Filed Pursuant to Rule 424(b)(2)

Registration No. 333-215833

CALCULATION OF REGISTRATION FEE

PROSPECTUS SUPPLEMENT

(To Prospectus Dated January 31, 2017)

800,000 Shares

CenterPoint Energy, Inc.

Series A Fixed-to-Floating Rate Cumulative Redeemable

Perpetual Preferred Stock

(Liquidation Preference $1,000 per share)

We are offering 800,000 shares of our Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Stock, par value $0.01 per share (“Series A Preferred Stock”), with a liquidation preference of $1,000 per share (the “stated amount”).

Holders of Series A Preferred Stock will be entitled to receive out of any funds legally available, when, if and as declared by our board of directors (or a duly authorized committee of the board), cumulative cash dividends:

The shares of Series A Preferred Stock are perpetual and have no maturity date. The Series A Preferred Stock may be redeemed by us at our option (i) on or after September 1, 2023, from time to time and in whole or in part, at a redemption price in cash per share equal to $1,000, or (ii) following the occurrence of a Ratings Event (as defined herein), in whole, but not in part, at a redemption price in cash per share equal to $1,020, in each case out of funds legally available for such redemption and plus an amount equal to all accumulated and unpaid dividends thereon to, but excluding, the redemption date, whether or not declared.

The Series A Preferred Stock will, with respect to anticipated dividends and distributions upon the liquidation, dissolution or winding up of our affairs, rank: senior to our common stock and to each other class or series of our capital stock established after the original issue date of the Series A Preferred Stock that is expressly made subordinated to the Series A Preferred Stock as to the payment of dividends and amounts payable on a liquidation, dissolution or winding up of our affairs; on a parity with any class or series of our capital stock established after the original issue date of the Series A Preferred Stock that is not expressly made senior or subordinated to the Series A Preferred Stock as to the payment of dividends and amounts payable on a liquidation, dissolution or winding up of our affairs; junior to any class or series of our capital stock established after the original issue date of the Series A Preferred Stock that is expressly made senior to the Series A Preferred Stock as to the payment of dividends and amounts payable on a liquidation, dissolution or winding up of our affairs; junior to all of our existing and future indebtedness (including indebtedness outstanding under our credit facilities, our senior notes and our commercial paper) and other liabilities with respect to assets available to satisfy claims against us; and structurally subordinated to any existing and future indebtedness and other liabilities of our subsidiaries and capital stock of our subsidiaries held by third parties.

The Series A Preferred Stock is a new issue of securities with no established trading market. We do not intend to apply for listing of the Series A Preferred Stock on any securities exchange.

Investing in the Series A Preferred Stock involves risks. See “Risk Factors” beginning on page S-12 of this prospectus supplement and on page 5 of the accompanying prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The underwriters expect to deliver the shares of Series A Preferred Stock against payment therefor on or about August 22, 2018.

Joint Book-Running Managers

Senior Co-Managers

Co-Managers

Prospectus Supplement dated August 15, 2018

This document consists of two parts, which should be read together. The first part is this prospectus supplement, which describes the specific terms of the Series A Preferred Stock, the specific terms of this offering and supplements and updates information contained in the accompanying prospectus and the documents incorporated by reference into this prospectus supplement and the accompanying prospectus. The second part, the accompanying prospectus, provides more general information about the preferred stock and other securities that may be offered from time to time using such prospectus, some of which general information does not apply to this offering. Generally, when we refer to the prospectus, we are referring to both parts of this document combined. You should read this prospectus supplement and the accompanying prospectus together with any written communication prepared by us or on our behalf in connection with this offering together with the additional information described in this prospectus supplement under the headings “Where You Can Find More Information” and “Incorporation By Reference.”

We have not, and the underwriters have not, authorized anyone to provide any information or to make any representations other than those contained or incorporated by reference in this prospectus supplement, the accompanying prospectus and any written communication prepared by us or on our behalf. We and the underwriters take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. We are not, and the underwriters are not, making an offer to sell the Series A Preferred Stock and are not soliciting an offer to buy the Series A Preferred Stock in any jurisdiction where the offer or sale is not permitted. The information we have included in this prospectus supplement or the accompanying prospectus is accurate only as of the date of this prospectus supplement or the accompanying prospectus, as the case may be, and any information we have incorporated by reference into this prospectus supplement or the accompanying prospectus is accurate only as of the date of the document incorporated by reference. Our businesses, financial condition, results of operations and prospects may have changed since these respective dates.

Any information contained in this prospectus supplement or the accompanying prospectus or in a document incorporated by reference in this prospectus supplement or the accompanying prospectus will be deemed to be modified or superseded to the extent that a statement contained in this prospectus supplement or in any other subsequently filed document that is also incorporated by reference in this prospectus supplement modifies or supersedes that statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus supplement. See “Incorporation By Reference” in this prospectus supplement.

S-i

TABLE OF CONTENTS

Prospectus Supplement

Prospectus

We expect that delivery of the Series A Preferred Stock offered hereby will be made against payment therefor on or about August 22, 2018, which will be the fifth business day following the date of pricing of the Series A Preferred Stock (this settlement cycle being referred to as “T+5”). Under Rule 15c6-1 of the Exchange Act, trades in the secondary market generally are required to settle in two business days, unless the parties to a trade expressly agree otherwise. Accordingly, purchasers who wish to trade the Series A Preferred Stock on the initial pricing date of the Series A Preferred Stock or the next two succeeding business days will be required, by virtue of the fact that the Series A Preferred Stock initially will settle in T+5, to specify alternative settlement arrangements at the time of any such trade to prevent a failed settlement and should consult their own advisors.

S-ii

S-1

S-2

S-3

S-4

S-5

S-6

S-7

S-8

S-9

S-10

S-11

RISK FACTORS

In addition to the following information about risks, you should consider carefully the risk factors and risks identified or referenced in our Annual Report on Form 10-K for the fiscal year ended December 31, 2017 (“2017 Form 10-K”) and our Quarterly Reports on Form 10-Q for the quarterly periods ended March 31, 2018 and June 30, 2018 (“2nd Quarter 2018 Form 10-Q”), which are incorporated by reference in this prospectus supplement and the accompanying prospectus, as they may be amended, supplemented or superseded from time to time by other reports that we subsequently file with the Securities and Exchange Commission (the “SEC”), together with the other information contained or incorporated by reference in this prospectus supplement and the accompanying prospectus, before making an investment in the Series A Preferred Stock.

Risks Related to the Series A Preferred Stock

The Series A Preferred Stock represents a perpetual equity investment in CenterPoint Energy, and holders of Series A Preferred Stock should not expect us to redeem the Series A Preferred Stock on the date the Series A Preferred Stock becomes redeemable by us or on any particular date afterwards.

The Series A Preferred Stock represents a perpetual equity investment in CenterPoint Energy, has no maturity or mandatory redemption date and is not redeemable at the option of holders of Series A Preferred Stock under any circumstances. As a result, unlike our indebtedness, the Series A Preferred Stock will not give rise to a claim for payment of a principal amount at a particular date. Instead, the Series A Preferred Stock may be redeemed by us at our option (i) on or after September 1, 2023, from time to time and in whole or in part, at a redemption price in cash per share equal to $1,000, or (ii) following the occurrence of a Ratings Event, in whole, but not in part, at a redemption price in cash per share equal to $1,020, in each case out of funds legally available for such redemption and plus an amount equal to all accumulated and unpaid dividends thereon to, but excluding, the redemption date, whether or not declared. Any decision we may make at any time to redeem the Series A Preferred Stock will depend upon, among other things, our evaluation of our capital position and general market conditions at that time. In addition, the instruments governing our outstanding indebtedness or any Senior Stock may limit our ability to redeem the Series A Preferred Stock.

As a result, holders of the Series A Preferred Stock may be required to bear the financial risks of an investment in the Series A Preferred Stock for an indefinite period of time. Moreover, holders of the Series A Preferred Stock will not have any rights of conversion or exchange for other equity interests in us. The Series A Preferred Stock will rank junior to all our current and future indebtedness. The Series A Preferred Stock will also rank junior to any Senior Stock we may issue in the future with respect to assets available to satisfy claims against us.

We are a holding company with no operations or operating assets of our own. As a result, we depend on distributions from our subsidiaries and from Enable to meet our payment obligations and for the ability to pay dividends on the Series A Preferred Stock, and provisions of applicable law or contractual restrictions could limit the amount of those distributions.

We derive all of our operating income from, and hold all of our assets through, our subsidiaries, including our interests in Enable. As a result, we depend on distributions from our subsidiaries and Enable to meet our payment obligations and for our ability to declare and pay dividends, including dividends on the Series A Preferred Stock. In general, our subsidiaries are separate and distinct legal entities and have no obligation to provide us with funds for our payment obligations, whether by dividends, distributions, loans or otherwise. In addition, provisions of applicable law, such as those limiting the legal sources of dividends, limit our subsidiaries’ and Enable’s ability to make payments or other distributions to us, and our subsidiaries or Enable could agree to contractual restrictions on their ability to make distributions.

Our right to receive any assets of any subsidiary, and therefore the right of our holders of the Series A Preferred Stock to participate in those assets, will be structurally subordinated to the claims of that subsidiary’s

S-12

creditors, including trade creditors. In addition, even if we were a creditor of any subsidiary, our rights as a creditor would be effectively subordinated to any security interest in the assets of that subsidiary and any indebtedness of the subsidiary senior to that held by us.

Dividends are payable on the Series A Preferred Stock only when, as and if declared and only out of funds legally available therefor.

Unlike indebtedness, where principal and interest would customarily be payable on specified due dates, dividends on the Series A Preferred Stock are payable when, as and if declared by our board of directors (or a duly authorized committee of the board), and only out of funds legally available therefor. In addition, we may become subject to contractual restrictions on our ability to pay dividends in the future, whether under indebtedness or otherwise. Therefore, although dividends are cumulative on the Series A Preferred Stock, you cannot be certain that dividends will be paid on the Series A Preferred Stock on the dividend payment dates described herein, or at all.

The Series A Preferred Stock is equity and therefore is subordinated to our existing and future indebtedness.

The Series A Preferred Stock is subordinated to all of our existing and future indebtedness (including without limitation indebtedness outstanding under our credit facilities, our senior notes and our commercial paper) we may issue in the future with respect to assets available to satisfy claims against us. As of June 30, 2018, we, on an unconsolidated basis, had approximately $1.4 billion aggregate principal amount of indebtedness outstanding, $1.3 billion of which was unsecured and unsubordinated. Excluding subsidiaries issuing transition and system restoration bonds, as of June 30, 2018, our subsidiaries had approximately $6.1 billion aggregate principal amount of third-party indebtedness outstanding, of which approximately $3.3 billion was secured, as well as other liabilities. In addition, we had the ability to borrow an additional $2.3 billion under our credit facilities and commercial paper program, collectively, subject to certain limitations. As of June 30, 2018, we have also entered into the Commitment Letter with a syndicate of banks providing, subject to customary conditions, for a $5.0 billion, 364-day senior unsecured Bridge Facility to backstop a portion of our obligation to pay the Merger Consideration.

The terms of the Series A Preferred Stock do not limit our ability to incur additional indebtedness. In connection with our financing of the Merger Consideration, we intend to issue debt securities and commercial paper, as part of the Additional Financings, which, along with our other outstanding indebtedness, will be senior to the Series A Preferred Stock. If we complete such a debt offering, we expect that we will use the net proceeds from that offering to partially finance the Merger Consideration. There can be no assurance that we will consummate any Additional Financings.

The payment of principal and interest on our debt reduces the cash available for payment of dividends on our capital stock, including the Series A Preferred Stock.

Our ability to issue additional shares of Series A Preferred Stock and Parity Stock in the future could adversely affect the rights of holders of the Series A Preferred Stock.

We are allowed to issue additional shares of Series A Preferred Stock or Parity Stock without any vote of the holders of the Series A Preferred Stock. For example, in connection with financing a portion of the consideration for the Vectren Merger, we may issue other classes of preferred stock that would constitute Parity Stock. The issuance of any Parity Stock (including additional shares of Series A Preferred Stock) would have the effect of reducing the amount of funds available to the holders of the shares of Series A Preferred Stock upon our liquidation, dissolution or winding up if we do not have sufficient funds to pay all liquidation preferences of the Series A Preferred Stock and Parity Stock in full. It also would reduce amounts available to pay dividends on the shares of Series A Preferred Stock if we do not have sufficient funds to pay dividends on all outstanding Series A Preferred Stock and Parity Stock. See “Description of Our Series A Preferred Stock — Dividends — Payment of

S-13

Dividends” herein. In addition, future issuances and sales of Parity Stock (including additional shares of Series A Preferred Stock), or the perception that such issuances and sales could occur, may cause prevailing market prices for the Series A Preferred Stock to decline and may adversely affect our ability to raise additional capital in the financial markets at times and prices favorable to us.

The Series A Preferred Stock may be subordinate to other preferred stock we may issue in the future.

The Series A Preferred Stock will be junior as to payment of dividends and preferences to any class or series of our preferred stock that may be issued (with the requisite consent of the holders of the Series A Preferred Stock and all other voting preferred stock then outstanding, voting together as a single class) in the future that is Senior Stock. For example, if at any time we have failed to pay, on the applicable payment date, accrued dividends on any of those shares of Senior Stock, we may not pay any dividends on the Series A Preferred Stock or redeem or otherwise repurchase any shares of Series A Preferred Stock until we have paid or set aside for payment the full amount of the unpaid dividends on the shares of Senior Stock, which must, under the terms of such shares, be paid before we may pay dividends on, or redeem or repurchase, the Series A Preferred Stock. In addition, in the event of any liquidation, dissolution or winding up of CenterPoint Energy, holders of the Series A Preferred Stock will not be entitled to receive the liquidation preference of their shares until we have paid or set aside an amount sufficient to pay in full the liquidation preference of any class or series of Senior Stock.

As a holder of Series A Preferred Stock you will have extremely limited voting rights.

Your voting rights as a holder of Series A Preferred Stock will be extremely limited. You will have no right to vote for any members of our board of directors except in the case of certain dividend arrearages. If dividends on any shares of the Series A Preferred Stock have not been declared and paid for the equivalent of three or more semi-annual or six or more quarterly dividend periods (including, for the avoidance of doubt, the dividend period beginning on, and including, the original issue date (as defined below) and ending on, but excluding, March 1, 2019), whether or not for consecutive dividend periods, the holders of such shares of Series A Preferred Stock, voting together as a single class with holders of any and all other series of voting preferred stock then outstanding, will be entitled at our next annual or special meeting of shareholders to vote for the election of a total of two additional members of our board of directors, subject to the terms and limitations described under “Description of Our Series A Preferred Stock — Voting Rights.”

We have the right under certain circumstances to redeem the Series A Preferred Stock prior to September 1, 2023 and may redeem the Series A Preferred Stock at our option, in whole or in part, on and after that date. You may not be able to reinvest the redemption price you receive in a similar security.

We may redeem the Series A Preferred Stock prior to September 1, 2023 upon the occurrence of a Ratings Event. Additionally, on or after September 1, 2023 we may redeem the Series A Preferred Stock at any time from time to time in whole or in part for cash.

If we redeem the Series A Preferred Stock for any reason, you may not be able to reinvest the redemption proceeds you receive in a similar security. See “Description of Our Series A Preferred Stock — Redemption” for more information on redemption of the Series A Preferred Stock.

The Series A Preferred Stock is not convertible into our common stock at any time and does not have any protection in the event of a change of control.

The Series A Preferred Stock is not convertible into our common stock at any time. In addition, the terms of the Series A Preferred Stock will not contain any provisions that protect the holders of the Series A Preferred Stock in the event that we experience a change of control. Holders of Series A Preferred Stock will have no voting rights with respect to any merger or other transaction in which either (x) we are the surviving entity and the Series A Preferred Stock remains outstanding or (y) the Series A Preferred Stock is exchanged for a series of

S-14

preferred stock of the surviving entity, in either case, with the terms thereof unchanged in any respect materially adverse to the holders of Series A Preferred Stock. Additionally, a consolidation or merger of us with or into any other entity, individually or in a series of transactions, will not be deemed to be a liquidation, dissolution or winding up of our affairs.

A change in our credit rating or the rating of the Series A Preferred Stock could adversely affect the market price of the Series A Preferred Stock.

The Series A Preferred Stock expects to receive ratings from Moody’s, S&P and Fitch. Rating agencies revise their ratings from time to time and could lower or withdraw any rating issued with respect to the Series A Preferred Stock. Any real or anticipated downgrade or withdrawal of any ratings of the Series A Preferred Stock could have an adverse effect on the market price or liquidity of the Series A Preferred Stock.

On April 24, 2018, Moody’s placed CenterPoint Energy, Inc.’s credit ratings for its senior unsecured debt on negative outlook and S&P placed its long-term ratings on CenterPoint Energy Inc. on CreditWatch with negative implications. Moody’s and S&P indicated that their actions were triggered by the proposed acquisition of Vectren and our expected increased leverage relating to our proposed financing of the Vectren Merger. Moody’s indicated that a one notch downgrade is likely if the Vectren Merger is financed as we have proposed. S&P, however, noted that its ratings action reflected the potential of a one to two notch downgrade. By maintaining our current business risk profile and issuing the Series A Preferred Stock offered hereby and a sufficient amount of common stock and mandatory convertible equity securities as part of the Additional Financings, we are targeting a BBB or better credit rating upon consummation of the Vectren Merger. A BBB rating would reflect a one notch downgrade from our current credit rating. Our targeted credit rating, however, is highly dependent on our ability to issue the Series A Preferred Stock offered hereby and the common stock and mandatory convertible equity securities as part of the Additional Financings, which is subject to market conditions and a number of other risks and uncertainties. Accordingly, we cannot guarantee that we will be able to achieve our targeted rating. Both agencies also indicated that a downgrade could occur at or before the closing of the Vectren Merger. Any downgrade of our credit ratings on our senior unsecured debt would result in a corresponding downgrade for the ratings on the Series A Preferred Stock. The negative outlook by Moody’s and S&P, any downgrade of our credit ratings by S&P, Fitch Ratings, Moody’s or any other rating agency, or any additional negative outlook on our credit ratings may adversely affect the market price of our debt securities, common stock and Series A Preferred Stock and could make it more costly for us to issue debt securities, to borrow under our credit facilities and to raise certain other types of financing, including in connection with the Vectren Merger.

Ratings reflect only the views of the issuing rating agency or agencies and are not recommendations to purchase, sell or hold any particular security, including the Series A Preferred Stock. In addition, ratings do not reflect market prices or suitability of a security for a particular investor, and any future rating of the Series A Preferred Stock may not reflect all risks related to us and our business or the structure or market value of the Series A Preferred Stock.

There is no prior public market for the Series A Preferred Stock, and we cannot assure you that any public market will develop or be sustained after this offering. In addition, the lack of a fixed redemption date for the Series A Preferred Stock will increase your reliance on the secondary market for liquidity purposes.

The Series A Preferred Stock will constitute a new issue of securities without an established trading market. We do not intend to list the Series A Preferred Stock on any securities exchange or to seek approval for quotations through any automated quotation system. As a result, a market may not develop for the Series A Preferred Stock, and you may not be able to sell your shares of Series A Preferred Stock. In addition, since the Series A Preferred Stock has no stated maturity date, and we have no obligation to redeem the Series A Preferred Stock at any time, holders of Series A Preferred Stock seeking liquidity will be limited to selling their shares of Series A Preferred Stock in the secondary market absent redemption by us. In addition, the condition of the

S-15

financial markets and prevailing interest rates have fluctuated in the past and are likely to fluctuate in the future, which could have an adverse effect on the market prices of the Series A Preferred Stock. Accordingly, you may be required to bear the financial risk of an investment in the Series A Preferred Stock for an indefinite period of time. There can be no assurance that a market for the Series A Preferred Stock will develop or, if it does develop, that it will continue. If an active public market does not develop, the market price and liquidity of the Series A Preferred Stock may be adversely affected.

Market interest rates may adversely affect the value of the Series A Preferred Stock, and the dividend payable on the Series A Preferred Stock will vary on and after September 1, 2023 based on market interest rates.

One of the factors that will influence the price of the Series A Preferred Stock will be the dividend yield on the Series A Preferred Stock (as a percentage of the price of the Series A Preferred Stock) relative to market interest rates. An increase in market interest rates may lead prospective purchasers of the Series A Preferred Stock to expect a higher dividend yield, and higher interest rates would likely increase our borrowing costs and potentially decrease funds available to pay dividends to our shareholders, including the holders of the Series A Preferred Stock. Accordingly, higher market interest rates could cause the market price of the Series A Preferred Stock to decrease.

In addition, on and after September 1, 2023, the Series A Preferred Stock will have a floating dividend rate set equal to a floating rate of the then-current three-month LIBOR plus a spread of 3.270% per annum. The per annum dividend rate that is determined on the relevant determination date will apply to the entire quarterly period following such determination date even if LIBOR increases during that period. As a result, the holders of the Series A Preferred Stock will be subject to risks associated with fluctuation in interest rates and the possibility that holders of Series A Preferred Stock will receive dividends that are lower than expected or lower than the fixed rate during the initial period. We have no control over a number of factors, including economic, financial and political events, that impact market fluctuations in interest rates, which have in the past and may in the future experience volatility.

If LIBOR is discontinued, dividends on the Series A Preferred Stock during the floating-rate period may be calculated using another base rate.

On July 27, 2017, the Chief Executive of the U.K. Financial Conduct Authority (the “FCA”), which regulates the London Interbank Offered Rate (“LIBOR”), announced that the FCA will no longer persuade or compel banks to submit rates for the calculation of LIBOR (including the three-month LIBOR rate) after 2021. Such announcement indicates that the continuation of LIBOR on the current basis cannot be guaranteed after 2021. Based on the foregoing, it appears likely that LIBOR will be discontinued or modified by 2021. Under the terms of the Series A Preferred Stock, the dividend rate on the Series A Preferred Stock for each dividend period during the floating-rate period is based on three-month LIBOR. If the calculation agent is unable to determine three-month LIBOR based on screen-based reporting of that base rate, and if the calculation agent is also unable to obtain suitable quotations for three-month LIBOR from reference banks, then the calculation agent will determine three-month LIBOR in its sole discretion after consulting with us and such sources as it deems comparable or reasonable. In addition, if the calculation agent determines on the relevant dividend determination date that three-month LIBOR for deposits in U.S. dollars having an index maturity of three months in amounts of at least $1,000,000 has been discontinued, then the calculation agent will use as a substitute for three-month LIBOR, the alternative reference rate selected by the central bank, reserve bank, monetary authority or similar institution that is consistent with accepted market practice. In such instances, the calculation agent may determine what business day convention to use, the definition of business day, the dividend determination date and any other relevant methodology for calculating such substitute base rate, including any adjustment factor needed to make such substitute base rate comparable to the three-month LIBOR base rate, in a manner that is consistent with accepted market practice, with respect to the calculation of dividends on the Series A Preferred Stock during the floating-rate period. If the calculation agent determines that the three-month LIBOR has been discontinued and no market accepted substitute rate has been determined, then three-month LIBOR used to

S-16

determine the applicable dividend rate will be the last available three-month LIBOR as determined by the calculation agent. Any of the foregoing determinations or actions by the calculation agent could result in adverse consequences to the applicable dividend rate on the Series A Preferred Stock during the floating-rate period, which could adversely affect the return on, value of and market for the Series A Preferred Stock. The calculation agent has not been appointed, and we will appoint a calculation agent for the Series A Preferred Stock prior to the commencement of the floating-rate period.

Regulation and reform of interest rate “benchmarks,” including LIBOR, may cause such “benchmarks” to perform differently than in the past, to disappear entirely or to have other consequences which cannot be predicted.

LIBOR and other interest rate, equity, foreign exchange rate and other types of indices which are deemed to be “benchmarks” are the subject of recent international, national and other regulatory guidance and proposals for reform. Some of these reforms are already effective while others are still to be implemented. These reforms may cause such “benchmarks” to perform differently than in the past, or to disappear entirely, or have other consequences which cannot be predicted. Any such consequence could have a material adverse effect on the return on, value of and market for the Series A Preferred Stock. Any of the international, national or other proposals for reform or the general increased regulatory scrutiny of LIBOR and other “benchmarks” could increase the costs and risks of administering or otherwise participating in the setting of such “benchmarks” and complying with any such regulations or requirements. Such factors may have the effect of discouraging market participants from continuing to administer or contribute to certain “benchmarks,” trigger changes in the rules or methodologies used in certain “benchmarks” or lead to the disappearance of certain “benchmarks.” In particular, changes in the manner of administration of LIBOR could result in adverse consequences to the applicable dividend rate on the Series A Preferred Stock during the floating-rate period, which could adversely affect the return on, value of and market for the Series A Preferred Stock.

This offering is not contingent upon the completion of the Vectren Merger. If the Vectren Merger is not completed, we will have broad discretion on the use of the net proceeds of this offering.

This offering is not contingent upon the completion of the Vectren Merger. Accordingly, your purchase of shares of Series A Preferred Stock in this offering may be an investment in CenterPoint Energy on a stand-alone basis without any of the assets of Vectren or anticipated benefits of the Vectren Merger. We will have broad discretion to use the net proceeds of this offering if the Vectren Merger does not occur. If for any reason the proposed Vectren Merger is not consummated, then we expect to use the net proceeds of this offering for general corporate purposes, which may include, in our sole discretion, debt repayment, including repayment of commercial paper, capital expenditures, investments and repurchases of our common stock at the discretion of our board of directors. See “Use of Proceeds.”

CenterPoint Energy expects to incur significant additional indebtedness in connection with the Vectren Merger. As a result, it may be more difficult for CenterPoint Energy to pay or refinance its debts or take other actions, and CenterPoint Energy may need to divert cash to fund debt service payments.

As discussed under “Summary — Recent Developments — Vectren Merger Financing” and “Summary —Recent Developments — Sources and Uses,” CenterPoint Energy expects to incur significant additional indebtedness to finance the Merger Consideration and related transaction costs. The Vectren Merger will constitute a “Change of Control” under the governing documents of approximately $1.3 billion of debt of Vectren subsidiaries. While the Vectren Merger will not result in an event of default under such debt documents nor will it compel holders of such debt to tender their debt, the Vectren subsidiaries will be required to offer to repurchase such debt at par upon the closing of the Vectren Merger. Moreover, although CenterPoint Energy plans to fund a significant portion of the Merger Consideration through sales of the Series A Preferred Stock offered hereby and common stock and mandatory convertible equity securities, to the extent it is unable to do so, the amount of indebtedness it will incur to finance the Vectren Merger and associated fees and costs will likely

S-17

increase, perhaps substantially. The increase in CenterPoint Energy’s debt service obligations resulting from this additional indebtedness could have a material adverse effect on the results of operations, financial condition and prospects of the combined company.

CenterPoint Energy’s increased indebtedness could:

Based on the current and expected results of operations and financial condition of CenterPoint Energy and its subsidiaries and the anticipated financing structure for the Vectren Merger, CenterPoint Energy believes that its cash flow from operations, together with the proceeds from borrowings, issuances of equity and debt securities in the capital markets and distributions from its interests in Enable will generate sufficient cash on a consolidated basis to make all of the principal and interest payments when such payments are due under CenterPoint Energy’s and its current subsidiaries’ existing credit facilities, indentures and other instruments governing their outstanding indebtedness and under the indebtedness anticipated to be incurred to fund the Merger Consideration. However, CenterPoint Energy’s expectation is subject to numerous estimates, assumptions and uncertainties, and there can be no assurance that CenterPoint Energy will be able to make such payments of principal and interest or repay or refinance such borrowings and obligations when due. Vectren and its subsidiaries will not guarantee any indebtedness of CenterPoint Energy or any of its other subsidiaries, nor will any of them have any obligation to provide funds, whether in the form of dividends, loans or otherwise, to

S-18

enable CenterPoint Energy to pay dividends on its common stock or the Series A Preferred Stock or CenterPoint Energy and its other subsidiaries to make required debt service payments. As a result, the Vectren Merger will substantially increase CenterPoint Energy’s debt service obligations without any assurance that CenterPoint Energy will receive any cash from Vectren or any of its subsidiaries to assist CenterPoint Energy in servicing its indebtedness, paying dividends on its common stock and Series A Preferred Stock or meeting its other cash needs.

CenterPoint Energy is committed to maintaining its credit ratings at investment grade. To maintain these credit ratings, CenterPoint Energy may consider it appropriate to reduce the amount of its indebtedness outstanding following the Vectren Merger. CenterPoint Energy may seek to reduce this indebtedness with the proceeds from the issuance of additional shares of Series A Preferred Stock or Parity Stock, which may dilute the voting rights and economic interests of holders of the Series A Preferred Stock. However, the ability of CenterPoint Energy to raise additional equity financing after completion of the Vectren Merger will be subject to market conditions and a number of other risks and uncertainties, including whether the results of operations of the combined company meet the expectations of investors and securities analysts. There can be no assurance that CenterPoint Energy will be able to issue additional shares of its common stock or other equity securities (including Series A Preferred Stock or Parity Stock) after the Vectren Merger on terms that it considers acceptable or at all, or that CenterPoint Energy will be able to reduce the amount of its outstanding indebtedness after the Vectren Merger, should it elect to do so, to a level that permits it to maintain its investment grade credit ratings.

If the proposed Vectren Merger is consummated and this offering or the equity portion of the Additional Financings is not completed (or results in aggregate net cash proceeds significantly less than contemplated by this prospectus supplement), we may incur a substantially greater amount of debt than we anticipate, including borrowings under the Bridge Facility or our revolving credit facility or commercial paper program. This additional debt could adversely affect our business, including by restricting our ability to engage in additional transactions or incur additional indebtedness or resulting in a downgrade or other adverse action with respect to our credit rating.

In connection with the proposed Vectren Merger, we expect to incur up to approximately $3.08 billion of additional indebtedness as part of the Additional Financings, and if and to the extent this offering or the equity portion of the Additional Financings are not completed (for any reason, including satisfying all closing conditions, including regulatory requirements, faster than anticipated) or are completed for less proceeds than anticipated, we would fund any shortfall with additional indebtedness, which may include borrowings under the Bridge Facility or our revolving credit facility or commercial paper program. In all cases, following the completion of the proposed Vectren Merger, we will continue to have a significant amount of debt outstanding. Our net consolidated borrowing costs, which cannot be predicted at this time, will depend on rates in effect from time to time, the structure of the debt, taxes and other factors.

In addition, any borrowings under the Bridge Facility will mature 364 days after they are incurred. We may not be able to refinance borrowings under the Bridge Facility on favorable terms or at all before their maturity. In addition, the interest rate applicable to borrowings under the Bridge Facility will increase at the end of each three-month period after the borrowing date. Accordingly, we may incur additional interest expense if we are unable to refinance borrowings under the Bridge Facility before the interest rate increases take effect.

Our credit ratings impact the cost and availability of future borrowings and, accordingly, our cost of capital. Our credit ratings at any time will reflect each rating organization’s then opinion of our financial strength, operating performance and ability to meet our debt obligations. There can be no assurance that we will achieve a particular rating or maintain a particular rating in the future. Any reduction in our credit ratings may limit our ability to borrow at interest rates consistent with the interest rates that have been available to us prior to the proposed Vectren Merger, and may subject us to additional covenants under our debt instruments. Any impairment of our ability to obtain future financing on favorable terms could have an adverse effect on our

S-19

ability to refinance the Bridge Facility, if drawn, with the issuance of debt securities and commercial paper or alternatives to the Bridge Facility on terms more favorable than under the Bridge Facility.

The unaudited pro forma condensed combined financial information included and incorporated by reference in this prospectus supplement and the accompanying prospectus is presented for illustrative purposes only and does not purport to represent what the financial position or results of operations of the combined company would have been had the Vectren Merger been completed on the dates assumed for purposes of that pro forma information, nor does it represent the actual financial position or results of operations of the combined company following the Vectren Merger, if consummated.

The unaudited pro forma condensed combined financial information included and incorporated by reference in this prospectus supplement and the accompanying prospectus is presented for illustrative purposes only, is based on numerous adjustments, assumptions and estimates, is subject to numerous other uncertainties and does not purport to reflect what the combined company’s financial position or results of operations would have been had the Vectren Merger been completed as of the dates assumed for purposes of that pro forma financial information, nor does it reflect the financial position or results of operations of the combined company following the Vectren Merger, if consummated.

Because the Additional Financings are contemplated to take place in the future, the pro forma financial statements were prepared in accordance with the accounting rules assuming that the Merger Consideration will be financed from drawings under the Bridge Facility and under our revolving credit facility and through the proceeds from the issuance of the Series A Preferred Stock offered hereby. See “Unaudited Pro Forma Condensed Combined Financial Information.” However, we do not intend to draw on the Bridge Facility or our revolving credit facility but rather intend to fund the Merger Consideration with proceeds received through the Additional Financings, in addition to the proceeds from the issuance of the Series A Preferred Stock offered hereby, although there is no guarantee that we will be able to consummate the Additional Financings as planned or at all. As a result, purchasers of our Series A Preferred Stock offered hereby should not place undue reliance on the pro forma information included and incorporated by reference in this prospectus supplement and the accompanying prospectus.

For purposes of the unaudited pro forma condensed combined financial information, the estimated Merger Consideration has been preliminarily allocated to the identifiable assets acquired and liabilities assumed based on limited information presently available to estimate fair values. The Merger Consideration will be allocated among the relative fair values of the identifiable assets acquired and liabilities assumed based on their estimated fair values as of the date of the Vectren Merger. The relative fair values of the assets acquired and liabilities assumed are estimates, which are subject to change pending further review. The actual amounts recorded at the completion of the Vectren Merger, if completed, may differ materially from the information presented in the unaudited pro forma condensed combined financial information.

The unaudited pro forma condensed combined financial information has also been prepared on the assumption that the Vectren Merger and the related financings will be completed on the terms and in accordance with the assumptions set forth under “Unaudited Pro Forma Condensed Combined Financial Information” included in this prospectus supplement and incorporated by reference in this prospectus supplement and the accompanying prospectus. Any changes in these assumptions would result in a change in the unaudited pro forma condensed combined financial information, which could be material. In addition, because none of the potential methods of financing the Vectren Merger will be contingent upon completion of any of the other, it is possible that one or more of such methods of financing will not be completed. It is also possible that such financings, if completed, will not generate the anticipated amount of net proceeds, which may require us to obtain additional or alternative financing, and we may not be able to obtain additional or alternative financing on terms we consider acceptable, or at all. See “Unaudited Pro Forma Condensed Combined Financial Information” and each of our and Vectren’s consolidated financial statements included or incorporated by reference in this prospectus supplement and the accompanying prospectus.

S-20

Our and Vectren’s actual financial positions and results of operations prior to the Vectren Merger and that of the combined company following the Vectren Merger, if consummated, may not be consistent with, or evident from, the unaudited pro forma condensed combined financial information included and incorporated by reference in this prospectus supplement and the accompanying prospectus. In addition, the assumptions or estimates used in preparing the unaudited pro forma condensed combined financial information may not prove to be accurate and may be affected by a broad range of factors.

Although the unaudited pro forma condensed combined financial information included and incorporated by reference in this prospectus supplement includes sensitivity analyses that are intended to assist you in quantifying the impact of changes in certain of the assumptions used in preparing such pro forma information, those sensitivity analyses reflect the pro forma impact of only a limited number of those assumptions and therefore do not allow you to quantify the impact of changes in any of the other assumptions made in calculating this pro forma information and changes in certain of those other assumptions may have a material impact on the unaudited pro forma condensed combined financial information. Likewise, the sensitivity analyses we have provided do not necessarily address the impact of all possible changes in the relevant assumptions. We have not updated the unaudited pro forma condensed combined financial information to reflect any of the other actual terms of this offering.

As a result of the foregoing, purchasers of shares of Series A Preferred Stock should not place undue reliance on unaudited pro forma condensed combined financial information included and incorporated by reference in this prospectus supplement and the accompanying prospectus.

If we incur indebtedness or issue debt securities to finance a portion of the Merger Consideration, and we do not complete the Vectren Merger on or before a specified date or if other specified events occur, we may be required or permitted to redeem or repay any such indebtedness or debt securities. We may not have the financial resources necessary to effect such redemption or repayment. It is possible that our failure to complete the Vectren Merger or the expenditure of our funds to redeem or repay any indebtedness incurred as part of the Additional Financings may have a material adverse effect on the market price of the Series A Preferred Stock.

We expect to incur a substantial amount of additional indebtedness as part of the Additional Financings. See “Summary — Recent Developments — Sources and Uses.” To the extent we incur indebtedness or issue debt securities as all or part of the Additional Financings and we do not complete the Vectren Merger by a specified date or if certain other specified events, such as termination of the Merger Agreement, occur, we may be required or permitted to redeem or repay some or all of such indebtedness and debt securities and that the redemption or repayment price will include a premium, which premium could be substantial. Likewise, if the Additional Financings include the issuance of additional shares of our preferred stock, we may be required or permitted to redeem that preferred stock if the Vectren Merger does not occur by a specified date or other specified events occur and the redemption price may also include a premium, which premium could be substantial.

We may not be required to deposit the proceeds from the Additional Financings into an escrow account pending completion of the Vectren Merger or to grant any security interest or other lien on those proceeds to secure any required repayment or redemption of any Additional Financings. If we are required to redeem or repay any indebtedness or debt securities issued in the Additional Financings, our ability to pay the redemption or repayment price may be limited by our financial resources at the time and the terms of our debt instruments or other instruments and agreements and it is possible that we will not have sufficient financial resources available to satisfy our obligation to effect such redemption or repayment. Any failure to pay the mandatory redemption or repayment price of any Additional Financings as and when required could have a material adverse effect on our business, results of operations and financial condition and the market price of our securities, including the Series A Preferred Stock, or any indebtedness incurred or other securities issued as part of the Additional Financings. It is possible that our failure to complete the Vectren Merger, or the expenditure of our funds to redeem or repay any Additional Financings, may have a material adverse effect on the market price of the Series A Preferred Stock.

S-21

The Vectren Merger will significantly increase our goodwill and other intangible assets.

Following the Vectren Merger we will have a significant amount of goodwill and other intangible assets on our consolidated financial statements that are subject to impairment based upon future adverse changes in our business or prospects. The impairment of any goodwill and other intangible assets may have negative impact on our consolidated results of operations.

Litigation filed against Vectren and the members of the Vectren board of directors could prevent or delay the consummation of the Vectren Merger or result in the payment of damages following completion of the Vectren Merger.

In connection with the Vectren Merger, seven purported Vectren shareholders filed separate lawsuits against Vectren and the members of the Vectren board of directors under the federal securities laws in the United States District Court for the Southern District of Indiana challenging the adequacy of the disclosures made in Vectren’s proxy statement in connection with the Vectren Merger. All seven actions allege violations of Sections 14(a) and 20(a) of the Exchange Act and Rule 14a-9 promulgated thereunder based on various alleged omissions of material information from the proxy statement.

The lawsuits seek, among other things, to enjoin the Vectren Merger or, if the Vectren Merger is consummated, to rescind the Vectren Merger or award rescissory damages, and other relief. The outcome of any such litigation is uncertain. If dismissals are not granted or a settlement is not reached, the lawsuits could prevent or delay completion of the Vectren Merger and result in substantial costs to CenterPoint Energy, including any costs associated with indemnification. Additional lawsuits may be filed against Vectren or the directors and officers of Vectren in connection with the Vectren Merger. The defense or settlement of any lawsuit or claim that remains unresolved at the time the Vectren Merger is consummated may adversely affect the combined company’s business, financial condition, results of operations and cash flows.

S-22

USE OF PROCEEDS

We estimate that the net proceeds to us from this offering, after deducting the underwriting discount and estimated offering expenses payable by us, will be approximately $790 million.

We intend to use net proceeds from this offering and the Additional Financings to fund the Merger Consideration and to pay related fees and expenses. See “Summary — Recent Developments.” However, this offering is not contingent on the completion of the Vectren Merger or the Additional Financings, and there can be no assurance that the Vectren Merger or any Additional Financings will be consummated on the terms described herein or at all. If for any reason the proposed Vectren Merger is not consummated on or prior to April 21, 2019, or the Merger Agreement is terminated at any time prior to such date, then we expect to use the net proceeds from this offering for general corporate purposes, which may include, in our sole discretion, debt repayment, including repayment of commercial paper, capital expenditures, investments and repurchases of our common stock at the discretion of our board of directors.

Pending application of the net proceeds of this offering for the foregoing purposes, we expect to use the net proceeds to repay commercial paper and other short-term indebtedness that were issued or incurred for general corporate and working capital purposes or invest such net proceeds in various instruments which may include, but would not be limited to, short- and intermediate-term, interest-bearing obligations, including bank deposits and certificates of deposit with financial institutions having investment-grade ratings, U.S. government obligations or money market funds primarily invested in securities issued by the U.S. government or its agencies.

On June 30, 2018, we had $565 million of commercial paper borrowings, which had a weighted-average maturity of 17 days and a weighted-average interest rate of 2.37%. For information regarding the interest rate and maturity of our other debt, see Note 13 to our Financial Statements in the 2017 Form 10-K as updated by our other filings with the SEC.

S-23

RATIOS OF EARNINGS TO FIXED CHARGES AND RATIOS OF EARNINGS TO COMBINED FIXED CHARGES AND PREFERRED STOCK DIVIDENDS

The following table sets forth our historical ratio of earnings to fixed charges for the periods indicated. The ratios are calculated pursuant to the applicable rules of the SEC.

S-24

CAPITALIZATION

The following table sets forth our consolidated short-term debt and capitalization as of June 30, 2018:

The following table does not give effect to (1) any potential issuance and sale of common stock or mandatory convertible equity securities or (2) the incurrence of any indebtedness, including the issuance of debt securities and commercial paper or drawing on the Bridge Facility or our revolving credit facility, to finance a portion of the Merger Consideration and related fees and expenses.

This table should be read in conjunction with our consolidated financial statements and related notes thereto and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” included in our 2017 Form 10-K and our 2nd Quarter 2018 Form 10-Q.

S-25

UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION

The Unaudited Pro Forma Condensed Combined Financial Statements (pro forma financial statements) have been derived from the historical consolidated financial statements of CenterPoint Energy, Inc. (CenterPoint Energy) and Vectren Corporation (Vectren). The following pro forma financial statements should be read in conjunction with:

On April 21, 2018, CenterPoint Energy entered into an Agreement and Plan of Merger (Merger Agreement), by and among CenterPoint Energy, Vectren and Pacer Merger Sub, Inc., an Indiana corporation and wholly owned subsidiary of CenterPoint Energy (Merger Sub). Pursuant to the Merger Agreement, on and subject to the terms and conditions set forth therein, Merger Sub will merge with and into Vectren (Vectren Merger), with Vectren continuing as the surviving corporation in the Vectren Merger and becoming a wholly owned subsidiary of CenterPoint Energy.

The Unaudited Pro Forma Condensed Combined Statements of Income (pro forma statements of income) for the six months ended June 30, 2018, and the year ended December 31, 2017, give effect to the Vectren Merger as if it were completed on January 1, 2017. The Unaudited Pro Forma Condensed Combined Balance Sheet (pro forma balance sheet) as of June 30, 2018, gives effect to the Vectren Merger as if it were completed on June 30, 2018.

The historical financial information has been adjusted in the pro forma financial statements to give effect to pro forma events that are (i) directly attributable to the Vectren Merger, (ii) factually supportable and (iii) with respect to the statements of income, expected to have a continuing impact on the combined results of CenterPoint Energy and Vectren.

The Vectren Merger will be accounted for as an acquisition of Vectren common shares by CenterPoint Energy and will follow the acquisition method of accounting for business combinations. The pro forma financial statements reflect an aggregate purchase price of approximately $6.0 billion in cash, based upon the “Merger Consideration” (as defined in the Merger Agreement) of $72.00 per share for each share of common stock of Vectren issued and outstanding immediately prior to the Vectren Merger.

CenterPoint Energy has obtained committed financing in the form of a $5.0 billion senior unsecured bridge term loan facility (Bridge Facility) from Goldman Sachs Bank USA and Morgan Stanley Senior Funding, Inc. Any borrowings under the Bridge Facility would be classified as short-term debt in current liabilities. CenterPoint Energy has prepared its pro forma financial statements in accordance with the applicable accounting rules assuming the aggregate purchase price will be financed by borrowings under the Bridge Facility and

S-26

CenterPoint Energy’s existing revolving credit facility and the issuance by CenterPoint Energy of $500 million of its Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Stock, par value $0.01 per share (Series A Preferred Stock). However, CenterPoint Energy anticipates financing the Vectren Merger through its expected issuances of Series A Preferred Stock, common stock, mandatory convertible equity securities, debt securities and commercial paper, subject to then current market conditions, as well as cash on hand. CenterPoint Energy’s permanent financing assumptions are detailed in the accompanying notes.

Assumptions and estimates underlying the pro forma adjustments are described in the accompanying notes, which should be read with the pro forma financial statements. Because the pro forma financial statements have been prepared on preliminary estimates, the total amounts recorded at the date of the Vectren Merger may differ materially from the information presented in the pro forma financial statements. These estimates are subject to change pending further review of the assets acquired and liabilities assumed in the Vectren Merger and the final purchase price of the Vectren Merger.

The pro forma financial statements have been presented for illustrative purposes only and are not necessarily indicative of the results of operations and financial position that would have been achieved had the pro forma events taken place on the dates indicated, or the future consolidated results of operations or financial position of the combined company.

S-27

CENTERPOINT ENERGY, INC.

UNAUDITED PRO FORMA CONDENSED COMBINED BALANCE SHEET

June 30, 2018

See Notes to Unaudited Pro Forma Condensed Combined Financial Statements

S-28

CENTERPOINT ENERGY, INC.

UNAUDITED PRO FORMA CONDENSED COMBINED BALANCE SHEET — (continued)

June 30, 2018

See Notes to Unaudited Pro Forma Condensed Combined Financial Statements

S-29

CENTERPOINT ENERGY, INC.

UNAUDITED PRO FORMA CONDENSED COMBINED STATEMENT OF INCOME

For the Six Months Ended June 30, 2018

See Notes to Unaudited Pro Forma Condensed Combined Financial Statements

S-30

CENTERPOINT ENERGY, INC.

UNAUDITED PRO FORMA CONDENSED COMBINED STATEMENT OF INCOME

For the Year Ended December 31, 2017

See Notes to Unaudited Pro Forma Condensed Combined Financial Statements

S-31

CENTERPOINT ENERGY, INC.

NOTES TO UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL STATEMENTS

(1) Basis of presentation

The pro forma statements of income for the six months ended June 30, 2018, and the year ended December 31, 2017, give effect to the Vectren Merger as if it were completed on January 1, 2017. The pro forma balance sheet as of June 30, 2018, gives effect to the Vectren Merger as if it were completed on June 30, 2018.

The pro forma financial statements have been derived from the historical consolidated financial statements of CenterPoint Energy and Vectren. Certain financial statement line items included in Vectren’s historical presentation have been reclassified to conform to corresponding financial statement line items included in CenterPoint Energy’s historical presentation (see Note 6). These reclassifications have no material impact on the historical operating income, net income, total assets, total liabilities or shareholders’ equity reported by CenterPoint Energy or Vectren. The historical consolidated financial statements have been adjusted in the pro forma financial statements to give effect to pro forma events that are (1) directly attributable to the business combination, (2) factually supportable and (3) with respect to the pro forma statements of income, expected to have a continuing impact on the combined results following the Vectren Merger.

Assumptions and estimates underlying the pro forma adjustments are described in these notes, which should be read in conjunction with the pro forma financial statements. Since the pro forma financial statements have been prepared based upon preliminary estimates, the final amounts recorded at the date of the Vectren Merger may differ materially from the information presented. These estimates are subject to change pending further review.

The Vectren Merger is reflected in the pro forma financial statements as an acquisition of Vectren by CenterPoint Energy, based on the guidance provided by accounting standards for business combinations. Under these accounting standards, the total estimated purchase price is allocated as described in Note 2 to the pro forma financial statements, and the assets acquired and the liabilities assumed have been measured at estimated fair value.

Vectren’s regulated operations are comprised of electric generation and electric and natural gas energy delivery services. These operations are subject to the rate-setting authority of the Federal Energy Regulatory Commission, the Indiana Utility Regulatory Commission and the Public Utilities Commission of Ohio, and are accounted for pursuant to U.S. generally accepted accounting principles, including the accounting guidance for regulated operations. The rate-setting and cost-recovery provisions currently in place for Vectren’s regulated operations provide revenue derived from costs including a return on investment of assets and liabilities included in rate base. Thus, the fair values of Vectren’s tangible and intangible assets and liabilities subject to these rate-setting provisions approximate their carrying values, and the pro forma financial statements do not reflect any net adjustments related to these amounts. Therefore, the excess purchase price over carrying value of net assets attributable to regulated operations is estimated to be compromised entirely of goodwill. The carrying values of Vectren’s non-regulated property, plant and equipment, which consists primarily of vehicles and equipment, and long-term debt, including the elimination of debt issuance costs, as of June 30, 2018, were reviewed and determined to approximate fair value; therefore, no fair value adjustment was reflected in the pro forma financial statements related to these balances.

The accounting policies used in the preparation of the pro forma financial statements are those described in CenterPoint Energy’s audited consolidated financial statements as of and for the year ended December 31, 2017. CenterPoint Energy performed a preliminary review of Vectren’s accounting policies to determine whether any adjustments were necessary to ensure comparability in the pro forma financial statements. At this time, CenterPoint Energy is not aware of any differences that would have a material effect on the pro forma financial statements, including any differences in the timing of adoption of new accounting standards, except for certain

S-32

amounts that have been reclassified to conform to CenterPoint Energy’s financial statement presentation (see Note 6). Upon completion of the Vectren Merger, or as more information becomes available, CenterPoint Energy will perform a more detailed review of Vectren’s accounting policies. As a result of that review, differences may be identified between the accounting policies of the two companies that, when conformed, could have a material impact on the pro forma financial statements. The 2017 historical statements of income for CenterPoint Energy and Vectren do not reflect new accounting standards retrospectively adopted on January 1, 2018.

CenterPoint Energy reviewed the historical financial information for intercompany transactions and found no eliminations were necessary. Transaction costs recorded in the historical income statement have been excluded from the pro forma statements of income as they reflect nonrecurring charges directly related to the Vectren Merger. However, the transaction costs not recorded in the historical balance sheet are reflected in the pro forma balance sheet as an increase in other current liabilities and a decrease in retained earnings when such amounts are not reflected in the historical balance sheet.

The pro forma financial statements do not reflect the realization of any expected cost savings or other synergies from the Vectren Merger as a result of restructuring activities following the completion of the Vectren Merger. Certain of Vectren employment agreements contain severance or other termination arrangements; however, the pro forma financial statements do not reflect any such payments under these arrangements as employment decisions have not been finalized.

(2) Estimated Purchase Price Consideration and Preliminary Purchase Price Allocation

The estimated purchase price consideration of approximately $6.0 billion is based on the cash price of $72.00 per outstanding share of common stock of Vectren. The value of the purchase price consideration will change based on the actual number of shares of common stock of Vectren issued and outstanding immediately prior to the Vectren Merger.

CenterPoint Energy has performed a preliminary valuation analysis of the fair market value of Vectren’s assets and liabilities. The following table summarizes the allocation of the preliminary purchase price as of the acquisition date (in millions):

S-33

This preliminary purchase price allocation has been used to prepare pro forma adjustments in the pro forma balance sheet and income statement. CenterPoint Energy has not completed a final valuation analysis necessary to determine the fair market values of all of Vectren’s assets and liabilities or the allocation of its purchase price. The final allocation could differ materially from the preliminary allocation used in the pro forma adjustments. The final allocation may include (1) changes in fair values of property, plant and equipment, (2) changes in allocations to intangible assets and goodwill and (3) other changes to assets and liabilities.

(3) Financing Transactions

CenterPoint Energy sometimes refers to the planned issuance and sale of its common stock, mandatory convertible equity securities, Series A Preferred Stock, debt securities and commercial paper as described below (collectively, the Additional Financings). The actual size and terms of, and amounts of proceeds CenterPoint Energy receives from, the respective Additional Financings will depend on, among other things, market conditions at the time of the Additional Financings and such other factors as CenterPoint Energy deems relevant and may differ, perhaps substantially, from the size, terms and amounts CenterPoint Energy has assumed in this Note 3 to the pro forma financial statements.

As required by accounting rules and for purposes of the pro forma financial statements, CenterPoint Energy has assumed the following to fund the approximately $6.0 billion cash consideration purchase price further described below:

CenterPoint Energy obtained commitments by lenders for a $5.0 billion, 364-day Bridge Facility to provide flexibility for the timing of the acquisition financing and fund, in part, amounts payable by CenterPoint Energy in connection with the Vectren Merger. For purposes of the pro forma financial statements, CenterPoint Energy’s assumed borrowings under the Bridge Facility of $4.5 billion were reduced by the assumed issuance of $500 million of Series A Preferred Stock offered hereby. For purposes of the pro forma financial statements, CenterPoint Energy has assumed a weighted-average interest rate of 5.3%, which includes duration and drawn fees on the $4.5 billion Bridge Facility borrowings. Drawn fees are estimated based on current 1-month LIBOR of 2.08% as of August 7, 2018, plus applicable margin under the Bridge Facility agreements. The Bridge Facility bears interest at an annual rate equal to LIBOR plus a margin ranging from 1.0% to 2.0%, depending on our credit rating, subject to an increase of 0.25% for each 90 days that elapse after the closing of the Vectren Merger. Assuming CenterPoint Energy, Inc.’s current credit ratings, the applicable margin increases 0.25% each 90 days after the closing of the Vectren Merger, from 1.25% to a maximum of 2.00%. Upon execution of the Bridge Facility, CenterPoint Energy deferred debt issuance costs of $25 million in other assets, of which $7 million was amortized as debt issuance expense in the historical financial statements as of and for the six months ended June 30, 2018.

For purposes of the pro forma financial statements, CenterPoint Energy has presented the issuance of 500,000 shares of its Series A Preferred Stock for $492 million, net of $8 million of issuance costs and discounts, with an aggregate liquidation value of $500 million, and that those shares will require CenterPoint Energy to pay dividends in cash, calculated as a percentage of the aggregate liquidation value, at the rate of 6% per annum. This assumed dividend rate is based on current market conditions. The actual dividend rate on the Series A Preferred Stock at the time it is issued may differ, perhaps substantially, from the rate CenterPoint Energy has assumed for purposes of the pro forma financial statements. In addition, CenterPoint Energy has further assumed that none of the shares of the Series A Preferred Stock have been redeemed early by CenterPoint Energy during the periods presented in the pro forma financial statements.

In May 2018, CenterPoint Energy entered into an amendment to its revolving credit facility (as so amended, the Revolving Credit Facility) that will increase the aggregate commitments from $1.7 billion to $3.3 billion

S-34

effective the earlier of (i) the termination of all commitments by certain lenders to provide the Bridge Facility and (ii) the payment in full of all obligations (other than contingent obligations) under the Bridge Facility and termination of all commitments to advance additional credit thereunder, and in each case, so long as the Merger Agreement has not been terminated pursuant to the terms thereof without consummation of the Vectren Merger. For purposes of the pro forma financial statements, CenterPoint Energy has assumed the balance of the purchase price consideration will be met by borrowings of approximately $1.0 billion under the Revolving Credit Facility at a weighted-average interest rate of 3.6%. Interest expense reflected in the pro forma financial statements includes arranger and commitments fees, as well as estimated interest on drawn amounts based on current 1-month LIBOR of 2.08% as of August 8, 2018, plus applicable rate under the Revolving Credit Facility, assuming current CenterPoint Energy Inc. issuer credit ratings.

In lieu of borrowings under the Bridge Facility and the Revolving Credit Facility, CenterPoint Energy intends to execute the Additional Financings described below prior to the close of the Vectren Merger:

Because the Additional Financings are contemplated to take place in the future, the pro forma financial statements were prepared in accordance with the accounting rules assuming that the Merger Consideration will be financed from drawings under the Bridge Facility and under the Revolving Credit Facility and through the proceeds from the issuance of the Series A Preferred Stock offered hereby. However, CenterPoint Energy currently does not intend to draw on the Bridge Facility or its Revolving Credit Facility but rather intends to fund the Merger Consideration with proceeds received through the Additional Financings, the proceeds from the issuance of the Series A Preferred Stock offered hereby and cash on hand, although there is no guarantee that CenterPoint Energy will be able to consummate the Additional Financings as planned or at all.

(4) Adjustments to Pro Forma Balance Sheet

The pro forma adjustments are based on our preliminary estimates and assumptions that are subject to change. The following adjustments have been reflected in the pro forma balance sheet:

S-35

S-36

S-37

(5) Adjustments to Pro Forma Statements of Income

S-38

(6) Reclassification Adjustments

CenterPoint Energy has completed a preliminary review of the financial statement presentation of Vectren for purposes of the unaudited pro forma condensed combined financial statements. During this review, the following financial statement reclassifications were performed in order to align the presentation of Vectren’s financial information with that of CenterPoint Energy: