting and, depending on the circumstances, backup withholding will apply to the proceeds of a sale or other taxable disposition of Notes made within the United States or conducted through certain United States-related financial intermediaries, unless you certify under penalties of perjury that you are a non-U.S. holder (and the payor does not have actual knowledge or reason to know that you are a United States person as defined under the Code), or you otherwise establish an exemption.

Backup withholding is not an additional tax and any amounts withheld under the backup withholding rules will be allowed as a refund or a credit against your United States federal income tax liability provided the required information is timely furnished to the IRS.

Additional Withholding Requirements

Under sections 1471 through 1474 of the Code (such sections commonly referred to as “FATCA”), a 30% United States federal withholding tax generally will apply to any interest income paid on the Notes and, for a disposition (including a redemption) of a Note occurring after December 31, 2018, including the return of principal, the gross proceeds from such disposition, in each case paid to (i) a “foreign financial institution” (as specifically defined in the Code) which does not provide sufficient documentation, typically on IRS Form W-8BEN-E, evidencing either (x) an exemption from FATCA, or (y) its compliance (or deemed compliance) with FATCA (which may alternatively be in the form of compliance with an intergovernmental agreement with the United States) in a manner which avoids withholding, or (ii) a “non-financial foreign entity” (as specifically defined in the Code) which does not provide sufficient documentation, typically on IRS Form W-8BEN-E, evidencing either (x) an exemption from FATCA, or (y) adequate information regarding certain substantial United States beneficial owners of such entity (if any). If an interest payment is both subject to withholding under FATCA and subject to the withholding tax discussed above under “— United States Federal Withholding Tax,” the withholding under FATCA may be credited against, and therefore reduce, such other withholding tax. You should consult your own tax advisors regarding these rules and whether they may be relevant to your ownership and disposition of the Notes.

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UNDERWRITING

Barclays Capital Inc. and Morgan Stanley & Co. LLC are acting as representatives of the underwriters named below with respect to the Notes. Subject to the terms and conditions of the underwriting agreement, we have agreed to sell to each of the underwriters named below and each of the underwriters has severally and not jointly agreed to purchase from us the respective principal amount of Notes set forth opposite its name below:

In the underwriting agreement, the underwriters have agreed, subject to the terms and conditions set forth therein, to purchase all of the Notes offered hereby if any of the Notes are purchased.

The expenses associated with the offer and sale of the Notes, excluding the underwriting discounts, are expected to be approximately $                 and will be payable by us.

The underwriters propose to offer the Notes to the public initially at the public offering price set forth on the cover page of this prospectus supplement and may offer the Notes to certain dealers initially at that price less a concession not in excess of not in excess of                % per Series I Note and not in excess of                % per Series J Note. The underwriters may allow, and those dealers may reallow, a discount not in excess of                % per Series I Note and not in excess of                % per Series J Note to certain other dealers. After the initial public offering, the public offering price, concession and discount may be changed.

Prior to this offering, there has been no public market for the Notes. The Notes will not be listed on any securities exchange or automated quotation system. Certain underwriters have advised us that they intend to make a market in the Notes. The underwriters will have no obligation to make a market in the Notes, however, and may cease market making activities, if commenced, at any time. There can be no assurance of a secondary market for the Notes, or that the Notes may be resold.

We have agreed to indemnify the several underwriters against certain liabilities, including liabilities under the Securities Act of 1933, as amended, or contribute to payments that each underwriter may be required to make in respect thereof.

In connection with the offering, the underwriters may purchase and sell the Notes in the open market. These transactions may include over-allotment and stabilizing transactions and

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purchases to cover syndicate short positions created in connection with the offering. Stabilizing transactions consist of certain bids or purchases for the purposes of preventing or retarding a decline in the market price of the Notes and syndicate short positions involve the sale by the underwriters of a greater number of Notes than they are required to purchase from us in the offering. The underwriters also may impose a penalty bid, whereby selling concessions allowed to syndicate members or other broker dealers in respect of the securities sold in the offering for their account may be reclaimed by the syndicate if such Notes are repurchased by the syndicate in stabilizing or covering transactions. These activities may stabilize, maintain or otherwise affect the market price of the Notes, which may be higher than the price that might otherwise prevail in the open market, and these activities, if commenced, may be discontinued at any time. These transactions may be effected in the over-the-counter market or otherwise.

The underwriters and their respective affiliates are full service financial institutions engaged in various activities, which may include sales and trading, commercial and investment banking, advisory, investment management, investment research, principal investment, hedging, market making, brokerage and other financial and non-financial activities and services. In the ordinary course of their various business activities, the underwriters and their respective affiliates have made or held, and may in the future make or hold, a broad array of investments including serving as counterparties to certain derivative and hedging arrangements, and may have actively traded, and, in the future may actively trade, debt and equity securities (or related derivative securities), and financial instruments (including bank loans) for their own account and for the accounts of their customers and may have in the past and at any time in the future hold long and short positions in such securities and instruments. Such investment and securities activities may have involved, and in the future may involve, securities and instruments of the Company.

If any of the underwriters or their affiliates have a lending relationship with us, certain of those underwriters or their affiliates routinely hedge, and certain other of those underwriters or their affiliates may hedge, their credit exposure to us consistent with their customary risk management policies. Typically, these underwriters and their affiliates would hedge such exposure by entering into transactions which consist of either the purchase of credit default swaps or the creation of short positions in our securities, including potentially the Notes offered hereby. Any such credit default swaps or short positions could adversely affect future trading prices of the Notes offered hereby. The underwriters and their affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

Some of the underwriters or their affiliates engage in transactions with, and have performed services for, us and our affiliates in the ordinary course of business and have, from time to time, performed, and may in the future perform, various financial advisory, corporate trust, commercial and investment banking services for us, for which they received, or will receive, customary fees and expenses.

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Selling Restrictions

Notice to Prospective Investors in the European Economic Area

The Notes are not intended to be offered, sold or otherwise made available to and should not be offered, sold or otherwise made available to any retail investor in the European Economic Area (“EEA”). For these purposes, a retail investor means a person who is one (or more) of: (i) a retail client as defined in point (11) of Article 4(1) of Directive 2014/65/EU (as amended, “MiFID II”); or (ii) a customer within the meaning of Directive 2002/92/EC (as amended, the “Insurance Mediation Directive”), where that customer would not qualify as a professional client as defined in point (10) of Article 4(1) of MiFID II; or (iii) not a qualified investor as defined in Directive 2003/71/EC (as amended, the “Prospectus Directive”). Consequently, no key information document required by Regulation (EU) No 1286/2014 (as amended, the “PRIIPs Regulation”) for offering or selling the Notes or otherwise making them available to retail investors in the EEA has been prepared and therefore offering or selling the Notes or otherwise making them available to any retail investor in the EEA may be unlawful under the PRIIPs Regulation. This prospectus supplement and the accompanying prospectus have been prepared on the basis that any offer of Notes in any Member State of the EEA will be made pursuant to an exemption under the Prospectus Directive from the requirement to publish a prospectus for offers of Notes. This prospectus supplement and the accompanying prospectus are not a prospectus for the purposes of the Prospectus Directive.

Notice to Prospective Investors in the United Kingdom

This document is only being distributed to and is only directed at persons in the United Kingdom who are “qualified investors (as defined in the Prospectus Directive) (i) who have professional experience in matters relating to investments falling within Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005 (as amended, the “Order”) and/or (ii) who are high net worth companies (or other persons to whom it may otherwise be lawfully communicated) falling within Article 49(2)(a) to (d) of the Order (all such persons together being referred to as “relevant persons”). The Notes are only available to, and any invitation, offer or agreement to subscribe, purchase or otherwise acquire such Notes will be engaged in only with, relevant persons. Any person who is not a relevant person should not act or rely on this prospectus supplement and the accompanying prospectus or any of their contents.

Each underwriter agrees that:

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Notice to Residents of Canada

The Notes may be sold only to purchasers purchasing, or deemed to be purchasing, as principal that are accredited investors, as defined in National Instrument 45-106 Prospectus Exemptions or subsection 73.3(1) of the Securities Act (Ontario), and are permitted clients, as defined in National Instrument 31-103 Registration Requirements, Exemptions and Ongoing Registrant Obligations. Any resale of the Notes must be made in accordance with an exemption from, or in a transaction not subject to, the prospectus requirements of applicable securities laws.

Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if this prospectus supplement (including any amendment thereto) contains a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province or territory. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province or territory for particulars of these rights or consult with a legal advisor.

Pursuant to section 3A.3 of National Instrument 33-105 Underwriting Conflicts (NI 33-105), the underwriters are not required to comply with the disclosure requirements of NI 33-105 regarding underwriter conflicts of interest in connection with this offering.

Notice to Prospective Investors in Hong Kong

The Notes may not be offered or sold by means of any document other than (i) in circumstances which do not constitute an offer to the public within the meaning of the Companies Ordinance (Cap.32, Laws of Hong Kong), or (ii) to “professional investors” within the meaning of the Securities and Futures Ordinance (Cap.571, Laws of Hong Kong) and any rules made thereunder, or (iii) in other circumstances which do not result in the document being a “prospectus” within the meaning of the Companies Ordinance (Cap.32, Laws of Hong Kong), and no advertisement, invitation or document relating to the Notes may be issued or may be in the possession of any person for the purpose of issue (in each case whether in Hong Kong or elsewhere), which is directed at, or the contents of which are likely to be accessed or read by, the public in Hong Kong (except if permitted to do so under the laws of Hong Kong) other than with respect to Notes which are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” within the meaning of the Securities and Futures Ordinance (Cap. 571, Laws of Hong Kong) and any rules made thereunder.

Notice to Prospective Investors in Singapore

This prospectus supplement has not been registered as a prospectus with the Monetary Authority of Singapore. Accordingly, this prospectus supplement and any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the

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Notes may not be circulated or distributed, nor may the Notes be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to persons in Singapore other than (i) to an institutional investor under Section 274 of the Securities and Futures Act, Chapter 289 of Singapore (the “SFA”), (ii) to a relevant person, or any person pursuant to Section 275(1A), and in accordance with the conditions, specified in Section 275 of the SFA or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA.

Where the Notes are subscribed or purchased under Section 275 by a relevant person which is: (a) a corporation (which is not an accredited investor (as defined in Section 4A of the SFA)) the sole business of which is to hold investments and the entire share capital of which is owned by one or more individuals, each of whom is an accredited investor; or (b) a trust (where the trustee is not an accredited investor) whose sole purpose is to hold investments and each beneficiary is an accredited investor, securities (as defined in Section 239(1) of the SFA) of that corporation or the beneficiaries’ rights and interest in that trust shall not be transferable for 6 months after that corporation or that trust has acquired the Notes under Section 275 except: (1) to an institutional investor or to a relevant person defined in Section 275(2) of the SFA, or any person pursuant to Section 275(1A) or Section 276(4)(i)(B) of the SFA; (2) where no consideration is or will be given for the transfer; or (3) where the transfer is by operation of law.

Singapore Securities and Futures Act Product Classification—Solely for the purposes of its obligations pursuant to sections 309B(1)(a) and 309B(1)(c) of the SFA, the Company has determined, and hereby notifies all relevant persons (as defined in Section 309A of the SFA) that the Notes are “prescribed capital markets products” (as defined in the Securities and Futures (Capital Markets Products) Regulations 2018) and Excluded Investment Products (as defined in MAS Notice SFA 04-N12: Notice on the Sale of Investment Products and MAS Notice FAA-N16: Notice on Recommendations on Investment Products).

Notice to Prospective Investors in Japan

The Notes have not been and will not be registered under the Financial Instruments and Exchange Law of Japan (the Financial Instruments and Exchange Law) and each underwriter has agreed that it will not offer or sell any Notes, directly or indirectly, in Japan or to, or for the benefit of, any resident of Japan (which term as used herein means any person resident in Japan, including any corporation or other entity organized under the laws of Japan), or to others for re-offering or resale, directly or indirectly, in Japan or to a resident of Japan, except pursuant to an exemption from the registration requirements of, and otherwise in compliance with, the Financial Instruments and Exchange Law and any other applicable laws, regulations and ministerial guidelines of Japan.

Notice to Prospective Investors in Switzerland

The Notes may not be publicly offered in Switzerland and will not be listed on the SIX Swiss Exchange (“SIX”) or on any other stock exchange or regulated trading facility in Switzerland. This prospectus supplement and the accompanying prospectus do not constitute a prospectus within the meaning of, and have been prepared without regard to the disclosure

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standards for issuance prospectuses under art. 652a or art. 1156 of the Swiss Code of Obligations or the disclosure standards for listing prospectuses under art. 27 ff. of the SIX Listing Rules or the listing rules of any other stock exchange or regulated trading facility in Switzerland. Each underwriter has represented and agreed not to publicly distribute or otherwise make publicly available in Switzerland this prospectus supplement or any other offering or marketing material relating to the Notes.

Neither this prospectus supplement nor any other offering or marketing material relating to the offering, to us or the Notes have been or will be filed with or approved by any Swiss regulatory authority. In particular, this prospectus supplement will not be filed with, and the offer of the Notes will not be supervised by, the Swiss Financial Market Supervisory Authority, and the offer of the Notes has not been and will not be authorized under the Swiss Federal Act on Collective Investment Schemes (which we refer to as the CISA). The investor protection afforded to acquirers of interests in collective investment schemes under the CISA does not extend to acquirers of the Notes.

Conflicts of Interest

Certain of the underwriters or their affiliates may hold a portion of the indebtedness that the Company intends to repay using a portion of the net proceeds from the sale of the Notes. It is possible that one or more of the underwriters or their affiliates could receive 5% or more of the net proceeds from the sale of the Notes, and, in that case, such underwriter would be deemed to have a “conflict of interest” within the meaning of the Financial Industry Regulatory Authority, Inc. (“FINRA”) Rule 5121. In the event of any such conflict of interest, such underwriter would be required to conduct the distribution of the Notes in accordance with FINRA Rule 5121. If the distribution is conducted in accordance with FINRA Rule 5121, such underwriter would not be permitted to confirm a sale of a Note in this offering to an account over which it exercises discretionary authority without the prior specific written approval of the account holder. See the “Use of Proceeds” section of this prospectus supplement for more information.

LEGAL MATTERS

Certain legal matters with respect to this offering of the Notes will be passed on for us by Thomas G. Berkemeyer, Esq., Associate General Counsel of American Electric Power Service Corporation, one of our affiliates, David C. House, Esq. or William E. Johnson, Esq., each Senior Counsel of American Electric Power Service Corporation. Certain legal matters with respect to the offering of the Notes will be passed on for the underwriters by Hunton Andrews Kurth LLP, New York, New York. From time to time, Hunton Andrews Kurth LLP acts as counsel to our affiliates for some matters.

EXPERTS

The financial statements as of December 31, 2017 and for the year ended December 31, 2017 and the related financial statement schedules and management’s assessment of the effectiveness of internal control over financial reporting (which is included in Management’s Report on Internal Control over Financial Reporting) as of December 31, 2017 incorporated in

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this Prospectus Supplement by reference to the Annual Report on Form 10-K for the year ended December 31, 2017 have been so incorporated in reliance on the report of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

The consolidated financial statements as of December 31, 2016 and for each of the two years ended December 31, 2016 and December 31, 2015 and the financial statement schedules incorporated by reference in the Prospectus to which this Prospectus Supplement relates from the American Electric Power Company, Inc. Annual Report on Form 10-K for the year ended December 31, 2017, have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their reports which are incorporated herein by reference. Such consolidated financial statements and financial statement schedules have been so incorporated in reliance upon the reports of such firm given upon their authority as experts in accounting and auditing.

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PROSPECTUS

AMERICAN ELECTRIC POWER COMPANY, INC.

1 RIVERSIDE PLAZA

COLUMBUS, OHIO 43215

(614) 716-1000

SENIOR NOTES

COMMON STOCK

JUNIOR SUBORDINATED DEBENTURES

STOCK PURCHASE CONTRACTS

STOCK PURCHASE UNITS

TERMS OF SALE

This prospectus contains summaries of the general terms of the securities. You will find the specific terms of these securities, and the manner in which they are being offered, in supplements to this prospectus. You should read this prospectus and the available prospectus supplement carefully before you invest.

The common stock of American Electric Power Company, Inc. is listed on the New York Stock Exchange under the symbol “AEP”. The last reported sale of the common stock on the New York Stock Exchange on December 12, 2017 was $76.02 per share.

In this prospectus, unless the context indicates otherwise, the words “we”, “ours” and “us” refer to American Electric Power Company, Inc. and its consolidated subsidiaries.

INVESTING IN THESE SECURITIES INVOLVES RISKS. SEE THE SECTION ENTITLED “RISK FACTORS” BEGINNING ON PAGE 2 FOR MORE INFORMATION.

The securities have not been approved or disapproved by the Securities and Exchange Commission or any state securities commission, nor have these organizations determined that this prospectus is accurate or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is December 14, 2017.

THE COMPANY

We are a public utility holding company that owns, directly or indirectly, all of the outstanding common stock of our domestic electric utility subsidiaries and varying percentages of other subsidiaries. Substantially all of our operating revenues derive from the furnishing of electric service. We were incorporated under the laws of New York in 1906 and reorganized in 1925. Our principal executive offices are located at 1 Riverside Plaza, Columbus, Ohio 43215, and our telephone number is (614) 716-1000.

We own, directly or indirectly, all the outstanding common stock of the following operating public utility companies: AEP Texas Inc., Appalachian Power Company, Indiana Michigan Power Company, Kentucky Power Company, Kingsport Power Company, Ohio Power Company, Public Service Company of Oklahoma, Southwestern Electric Power Company and Wheeling Power Company. These operating public utility companies supply electric service in portions of Arkansas, Indiana, Kentucky, Louisiana, Michigan, Ohio, Oklahoma, Tennessee, Texas, Virginia and West Virginia. We also own all of the membership interests of AEP Transmission Holding Company, LLC, a holding company for our transmission operation joint ventures and for seven transmission-only electric utilities, each of which is geographically aligned with our utility operations.

PROSPECTUS SUPPLEMENTS

We will provide information to you about the securities in up to three separate documents that progressively provide more detail: (a) this prospectus provides general information some of which may not apply to your securities, (b) the accompanying prospectus supplement provides more specific terms of your securities, and (c) the pricing supplement, if any, provides the final terms of your securities. It is important for you to consider the information contained in this prospectus, the prospectus supplement, and the pricing supplement, if any, in making your investment decision.

RISK FACTORS

Investing in our securities involves risk. Please see the risk factors described in our most recent Annual Report on Form 10-K and all subsequent Quarterly Reports on Form 10-Q, which are incorporated by reference in this prospectus. Before making an investment decision, you should carefully consider these risks as well as other information contained or incorporated by reference in this prospectus. The risks and uncertainties described are those presently known to us.

WHERE YOU CAN FIND MORE INFORMATION

This prospectus is part of a registration statement we filed with the Securities and Exchange Commission (“SEC”). We also file annual, quarterly and current reports and other information with the SEC. You may read and copy any document we file at the SEC’s Public Reference Room at 100 F Street N.E., Room 1580, Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the Public Reference Room. You may also examine our SEC filings through the SEC’s website at http://www.sec.gov.

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The SEC allows us to “incorporate by reference” the information we file with them, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus, and later information that we file with the SEC will automatically update and supersede this information. We incorporate by reference the documents listed below and any future filings made with the SEC under Sections 13(a), 13(c), 14, or 15(d) of the Securities Exchange Act of 1934 (including any documents filed after the date of the initial registration statement and prior to its effectiveness) until we sell all the securities.

You may request a copy of these filings, at no cost, by writing or telephoning us at the following address:

Investor Relations

American Electric Power Service Corporation

1 Riverside Plaza

Columbus, Ohio 43215

614-716-1000

You should rely only on the information incorporated by reference or provided in this prospectus or any supplement to this prospectus and in any written communication from us or any underwriters specifying the final terms of the particular offering. We have not authorized anyone else to provide you with different information. We are not making an offer of these securities in any state where the offer is not permitted. You should not assume that the information in this prospectus or any supplement to this prospectus is accurate as of any date other than the date on the front of those documents.

RATIO OF EARNINGS TO FIXED CHARGES

The Ratio of Earnings to Fixed Charges for each of the periods indicated is as follows:

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The Ratio of Earnings to Fixed Charges for the nine-months ended September 30, 2017 was 3.96. For current information on the Ratio of Earnings to Fixed Charges, please see our most recent Form 10-K and Form 10-Q. See Where You Can Find More Information on page 2.

USE OF PROCEEDS

Unless otherwise stated in a prospectus supplement, the net proceeds from the sale of any of the offered securities will be used for general corporate purposes relating to our business. These purposes may include redeeming or repurchasing outstanding debt, replenishing working capital, and financing our subsidiaries’ ongoing construction and maintenance programs. If we do not use the net proceeds immediately, we will temporarily invest them in short-term, interest-bearing obligations. At December 12, 2017, we had no short-term debt outstanding.

The prospectus supplement of a particular offering of securities will identify the use of proceeds for the offering.

DESCRIPTION OF THE SENIOR NOTES

General

We will issue the Senior Notes directly to the public, to a trust or as part of a Stock Purchase Unit, under an Indenture dated May 1, 2001 (as previously supplemented and amended, the “Indenture”) between us and The Bank of New York Mellon Trust Company, N.A. (as successor to The Bank of New York), as trustee (the “Trustee”). This prospectus briefly outlines some provisions of the Indenture. If you would like more information on these provisions, you should review the Indenture and any supplemental indentures or company orders that we have filed or will file with the SEC. See Where You Can Find More Information on page 2 on how to locate these documents. You may also review these documents at the Trustee’s offices at 2 North LaSalle Street, Chicago, Illinois.

The Indenture does not limit the amount of Senior Notes that may be issued. The Indenture permits us to issue Senior Notes in one or more series or tranches upon the approval of our board of directors and as described in one or more company orders or supplemental indentures. Each series of Senior Notes may differ as to their terms. The Indenture also gives us the ability to reopen a previous issue of a series of Senior Notes and issue additional Senior Notes of such series.

Because we are a holding company, the claims of creditors of our subsidiaries will have a priority over our equity rights and the rights of our creditors (including the holders of the Senior Notes) to participate in the assets of the subsidiary upon the subsidiary’s liquidation.

The Senior Notes are unsecured and will rank equally with all our unsecured unsubordinated debt. For current information on our debt outstanding see our most recent Form 10-K and 10-Q. See Where You Can Find More Information.

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A pricing or prospectus supplement will include the final terms for each Senior Note. If we decide to list upon issuance any Senior Note or Senior Notes on a securities exchange, a pricing or prospectus supplement will identify the exchange and state when we expect trading could begin. The following terms of the Senior Notes that we may sell at one or more times will be established in the applicable pricing or prospectus supplement:

The Senior Notes will be denominated in U.S. dollars and we will pay principal and interest in U.S. dollars. Unless an applicable pricing or prospectus supplement states otherwise, the Senior Notes will not be subject to any conversion, amortization, or sinking fund. We expect that the Senior Notes issued to the public will be “book-entry,” represented by a permanent global Senior Note registered in the name of Cede & Co., The Depository Trust Company’s partnership nominee or such other name as may be requested by an authorized representative of DTC. We reserve the right, however, to issue Senior Note certificates registered in the name of the Senior Noteholders.

In the discussion that follows, whenever we talk about paying principal on the Senior Notes, we mean at maturity or redemption. Also, in discussing the time for notices and how the different interest rates are calculated, all times are New York City time and all references to New York mean The City of New York, unless otherwise noted.

The Indenture does not protect holders of the Senior Notes if we engage in a highly leveraged transaction.

The following terms may apply to each Senior Note as specified in the applicable pricing or prospectus supplement and the Senior Note:

Redemptions

If we issue redeemable Senior Notes, we may redeem such Senior Notes at our option unless an applicable pricing or prospectus supplement states otherwise. The pricing or prospectus supplement will state the terms of redemption. We may redeem Senior Notes in whole or in part by delivering written notice to the Senior Noteholders no more than 60, and not less than 30, days prior to redemption. If we do not redeem all the Senior Notes of a series at

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one time, DTC (as defined herein), in the case of Senior Notes represented by a global security, will select the particular Senior Notes or portions thereof for redemption from the outstanding Senior Notes not previously redeemed in accordance with applicable procedures of DTC. If Senior Note certificates are outstanding, the Trustee selects the Senior Notes to be redeemed by lot or in such other manner it determines to be fair.

Remarketed Notes

If we issue Senior Notes with remarketing features, an applicable pricing or prospectus supplement will describe the terms for the Senior Notes including: interest rate, remarketing provisions, our right to purchase or redeem Senior Notes, the holders’ right to tender Senior Notes, and any other provisions.

Note Certificates-Registration, Transfer, and Payment of Interest and Principal

Unless otherwise indicated in the applicable prospectus supplement, each series of Senior Notes issued to the public will be issued initially in the form of one or more global notes, in registered form, without coupons, as described under Book-Entry System. However, if we issue Senior Note certificates, they will be registered in the name of the Senior Noteholder. The Senior Notes may be transferred or exchanged, pursuant to administrative procedures in the Indenture, without the payment of any service charge (other than any tax or other governmental charge) by contacting the paying agent. Payments to public holders of Senior Note certificates will be made by check or by wire transfer to an account located in the United States maintained by the person entitled thereto as specified in the security register.

Original Issue Discount

We may issue the Senior Notes at an original issue discount, bearing no interest or bearing interest at a rate that, at the time of issuance, is below market rate, to be sold at a substantial discount below their stated principal amount. Generally speaking, if the Senior Notes are issued at an original issue discount and there is an event of default or acceleration of their maturity, holders will receive an amount less than their principal amount. Tax and other special considerations applicable to original issue discount debt will be described in the prospectus supplement in which we offer those Senior Notes.

Interest Rate

The interest rate on the Senior Notes will either be fixed or floating. The interest paid will include interest accrued to, but excluding, the date of maturity or redemption. Interest is generally payable to the person in whose name the Senior Note is registered at the close of business on the record date before each interest payment date. Interest payable at maturity or redemption, however, will be payable to the person to whom principal is payable.

If we issue a Senior Note after a record date but on or prior to the related interest payment date, we will pay the first interest payment on the interest payment date after the next record date. We will pay interest payments by check or wire transfer, at our option.

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Fixed Rate Senior Notes

A pricing or prospectus supplement will designate the record dates, payment dates, our ability to defer interest payments and the fixed rate of interest payable on a Senior Note. We will pay interest quarterly or semi-annually, and upon maturity or redemption. Unless an applicable pricing or prospectus supplement states otherwise, if any payment date falls on a day that is not a business day, we will pay interest on the next business day and no additional interest will be paid. Interest payments will be the amount of interest accrued to, but excluding, each payment date. Interest will be computed using a 360-day year of twelve 30-day months.

Floating Rate Notes

Each floating rate Senior Note will have an interest rate formula. The applicable pricing or prospectus supplement will state the initial interest rate or interest rate formula on each Senior Note effective until the first interest reset date. The applicable pricing or prospectus supplement will state the method and dates on which the interest rate will be determined, reset and paid.

Events of Default

The following are events of default under the Indenture with respect to any series of Senior Notes, unless we state otherwise in the applicable prospectus supplement:

An event of default for a particular series of Senior Notes does not necessarily mean that an event of default has occurred for any other series of Senior Notes issued and outstanding under the Indenture. If an event of default occurs and continues, the Trustee or the holders of at least 33% of the principal amount of the Senior Notes of the series affected may require us to repay the entire principal of the Senior Notes of such series immediately (“Repayment Acceleration”). In most instances, the holders of at least a majority in aggregate principal amount of the Senior Notes of the affected series may rescind a previously triggered Repayment Acceleration. However, if we cause an event of default because we have failed to pay (unaccelerated) principal, premium, if any, or interest, Repayment Acceleration may be rescinded only if we have first cured our default by depositing with the Trustee enough money to pay all (unaccelerated) past due amounts and penalties, if any.

Subject to certain exceptions, the Trustee must within 90 days after a default occurs, notify the holders of the Senior Notes of the series of default unless such default has been cured

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or waived. We are required to file an annual certificate with the Trustee, signed by an officer, concerning any default by us under any provisions of the Indenture.

Subject to the provisions of the Indenture relating to its duties in case of default, the Trustee shall be under no obligation to exercise any of its rights or powers under the Indenture at the request, order or direction of any holders unless such holders offer the Trustee reasonable indemnity. Subject to the provisions for indemnification, the holders of a majority in principal amount of the Senior Notes of any series may direct the time, method and place of conducting any proceedings for any remedy available to, or exercising any trust or power conferred on, the Trustee with respect to such Senior Notes.

Modification of Indenture

Under the Indenture, our rights and obligations and the rights of the holders of any Senior Notes may be changed. Any change affecting the rights of the holders of any series of Senior Notes requires the consent of the holders of not less than a majority in aggregate principal amount of the outstanding Senior Notes of all series affected by the change, voting as one class. However, we cannot change the terms of payment of principal or interest, or reduce the percentage required for changes or a waiver of default, unless the holder consents. We may issue additional series of Senior Notes and take other action that does not affect the rights of holders of any series by executing supplemental indentures without the consent of any Senior Noteholders.

Consolidation, Merger or Sale

We may merge or consolidate with any entity or sell substantially all of our assets as an entirety as long as the successor or purchaser (i) is organized and existing under the laws of the United States, any state thereof or the District of Columbia and (ii) expressly assumes the payment of principal, premium, if any, and interest on the Senior Notes.

Legal Defeasance

We will be discharged from our obligations on the Senior Notes of any series at any time if:

If this happens, the Senior Noteholders of the series will not be entitled to the benefits of the Indenture except for registration of transfer and exchange of Senior Notes and replacement of lost, stolen or mutilated Senior Notes.

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Covenant Defeasance

We will be discharged from our obligations under any restrictive covenant applicable to the Senior Notes of a particular series if we perform both actions described above. See Legal Defeasance. If this happens, any later breach of that particular restrictive covenant will not result in Repayment Acceleration. If we cause an event of default apart from breaching that restrictive covenant, there may not be sufficient money or government obligations on deposit with the Trustee to pay all amounts due on the Senior Notes of that series. In that instance, we would remain liable for such amounts.

Governing Law

The Indenture and Senior Notes of all series will be governed by the laws of the State of New York.

Concerning the Trustee

We and our affiliates use or will use some of the banking services of the Trustee in the normal course of business. The Trustee is also the Subordinated Indenture Trustee under the Subordinated Indenture relating to the Junior Subordinated Debentures.

DESCRIPTION OF COMMON STOCK

Our authorized capital stock currently consists of 600,000,000 shares of common stock, par value $6.50 per share. 492,002,351 shares of our common stock were issued and outstanding as of December 12, 2017. Our common stock, including the common stock offered in this prospectus once issued, is listed on the New York Stock Exchange. Computershare Trust Company, N.A., P.O. Box 43081, Providence, Rhode Island 02940-3081, is the transfer agent and registrar for our common stock.

Dividend Rights

The holders of our common stock are entitled to receive the dividends declared by our board of directors provided funds are legally available for such dividends. Our income derives from our common stock equity in the earnings of our subsidiaries. Various financing arrangements and regulatory requirements may impose certain restrictions on the ability of our subsidiaries to transfer funds to us in the form of cash dividends, loans or advances.

Voting Rights

The holders of our common stock are entitled to one vote for each share of common stock held.

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Pre-emptive Rights

The holders of our common stock generally do not have the right to subscribe for or purchase any part of any new or additional issue of our common stock. If, however, our board of directors determines to issue and sell any common stock solely for money and not by (1) a public offering, (2) an offering to or through underwriters or dealers who have agreed to promptly make a public offering, or (3) any other offering which the holders of a majority of our outstanding common stock have authorized; then such common stock must first be offered pro rata to our existing shareholders on terms no less favorable than those offered to persons other than our existing shareholders.

Rights Upon Liquidation

If we are liquidated, holders of our common stock will be entitled to receive pro rata all assets available for distribution to our shareholders after payment of our liabilities, including liquidation expenses.

Restrictions on Dealing with Existing Shareholders

We are subject to Section 513 of New York’s Business Corporation Law, which provides that no domestic corporation may purchase or agree to purchase more than 10% of its stock from a shareholder who has held the shares for less than two years at any price that is higher than the market price unless the transaction is approved by both the corporation’s board of directors and a majority of the votes of all outstanding shares entitled to vote thereon at a meeting of shareholders, unless the certificate of incorporation requires a greater percentage of the votes of the outstanding shares to approve or the corporation offers to purchase shares from all the holders on the same terms. Our certificate of incorporation does not currently provide for a higher percentage.

DESCRIPTION OF THE JUNIOR SUBORDINATED DEBENTURES

General

We will issue the Junior Subordinated Debentures directly to the public, to a trust or as part of a Stock Purchase Unit under the Junior Subordinated Indenture dated March 1, 2008 (the “Subordinated Indenture”) between us and The Bank of New York Mellon Trust Company, N.A. (as successor to The Bank of New York), as the trustee (the “Subordinated Indenture Trustee”). This prospectus briefly outlines some provisions of the Subordinated Indenture. If you would like more information on these provisions, you should review the Subordinated Indenture and any supplemental indentures or company orders that we will file with the SEC. See Where You Can Find More Information on how to locate these documents. You may also review these documents at the Subordinated Indenture Trustee’s offices at 2 North LaSalle Street, Chicago, Illinois.

The Junior Subordinated Debentures are unsecured obligations and are junior in right of payment to “Senior Indebtedness”. You may find a description of the subordination provisions

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of the Junior Subordinated Debentures, including a description of Senior Indebtedness under Subordination.

Because we are a holding company, the claims of creditors of our subsidiaries will have a priority over our equity rights and the rights of our creditors (including the holders of the Junior Subordinated Debentures) to participate in the assets of the subsidiary upon the subsidiary’s liquidation.

The Subordinated Indenture does not limit the amount of Junior Subordinated Debentures that we may issue under it. We may issue Junior Subordinated Debentures from time to time under the Subordinated Indenture in one or more series by entering into supplemental indentures or by our Board of Directors or a duly authorized committee authorizing the issuance. The Subordinated Indenture also gives us the ability to reopen a previous issue of a series of Junior Subordinated Debentures and issue additional Junior Subordinated Debentures of such series.

A pricing or prospectus supplement will include the final terms for each Junior Subordinated Debenture. If we decide to list upon issuance any Junior Subordinated Debenture or Junior Subordinated Debentures on a securities exchange, a pricing or prospectus supplement will identify the exchange and state when we expect trading could begin. The following terms of the Junior Subordinated Debentures that we may sell at one or more times will be established in a prospectus supplement:

The Subordinated Indenture does not protect the holders of Junior Subordinated Debentures if we engage in a highly leveraged transaction.

Redemption

Provisions relating to the redemption of Junior Subordinated Debentures will be set forth in the applicable prospectus supplement. Unless we state otherwise in the applicable prospectus supplement, we may redeem Junior Subordinated Debentures only upon notice mailed at least 30 but not more than 60 days before the date fixed for redemption. If we do not redeem all the Junior Subordinated Debentures of a series at one time, DTC, in the case of Junior Subordinated

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Debentures represented by a global security, will select the particular Junior Subordinated Debentures or portions thereof for redemption from the outstanding Junior Subordinated Debentures not previously redeemed in accordance with applicable procedures of DTC. If Junior Subordinated Debenture certificates are outstanding, the Subordinated Indenture Trustee selects the Junior Subordinated Debentures to be redeemed by lot or in such other manner it determines to be fair.

Junior Subordinated Debenture Certificates-Registration, Transfer, and Payment of Interest and Principal

Unless otherwise indicated in the applicable prospectus supplement, each series of Junior Subordinated Debentures issued to the public initially will be in the form of one or more global Junior Subordinated Debentures, in registered form, without coupons, as described under Book-Entry System. However, if we issue Junior Subordinated Debenture certificates, they will be registered in the name of the Junior Subordinated Debentureholder. The Junior Subordinated Debentures may be transferred or exchanged, pursuant to administrative procedures in the Subordinated Indenture, without the payment of any service charge (other than any tax or other governmental charge) by contacting the paying agent. Payments to public holders of Junior Subordinated Debenture certificates will be made by check or by wire transfer to an account located in the United States maintained by the person entitled thereto as specified in the security register.

Original Issue Discount

We may issue the Junior Subordinated Debentures at an original issue discount, bearing no interest or bearing interest at a rate that, at the time of issuance, is below market rate, to be sold at a substantial discount below their stated principal amount. Generally speaking, if the Junior Subordinated Debentures are issued at an original issue discount and there is an event of default or acceleration of their maturity, holders will receive an amount less than their principal amount. Tax and other special considerations applicable to original issue discount debt will be described in the prospectus supplement in which we offer those Junior Subordinated Debentures.

Interest Rate

The interest rate on the Junior Subordinated Debentures will either be fixed or floating. The interest paid will include interest accrued to, but excluding, the date of maturity or redemption. Interest is generally payable to the person in whose name the Junior Subordinated Debenture is registered at the close of business on the record date before each interest payment date. Interest payable at maturity or redemption, however, will be payable to the person to whom principal is payable.

If we issue a Junior Subordinated Debenture after a record date but on or prior to the related interest payment date, we will pay the first interest payment on the interest payment date after the next record date. We will pay interest payments by check or wire transfer, at our option.

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Fixed Rate Junior Subordinated Debentures

A pricing or prospectus supplement will designate the record dates, payment dates, our ability to defer interest payments and the fixed rate of interest payable on a Junior Subordinated Debenture. We will pay interest quarterly or semi-annually, and upon maturity or redemption. Unless an applicable pricing or prospectus supplement states otherwise, if any payment date falls on a day that is not a business day, we will pay interest on the next business day and no additional interest will be paid. Interest payments will be the amount of interest accrued to, but excluding, each payment date. Interest will be computed using a 360-day year of twelve 30-day months.

Floating Rate Junior Subordinated Debentures

Each floating rate Junior Subordinated Debenture will have an interest rate formula. The applicable pricing or prospectus supplement will state the initial interest rate or interest rate formula on each Junior Subordinated Debenture effective until the first interest reset date. The applicable pricing or prospectus supplement will state the method and dates on which the interest rate will be determined, reset and paid.

Events of Default

The following are events of default under the Subordinated Indenture with respect to any series of Junior Subordinated Debentures, unless we state otherwise in the applicable prospectus supplement:

An event of default for a particular series of Junior Subordinated Debentures does not necessarily mean that an event of default has occurred for any other series of Junior Subordinated Debentures issued under the Subordinated Indenture. If an event of default occurs and continues, the Subordinated Indenture Trustee or the holders of at least 33% of the principal amount of the Junior Subordinated Debentures of the series affected may require us to repay the entire principal of the Junior Subordinated Debentures of such series immediately (“Repayment Acceleration”). In most instances, the holders of at least a majority in aggregate principal amount of the Junior Subordinated Debentures of the affected series may rescind a previously triggered Repayment Acceleration. However, if we cause an event of default because we have failed to pay (unaccelerated) principal, premium, if any, or interest, Repayment Acceleration may be rescinded only if we have first cured our default by depositing with the Subordinated

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Indenture Trustee enough money to pay all (unaccelerated) past due amounts and penalties, if any.

Subject to certain exceptions, the Subordinated Indenture Trustee must within 90 days after a default occurs, notify the holders of the Junior Subordinated Debentures of the series of default unless such default has been cured or waived. We are required to file an annual certificate with the Subordinated Indenture Trustee, signed by an officer, concerning any default by us under any provisions of the Subordinated Indenture.

Subject to the provisions of the Subordinated Indenture relating to its duties in case of default, the Subordinated Indenture Trustee shall be under no obligation to exercise any of its rights or powers under the Subordinated Indenture at the request, order or direction of any holders unless such holders offer the Subordinated Indenture Trustee reasonable indemnity. Subject to the provisions for indemnification, the holders of a majority in principal amount of the Junior Subordinated Debentures of any series may direct the time, method and place of conducting any proceedings for any remedy available to, or exercising any trust or power conferred on, the Subordinated Indenture Trustee with respect to such Junior Subordinated Debentures.

Modification of Subordinated Indenture

Under the Subordinated Indenture, our rights and obligations and the rights of the holders of any Junior Subordinated Debentures may be changed. Any change affecting the rights of the holders of any series of Junior Subordinated Debentures requires the consent of the holders of not less than a majority in aggregate principal amount of the outstanding Junior Subordinated Debentures of all series affected by the change, voting as one class. However, we cannot change the terms of payment of principal or interest, or reduce the percentage required for changes or a waiver of default, unless the holder consents. We may issue additional series of Junior Subordinated Debentures and take other action that does not affect the rights of holders of any series by executing supplemental indentures without the consent of any debentureholders.

Consolidation, Merger or Sale

We may merge or consolidate with any entity or sell substantially all of our assets as an entirety as long as the successor or purchaser (i) is organized and existing under the laws of the United States, any state thereof or the District of Columbia and (ii) expressly assumes the payment of principal, premium, if any, and interest on the Junior Subordinated Debentures.

Legal Defeasance

We will be discharged from our obligations on the Junior Subordinated Debentures of any series at any time if:

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If this happens, the debentureholders of the series will no longer be entitled to the benefits of the Subordinated Indenture except for registration of transfer and exchange of Junior Subordinated Debentures and replacement of lost, stolen or mutilated Junior Subordinated Debentures.

Covenant Defeasance

We will be discharged from our obligations under any restrictive covenant applicable to the Junior Subordinated Debentures of a particular series if we perform both actions described above. See Legal Defeasance. If this happens, any later breach of that particular restrictive covenant will not result in Repayment Acceleration. If we cause an event of default apart from breaching that restrictive covenant, there may not be sufficient money or government obligations on deposit with the Subordinated Indenture Trustee to pay all amounts due on the Junior Subordinated Debentures of that series. In that instance, we would remain liable for such amounts.

Junior Subordinated Debentures issued to a trust will not be subject to covenant defeasance.

Subordination

Each series of Junior Subordinated Debentures will be subordinate and junior in right of payment, to the extent set forth in the Subordinated Indenture, to all Senior Indebtedness as defined below. If:

then the holders of Senior Indebtedness generally will have the right to receive payment, in the case of the first instance, of all amounts due or to become due upon that Senior Indebtedness, and, in the case of the second and third instances, of all amounts due on that Senior Indebtedness, or we will make provision for those payments, before the holders of any Junior Subordinated Debentures have the right to receive any payments of principal or interest on their Junior Subordinated Debentures.

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“Senior Indebtedness” means, with respect to any series of Junior Subordinated Debentures, the principal, premium, interest and any other payment in respect of any of the following:

Any such indebtedness, renewal, extension or refunding, however, will not be Senior Indebtedness if the instrument creating or evidencing it or the assumption or Guarantee of it provides that it is not superior in right of payment to or is equal in right of payment with those Junior Subordinated Debentures. Senior Indebtedness will be entitled to the benefits of the subordination provisions in the Subordinated Indenture irrespective of the amendment, modification or waiver of any term of the Senior Indebtedness.

The Subordinated Indenture does not limit the amount of Senior Indebtedness that we may issue. As of December 1, 2017, our Senior Indebtedness totaled approximately

$1.85 billion.

Governing Law

The Subordinated Indenture and Junior Subordinated Debentures of all series are governed by the laws of the State of New York.

Concerning the Trustee

We and our affiliates use or will use some of the banking services of the Subordinated Indenture Trustee in the normal course of business. The Subordinated Trustee is also the Trustee under the Indenture relating to the Senior Notes.

DESCRIPTION OF THE STOCK PURCHASE CONTRACTS AND THE STOCK PURCHASE UNITS

We may issue Stock Purchase Contracts representing contracts obligating holders to purchase from us and we may sell to the holders, a specified number of shares of common stock (or a range of numbers of shares pursuant to a predetermined formula) at a future date or dates. The price per share of common stock may be fixed at the time the Stock Purchase Contracts are issued or may be determined by reference to a specific formula set forth in the Stock Purchase Contracts.

The Stock Purchase Contracts may be issued separately or as a part of units, often known as Stock Purchase Units, consisting of a Stock Purchase Contract and either Debt Securities or

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debt obligations of third parties, including U.S. Treasury securities, securing the holder’s obligations to purchase the common stock under the Stock Purchase Contracts.

The Stock Purchase Contracts may require us to make periodic payments to the holders of the Stock Purchase Units or vice versa, and such payments may be unsecured or prefunded on some basis. The Stock Purchase Contracts may require holders to secure their obligations in a specified manner and in certain circumstances we may deliver newly issued prepaid Stock Purchase Contracts, often known as prepaid securities, upon release to a holder of any collateral securing such holder’s obligations under the original Stock Purchase Contract.

The applicable prospectus supplement will describe the terms of any Stock Purchase Contracts or Stock Purchase Units and, if applicable, prepaid securities. The description in the applicable prospectus supplement will not necessarily contain all of information that you may find useful. For more information, you should review the Stock Purchase Contracts, the collateral arrangements and depositary arrangements, if applicable, relating to such Stock Purchase Contracts or Stock Purchase Units and, if applicable, the prepaid securities and the document pursuant to which the prepaid securities will be issued. These documents will be filed with the SEC promptly after the offering of such Stock Purchase Contracts or Stock Purchase Units and, if applicable, prepaid securities.

BOOK-ENTRY SYSTEM

Unless otherwise stated in a prospectus supplement, book-entry only securities of a series will be issued in the form of a global security that the Trustee will deposit with the Depository Trust Company (“DTC”), New York, New York. This means that we will not issue security certificates to each holder. One or more global securities will be issued to Cede & Co. (DTC’s partnership nominee) or such other name as may be requested by an authorized representative of DTC who will keep a computerized record of its participants (for example, your broker) whose clients have purchased the securities. The participant will then keep a record of its clients who purchased the securities. Unless it is exchanged in whole or in part for a certificate, a global security may not be transferred, except that DTC, its nominees, and their successors may transfer a global security as a whole to one another.

Beneficial interests in global securities will be shown on, and transfers of global securities will be made only through, records maintained by DTC and its participants.

DTC, the world’s largest securities depository, is a limited-purpose trust company organized under the New York Banking Law, a “banking organization” within the meaning of the New York Banking Law, a member of the Federal Reserve System, a “clearing corporation” within the meaning of the New York Uniform Commercial Code, and a “clearing agency” registered pursuant to the provisions of Section 17A of the Securities Exchange Act of 1934, as amended. DTC holds and provides asset servicing for over 3.5 million issues of U.S. and non-U.S. equity issues, corporate and municipal debt issues, and money market instruments (from over 100 countries) that DTC’s participants (“Direct Participants”) deposit with DTC. DTC also facilitates the post-trade settlement among Direct Participants of sales and other securities transactions in deposited securities, through electronic computerized book-entry transfers and pledges between

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Direct Participants’ accounts. This eliminates the need for physical movement of securities certificates. Direct Participants include both U.S. and non-U.S. securities brokers and dealers, banks, trust companies, clearing corporations, and certain other organizations. DTC is a wholly-owned subsidiary of The Depository Trust & Clearing Corporation (“DTCC”). DTCC is the holding company for DTC, National Securities Clearing Corporation and Fixed Income Clearing Corporation, all of which are registered clearing agencies. DTCC is owned by the users of its regulated subsidiaries. Access to the DTC system is also available to others such as both U.S. and non-U.S. securities brokers and dealers, banks, trust companies, and clearing corporations that clear through or maintain a custodial relationship with a Direct Participant, either directly or indirectly (“Indirect Participants”). The DTC Rules applicable to its Participants are on file with the SEC. More information about DTC can be found at www.dtcc.com .

Purchases of securities under the DTC system must be made by or through Direct Participants, which will receive a credit for the securities on DTC’s records. The ownership interest of each actual purchaser of each security (“Beneficial Owner”) is in turn to be recorded on the Direct and Indirect Participants’ records. Beneficial Owners will not receive written confirmation from DTC of their purchase. Beneficial Owners are, however, expected to receive written confirmations providing details of the transaction, as well as periodic statements of their holdings, from the Direct or Indirect Participant through which the Beneficial Owner entered into the transaction. Transfers of ownership interests in the securities are to be accomplished by entries made on the books of Direct and Indirect Participants acting on behalf of Beneficial Owners. Beneficial Owners will not receive certificates representing their ownership interests in securities, except in the event that use of the book-entry system for the securities is discontinued.

To facilitate subsequent transfers, all securities deposited by Direct Participants with DTC are registered in the name of DTC’s partnership nominee, Cede & Co., or such other name as may be requested by an authorized representative of DTC. The deposit of securities with DTC and their registration in the name of Cede & Co. or such other DTC nominee do not effect any change in beneficial ownership. DTC has no knowledge of the actual Beneficial Owners of the securities; DTC’s records reflect only the identity of the Direct Participants to whose accounts such securities are credited, which may or may not be the Beneficial Owners. The Direct and Indirect Participants will remain responsible for keeping account of their holdings on behalf of their customers.

Conveyance of notices and other communications by DTC to Direct Participants, by Direct Participants to Indirect Participants, and by Direct Participants and Indirect Participants to Beneficial Owners will be governed by arrangements among them, subject to any statutory or regulatory requirements as may be in effect from time to time. Beneficial Owners of securities may wish to take certain steps to augment the transmission to them of notices of significant events with respect to the securities, such as redemptions, tenders, defaults, and proposed amendments to the securities documents. For example, Beneficial Owners of securities may wish to ascertain that the nominee holding the securities for their benefit has agreed to obtain and transmit notices to Beneficial Owners. In the alternative, Beneficial Owners may wish to provide their names and addresses to the registrar and request that copies of notices be provided directly to them.

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Redemption notices shall be sent to DTC. If less than all of the securities are being redeemed, DTC’s practice is to determine by lot the amount of the interest of each Direct Participant in such issue to be redeemed.

Neither DTC nor Cede & Co. (nor any other DTC nominee) will consent or vote with respect to the securities unless authorized by a Direct Participant in accordance with DTC’s MMI Procedures. Under its usual procedures, DTC mails an Omnibus Proxy to us as soon as possible after the record date. The Omnibus Proxy assigns Cede & Co.’s consenting or voting rights to those Direct Participants to whose accounts the securities are credited on the record date (identified in a listing attached to the Omnibus Proxy).

Payments on the securities will be made to Cede & Co., or such other nominee as may be requested by an authorized representative of DTC. DTC’s practice is to credit Direct Participants’ accounts upon DTC’s receipt of funds and corresponding detail information from us or the Trustee on the payable date in accordance with their respective holdings shown on DTC’s records. Payments by Participants to Beneficial Owners will be governed by standing instructions and customary practices, as is the case with securities held for the accounts of customers in bearer form or registered in “street name”, and will be the responsibility of such Participant and not of DTC, the Trustee or us, subject to any statutory or regulatory requirements as may be in effect from time to time. Payment of redemption proceeds and distributions to Cede & Co. (or such other nominee as may be requested by an authorized representative of DTC) is our responsibility, disbursement of such payments to Direct Participants will be the responsibility of DTC, and disbursement of such payments to the Beneficial Owners will be the responsibility of Direct and Indirect Participants.

A Beneficial Owner shall give notice to elect to have its securities purchased or tendered, through its Participant, to the Tender/Remarketing Agent, and shall effect delivery of such securities by causing the Direct Participant to transfer the Participant’s interest in the securities, on DTC’s records, to the Tender/Remarketing Agent. The requirement for physical delivery of the securities in connection with an optional tender or a mandatory purchase will be deemed satisfied when the ownership rights in the securities are transferred by Direct Participants on DTC’s records and followed by a book-entry credit of tendered securities to the Tender/Remarketing Agent’s DTC account.

DTC may discontinue providing its services as depository with respect to the securities at any time by giving reasonable notice to us. Under such circumstances, in the event that a successor depository is not obtained, security certificates are required to be printed and delivered.

We may decide to discontinue use of the system of book-entry only transfers through DTC (or a successor securities depository). In that event, security certificates will be printed and delivered to DTC.

The information in this section concerning DTC and DTC’s book-entry system has been obtained from sources that we believe to be reliable, but we take no responsibility for the accuracy thereof.

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PLAN OF DISTRIBUTION

We may sell the securities (a) through agents; (b) through underwriters or dealers; or (c) directly to one or more purchasers.

By Agents

Securities may be sold on a continuing basis through agents designated by us. The agents will agree to use their reasonable efforts to solicit purchases for the period of their appointment.

Any initial offering price and any discounts, concessions or commissions allowed or reallowed or paid to dealers may be changed from time to time.

The agents will not be obligated to make a market in the securities. We cannot predict the amount of trading or liquidity of the securities.

By Underwriters

The applicable prospectus supplement will set forth the terms under which the securities are offered, including the name or names of any underwriters, the purchase price of the securities and the proceeds to us from the sale, any underwriting discounts and other items constituting underwriters’ compensation, any initial offering price and any discounts, commissions or concessions allowed or reallowed or paid to dealers.

If underwriters are used in the sale, the underwriters will acquire the securities for their own account. The underwriters may resell the securities in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. The obligations of the underwriters to purchase the securities will be subject to certain conditions. The underwriters will be obligated to purchase all the securities offered if any are purchased. Any initial public offering price and any discounts or concessions allowed or re-allowed or paid to dealers may be changed from time to time.

The underwriters may not be obligated to make a market in the securities. We cannot predict the amount of trading or liquidity of the securities.

Direct Sales

We may also sell securities directly. In this case, no underwriters or agents would be involved.

General Information

Underwriters, dealers, and agents that participate in the distribution of the securities may be underwriters as defined in the Securities Act of 1933 (the “Act”), and any discounts or commissions received by them from us and any profit on the resale of the securities by them may be treated as underwriting discounts and commissions under the Act.

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We may have agreements with the underwriters, dealers and agents to indemnify them against certain civil liabilities, including liabilities under the Act or to contribute to payments that each underwriter, dealer or agent may be required to make in respect thereto.

Underwriters, dealers and agents may engage in transactions with, or perform services for, us or our affiliates in the ordinary course of their businesses.

LEGAL OPINIONS

Our counsel, Simpson Thacher & Bartlett LLP, New York, NY, or Thomas G. Berkemeyer, Esq., Associate General Counsel of American Electric Power Service Corporation, one of our affiliates, or David C. House, Esq. or William E. Johnson, Esq., each Senior Counsel of American Electric Power Service Corporation, will issue an opinion about the legality of the securities for us. Hunton & Williams LLP, New York, NY will issue an opinion for the agents or underwriters. From time to time, Hunton & Williams LLP acts as counsel to our affiliates for some matters.

EXPERTS

The American Electric Power Company, Inc. and subsidiary companies (the “Company”) consolidated financial statements, and the related financial statement schedules, incorporated in this prospectus by reference from the American Electric Power Company, Inc. Annual Report on Form 10-K for the year ended December 31, 2016, and the effectiveness of the Company’s internal control over financial reporting, have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their reports, which are incorporated herein by reference. Such consolidated financial statements and financial statement schedules have been so incorporated in reliance upon the reports of such firm given upon their authority as experts in accounting and auditing.

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$                 % Senior Notes, Series I, due

$                 % Senior Notes, Series J, due

AMERICAN ELECTRIC POWER COMPANY, INC.

PROSPECTUS SUPPLEMENT

Joint Book-Running Managers

November    , 2018