Filed Pursuant to Rule 424(b)(5)
Registration No. 333-215833

The information in this preliminary prospectus supplement and the accompanying prospectus is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell these securities and are not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED SEPTEMBER 24, 2018

PRELIMINARY PROSPECTUS SUPPLEMENT

(To Prospectus Dated September 24, 2018)

$1,500,000,000

CenterPoint Energy, Inc.

Common Stock

We are offering $1,500,000,000 of shares of our common stock, par value $0.01 per share. Our common stock is listed on The New York Stock Exchange and The Chicago Stock Exchange, in each case, under the symbol “CNP.” The last reported sale price on The New York Stock Exchange of our common stock on September 21, 2018 was $28.03 per share.

Concurrently with this offering, we are offering (the “Concurrent Offering”), by means of a separate prospectus supplement, 15,000,000 depositary shares, each of which represents a 1/20th interest in a share of our     % Series B Mandatory Convertible Preferred Stock, $0.01 par value per share, which we refer to in this prospectus supplement as our Series B Preferred Stock (or up to 2,250,000 additional depositary shares if the underwriters in the Concurrent Offering exercise their option to purchase additional depositary shares to cover over-allotments, if any, in full), at a public offering price of $50.00 per depositary share. Completion of this offering of shares of our common stock is not contingent upon the completion of the Concurrent Offering and the completion of the Concurrent Offering is not contingent upon the completion of this offering.

Investing in our common stock involves risks. See “Risk Factors” beginning on page S-9 of this prospectus supplement and on page 3 of the accompanying prospectus.

We have granted the underwriters an option to purchase, exercisable within 30 days from the date of this prospectus supplement, up to an additional $225,000,000 of shares of our common stock to cover over-allotments, if any, at the public offering price, less the underwriting discount.

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 our common stock to investors on or about                     , 2018.

Joint Book-Running Managers

Prospectus Supplement dated September     , 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 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 our common 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 our common stock and are not soliciting an offer to buy our common 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.

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TABLE OF CONTENTS

Prospectus Supplement

We expect that delivery of the shares of our common stock offered hereby will be made against payment therefor on or about                     , 2018, which will be the third business day following the date of pricing of the shares of our common stock (this settlement cycle being referred to as “T+3”). 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 shares of our common stock on the initial pricing date of the shares of our common stock or the next succeeding business day will be required, by virtue of the fact that the shares of our common stock initially will settle in T+3, to specify alternative settlement arrangements at the time of any such trade to prevent a failed settlement and should consult their own advisors.

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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 (the “2017 Form 10-K”) and our Quarterly Reports on Form 10-Q for the quarterly periods ended March 31, 2018 and June 30, 2018 (the “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 our common stock.

Risks Related to the Vectren Merger

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 our common 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, exercising our option to redeem our Series B Preferred Stock and our corresponding depositary shares for cash, 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 shares of common stock offered hereby, the Concurrent Offering and the Series A Preferred Stock Offering, 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 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:

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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 enable CenterPoint Energy to pay dividends on its common stock, the Series A Preferred Stock, the Series B Preferred Stock or the depositary shares 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, Series A Preferred Stock, Series B Preferred Stock and depositary shares 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 common stock, Series B Preferred Stock, Series A Preferred Stock, depositary shares or other preferred stock, which may dilute the voting rights and/or economic interests of

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holders of our common 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 depositary shares, Series B Preferred Stock, Series A Preferred Stock or other preferred 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 the Concurrent Offering is not completed (or if this offering or the Concurrent Offering 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 the 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 $2.93 billion of additional indebtedness as part of the Merger Debt Financings, and if and to the extent the Concurrent Offering is not completed (for any reason, including satisfying all closing conditions, including regulatory requirements, faster than anticipated) or this offering or the Concurrent Offering are completed for less proceeds than anticipated, we would fund any shortfall with additional indebtedness, which may include borrowings under the Bridge Facility or the 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 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

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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 Merger Debt 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, through the proceeds from the Series A Preferred Stock Offering and the Concurrent Offering, and through the proceeds from the issuance of the shares of our common stock offered hereby. See “Unaudited Pro Forma Condensed Combined Financial Information.” However, we do not intend to draw on the Bridge Facility or the Revolving Credit Facility but rather intend to fund the Merger Consideration with proceeds received through the Merger Debt Financings, as well as cash on hand, in addition to the proceeds from the Series A Preferred Stock Offering and the Concurrent Offering, and the issuance of the shares of our common stock offered hereby, although there is no guarantee that we will be able to consummate the Concurrent Offering or the Merger Debt Financings as planned or at all. As a result, purchasers of shares of our common 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. The actual size and terms of, and amounts of proceeds we receive from this offering, the Concurrent Offering and the Merger Debt Financings will depend on, among other things, market conditions at the time of each financing and may differ, perhaps substantially, from the size, terms and amounts that we have assumed in the unaudited pro forma condensed combined financial information. Any changes in these assumptions would result in a change in the unaudited pro forma condensed combined financial information, which could be material. For example, if the number of shares of our common stock and our depositary shares we actually issue upon consummation of this offering and in the Concurrent Offering, respectively, exceeds the number of shares of our common stock and our depositary shares we have assumed for the purposes of the unaudited pro forma condensed combined financial information, this would reduce, perhaps substantially, the amount of pro forma earnings per common share reflected in such information. 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.

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

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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 do not intend to provide you with updated unaudited pro forma condensed combined financial information that reflects the actual number of shares of our common stock to be sold in this offering, the actual number of depositary shares to be sold in the Concurrent Offering, the actual public offering prices, the actual dividend rate on the Series B Preferred Stock or any of the other actual terms of this offering or the Concurrent Offering.

As a result of the foregoing, purchasers of shares of our common 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 Merger Debt Financings may have a material adverse effect on the market price of the shares of our common stock.

We expect to incur a substantial amount of additional indebtedness as part of the Merger Debt Financings. See “Summary — Recent Developments — Sources and Uses.” To the extent we incur indebtedness or issue debt securities as all or part of the Merger Debt 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. If we complete the Concurrent Offering, we may be permitted to redeem the Series B Preferred Stock and the corresponding depositary shares 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 Merger Debt 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 Merger Debt Financings. If we are required to redeem or repay any indebtedness or debt securities issued in the Merger Debt 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 Merger Debt 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 our depositary shares, or any indebtedness incurred or other securities issued as part of the Merger Debt Financings. It is possible that our failure to complete the Vectren Merger, or the expenditure of our funds to redeem or repay any Merger Debt Financings, may have a material adverse effect on the market price of the shares of our common stock.

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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 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. Vectren and the Vectren director defendants filed a motion to dismiss on August 15, 2018. On August 22, 2018, the court denied the interim lead plaintiffs’ preliminary injunction, which sought to halt the Vectren shareholder vote on the Vectren Merger. Pursuant to a stipulation entered on September 4, 2018, the case may proceed once the lead plaintiff (when appointed) files a consolidated amended complaint.

The outcome of this litigation is uncertain. If a dismissal is 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.

Risks Related to Ownership of Our Common Stock

Our ability to pay dividends on our common stock may be limited.

Our payment of dividends on our common stock in the future will be determined by our board of directors (or an authorized committee thereof) in its sole discretion and will depend on business conditions, our financial condition, earnings and liquidity, and other factors.

The agreements governing any future indebtedness of ours may limit our ability to pay cash dividends on our capital stock, including our common stock. In the event that the agreements governing any such indebtedness restrict our ability to pay dividends in cash on our common stock, we may be unable to pay dividends in cash on our common stock unless we can refinance the amounts outstanding under such agreements.

Additionally, except under limited circumstances, we will not declare or pay, or set aside for payment, dividends on any of our common stock unless full cumulative dividends have been or contemporaneously are being paid on all outstanding shares of our Series A Preferred Stock, Series B Preferred Stock and any other preferred stock that ranks senior to our common stock with respect to the payment of dividends, through the most recently completed respective dividend periods.

Under Texas law, our board of directors (or an authorized committee thereof) may authorize a dividend, and we may make a dividend, so long as (i) the dividend does not violate our articles of incorporation, (ii) we are not insolvent after the dividend and (iii) the dividend does not exceed our surplus (the amount by which our net

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assets exceed our stated capital). Further, even if we are permitted under our contractual obligations and Texas law to pay cash dividends on our capital stock, we may not have sufficient cash to pay dividends in cash on our common stock.

The common stock issuable upon conversion of our Series B Preferred Stock that may be issued in the Concurrent Offering, and the possibility of the sale of our common stock in the future, could reduce the market price of our common stock.

Concurrently with this offering, we are offering, by means of a separate prospectus supplement, 15,000,000 depositary shares, each representing a 1/20th ownership interest in a share of our Series B Preferred Stock (or up to 2,250,000 additional depositary shares if the underwriters of that offering exercise their option to purchase additional depositary shares to cover over-allotments, if any, in full), at a public offering price of $50.00 per depositary share. If issued, the shares of our Series B Preferred Stock represented by the depositary shares will be mandatorily convertible into an aggregate of up to              shares of our common stock (or up to              shares of our common stock if the underwriters in that offering exercise their option to purchase additional depositary shares to cover over-allotments, if any, in full), in each case, subject to anti-dilution, make-whole and other adjustments. Completion of this offering of our common stock is not contingent upon the completion of the Concurrent Offering and the completion of the Concurrent Offering is not contingent upon the completion of this offering. In the future, we may sell additional shares of our common stock and preferred stock to raise capital or acquire interests in other companies by using a combination of cash and our stock or just our stock. Any of these events may dilute your ownership interest in us and have an adverse impact on the price of our common stock. Furthermore, sales of a substantial amount of our common stock in the public market, or the perception that these sales may occur, could reduce the market price of our common stock. This could also impair our ability to raise additional capital through the sale of our securities.

The market price of our common stock may be volatile or may decline and it may be difficult for you to resell shares of our common stock at prices you find attractive.

The market price of our common stock has historically experienced and may continue to experience volatility. For example, during the twelve months ended August 31, 2018, the high sales price per share of our common stock on The New York Stock Exchange was $30.45 and the low sales price per share was $24.41. The price of our common stock could be subject to wide fluctuations in the future in response to the following events or factors:

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Other risks described elsewhere under “Risk Factors” in this prospectus supplement and the accompanying prospectus and in the documents incorporated by reference in this prospectus supplement also could materially and adversely affect the price of our common stock.

Anti-takeover provisions in our organizational documents and under Texas law may impede or discourage a takeover, which could cause the market price of our common stock to decline.

We are a Texas corporation, and the anti-takeover provisions of Texas law impose various impediments to the ability of a third party to acquire control of us, even if a change in control would be beneficial to our existing shareholders, which, under certain circumstances, could reduce the market price of our common stock. In addition, protective provisions in our articles of incorporation and our bylaws or the implementation by our board of directors of a shareholder rights plan could prevent a takeover, which could harm our shareholders.

If issued, our Series B Preferred Stock and our depositary shares may adversely affect the market price of our common stock.

The market price of our common stock is likely to be influenced by our Series B Preferred Stock and our depositary shares, in each case, if issued. For example, the market price of our common stock could become more volatile and could be depressed by:

Our common stock will rank junior to our Series A Preferred Stock and, if issued, our Series B Preferred Stock with respect to dividends and amounts payable in the event of our liquidation, dissolution or winding-up of our affairs.

Our common stock will rank junior to our Series A Preferred Stock and, if issued, our Series B Preferred Stock with respect to the payment of dividends and amounts payable in the event of our liquidation, dissolution or winding-up of our affairs. This means that, unless accumulated dividends have been paid or set aside for payment on all our outstanding Series A Preferred Stock and, if issued, our Series B Preferred Stock through the most recently completed dividend period, no dividends may be declared or paid on our common stock and we will not be permitted to repurchase any of our common stock, subject to limited exceptions. Likewise, in the event of our voluntary or involuntary liquidation, dissolution or winding-up of our affairs, no distribution of our assets may be made to holders of our common stock until we have paid to holders of our Series A Preferred Stock and our Series B Preferred Stock a liquidation preference equal to $1,000 per share plus accumulated and unpaid dividends.

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Holders of our Series A Preferred Stock and, if issued, our Series B Preferred Stock will have the right to elect two directors in the case of certain dividend arrearages.

If dividends on any shares of our Series A Preferred Stock or, if issued, our Series B Preferred Stock have not been declared and paid for the equivalent of three or more semi-annual or six or more quarterly dividend periods, whether or not for consecutive dividend periods, the holders of shares of our Series A Preferred Stock and, if issued, our Series B Preferred Stock, voting together as a single class with holders of any and all other series of our capital stock on a parity with our Series A Preferred Stock or our Series B Preferred Stock (as to the payment of dividends and amounts payable on a liquidation, dissolution or winding up of our affairs) upon which like voting rights have been conferred and are exercisable will be entitled to vote for the election of a total of two additional members of our board of directors, subject to certain terms and limitations. This right to elect directors will dilute the representation of the holders of our common stock on our board of directors and may adversely affect the market price of our common stock.

Our issuance of preferred stock may cause the price of our common stock to decline, which may negatively impact your investment.

Our board of directors is authorized to issue series of shares of preferred stock without any action on the part of the holders of our common stock. Our board of directors also has the power, without the approval of the holders of our common stock, to set the terms of any such series of shares of preferred stock that may be issued, including the designations, preferences, limitations and relative rights, voting, redemption and other rights over our common stock with respect to dividends or if we liquidate, dissolve or wind up our affairs and other terms. Our Series A Preferred Stock, our Series B Preferred Stock represented by the depositary shares we are offering in the Concurrent Offering and any other preferred stock we may issue in the future will rank senior to all of our common stock with respect to the payment of dividends or upon our liquidation, dissolution or winding up of our affairs. If we issue preferred stock in the future that has preference over common stock with respect to the payment of dividends or upon our liquidation, dissolution or winding up of our affairs, or if we issue preferred stock with voting rights that dilute the voting power of our common stock, the market price of our common stock could decrease, which may negatively impact your investment.

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 our common 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 our common 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 our common stock to participate in those assets, will be structurally subordinated to the claims of that subsidiary’s 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.

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USE OF PROCEEDS

We estimate that the net proceeds to us from this offering, after deducting issuance costs and discounts, will be approximately $             (or approximately $        if the underwriters exercise their option to purchase additional shares of our common stock to cover over-allotments, if any, in full).

In addition, we estimate that the net proceeds to us from the Concurrent Offering, after deducting issuance costs and discounts, will be approximately $             (or approximately $        if the underwriters in the Concurrent Offering exercise their option to purchase additional depositary shares to cover over-allotments, if any, in full).

We intend to use the net proceeds from this offering, the Series A Preferred Stock Offering, and if completed, the Concurrent Offering and the Merger Debt Financings, as well as cash on hand, 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, the Concurrent Offering or the Merger Debt Financings, and there can be no assurance that the Vectren Merger, the Concurrent Offering or any Merger Debt Financings will be consummated on the terms described herein or at all. If for any reason the proposed Vectren Merger has not closed at or prior to 5:00 p.m., New York City time, on April 21, 2019 or if certain acquisition termination events occur, then we expect to use the net proceeds from this offering, together with the net proceeds from the Concurrent Offering, for general corporate purposes, which may include, in our sole discretion, exercising our option to redeem our Series B Preferred Stock and our corresponding depositary shares for cash, 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.

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PRICE RANGE OF COMMON STOCK AND DIVIDENDS

As of September 21, 2018, our common stock was held by approximately 29,715 shareholders of record. Our common stock is listed on The New York Stock Exchange and The Chicago Stock Exchange, in each case, under the symbol “CNP.” The following table sets forth the high and low closing prices of our common stock on The New York Stock Exchange composite tape during the periods indicated, as reported by Bloomberg, and the cash dividends declared in these periods. As of September 19, 2018, there were 431,555,853 shares of our common stock outstanding, excluding any shares of our common stock issuable under our equity compensation plans.

The closing market price of our common stock on September 21, 2018 was $28.03 per share.

The amount of future cash dividends will be subject to determination based upon our results of operations and financial condition, our future business prospects, any applicable contractual restrictions and other factors that our board of directors considers relevant and will be declared at the discretion of our board of directors.

On July 26, 2018, we declared a regular quarterly cash dividend of $0.2775 per share, payable on September 13, 2018 to shareholders of record at the close of business on August 16, 2018.

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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 the incurrence of any indebtedness, including the issuance of debt securities and commercial paper in the Merger Debt Financings or drawing on the Bridge Facility or the 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 the 2017 Form 10-K and the 2nd Quarter 2018 Form 10-Q. Because the closing of this offering is not contingent upon the completion of the Concurrent Offering, you should not assume that the Concurrent Offering will occur.

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CONCURRENT OFFERING OF OUR DEPOSITARY SHARES

Concurrently with this offering, we are offering, by means of a separate prospectus supplement, 15,000,000 depositary shares, each representing a 1/20th ownership interest in a share of our Series B Preferred Stock (or up to 2,250,000 additional depositary shares if the underwriters in the Concurrent Offering exercise their option to purchase additional depositary shares to cover over-allotments, if any, in full), at a public offering price of $50.00 per depositary share. The shares of our Series B Preferred Stock represented by the depositary shares will be mandatorily convertible into an aggregate of up to                  shares of our common stock (or up to              shares of our common stock if the underwriters in that offering exercise their option to purchase additional depositary shares to cover over-allotments, if any, in full), in each case, subject to anti-dilution, make-whole and other adjustments.

We estimate that the net proceeds from the Concurrent Offering, after deducting issuance costs and discounts, will be approximately $        (or approximately $        if the underwriters in the Concurrent Offering exercise their option to purchase additional depositary shares to cover over-allotments, if any, in full). There can be no assurance that the Concurrent Offering will be completed. Completion of this offering of shares of our common stock is not contingent upon the completion of the Vectren Merger, the Concurrent Offering or upon the consummation of the Merger Debt Financings, and the completion of the Concurrent Offering is not contingent upon the completion of the Vectren Merger, this offering or upon the consummation of the Merger Debt Financings.

Our common stock will rank junior to our Series A Preferred Stock and, if issued, our Series B Preferred Stock with respect to the payment of dividends and amounts payable in the event of our liquidation, dissolution or winding up of our affairs. No dividends may be declared or paid on our common stock unless full cumulative dividends have been paid or set aside for payment on all our outstanding Series A Preferred Stock, and if issued, our Series B Preferred Stock, through the most recently completed dividend period. Likewise, in the event of our voluntary or involuntary liquidation, dissolution or winding up of our affairs, no distribution of our assets may be made to holders of our common stock until we have paid to holders of our Series A Preferred Stock and, if issued, our Series B Preferred Stock, a liquidation preference equal to $1,000 per share plus accumulated and unpaid dividends.

Because the closing of this offering is not contingent upon the completion of the Vectren Merger, Concurrent Offering or upon the consummation of the Merger Debt Financings, you should not assume that Vectren Merger, the Concurrent Offering, or the Merger Debt Financings will take place.

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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 following the Vectren Merger.

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 close of 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, Morgan Stanley Senior Funding, Inc. and a syndicate of lenders. Any borrowings under the Bridge Facility would be classified as short-term debt in current liabilities. As a result of the issuance of 800,000 shares of CenterPoint Energy’s Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Stock (Series A Preferred Stock) with gross proceeds of $800 million on August 22, 2018, the commitments under the Bridge Facility were reduced to approximately $4.2 billion.

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For purposes of the pro forma financial statements, CenterPoint Energy has assumed the receipt of gross proceeds from the following transactions (one of which has been completed) to fund, after payment of issuance costs and discounts, the approximately $6.0 billion cash consideration Vectren Merger purchase price (see Note 3 for further details):

However, in lieu of drawing on the Bridge Facility and the Revolving Credit Facility, CenterPoint Energy anticipates financing the portion of the Vectren Merger reflected for those instruments above with debt securities and/or commercial paper, subject to then current market conditions, as well as with cash on hand. CenterPoint Energy’s permanent financing assumptions for debt securities and commercial paper (together, Merger Debt Financings) are detailed in the accompanying notes but are not reflected in the pro forma statements of income or pro forma balance sheet.

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 based 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.

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CENTERPOINT ENERGY, INC.

UNAUDITED PRO FORMA CONDENSED COMBINED BALANCE SHEET

June 30, 2018

See Notes to Unaudited Pro Forma Condensed Combined Financial Statements

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CENTERPOINT ENERGY, INC.

UNAUDITED PRO FORMA CONDENSED COMBINED BALANCE SHEET — (continued)

June 30, 2018

See Notes to Unaudited Pro Forma Condensed Combined Financial Statements

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CENTERPOINT ENERGY, INC.

UNAUDITED PRO FORMA CONDENSED COMBINED STATEMENTS OF INCOME

For the Six Months Ended June 30, 2018

See Notes to Unaudited Pro Forma Condensed Combined Financial Statements

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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

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CENTERPOINT ENERGY, INC.

NOTES TO UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL STATEMENTS

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 (i) directly attributable to the Vectren Merger, (ii) factually supportable and (iii) 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 revenues 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 comprised 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

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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.

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.

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 could 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):

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This preliminary purchase price allocation has been used to prepare pro forma adjustments in the pro forma balance sheet and pro forma statements of income. 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 and, as such, no assurances can be provided regarding the preliminary purchase accounting. 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.

CenterPoint Energy sometimes refers to the planned issuance of its Common Stock and Series B Preferred Stock, together with its completed issuance of the Series A Preferred Stock, as its Merger Equity Financings. CenterPoint Energy sometimes refers to the planned issuance of debt securities and commercial paper as its Merger Debt Financings. The actual size and terms of, and amounts of proceeds CenterPoint Energy receives from, its respective Merger Equity Financings and Merger Debt Financings (collectively, Merger Financings) will depend on, among other things, market conditions at the time of each Merger Financing 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.

For purposes of the pro forma financial statements, CenterPoint Energy has assumed the receipt of gross proceeds from the following transactions (one of which has been completed) to fund, after payment of issuance costs and discounts, the approximately $6.0 billion cash consideration Vectren Merger purchase price further described below:

However, in lieu of drawing on the Bridge Facility and the Revolving Credit Facility, CenterPoint Energy anticipates financing the portion of the Vectren Merger reflected for those instruments above with its Merger Debt Financings, subject to then current market conditions, as well as with cash on hand. CenterPoint Energy’s permanent financing assumptions for its Merger Debt Financings are detailed below but are not reflected in the pro forma statements of income or pro forma balance sheet.

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. As a result of the issuance of 800,000 shares of CenterPoint Energy’s Series A Preferred Stock with gross proceeds of $800 million on August 22, 2018, the commitments under the Bridge Facility were reduced to approximately $4.2 billion. For purposes of the pro forma financial statements, CenterPoint Energy’s assumed borrowings under the Bridge Facility were reduced to $1.95 billion due to its Merger Equity Financings. For purposes of the pro forma financial statements, CenterPoint Energy has assumed a weighted-average interest rate of 5.4%, which includes duration and drawn fees on the $1.95 billion Bridge Facility borrowings. Drawn fees are estimated based on current 1-month LIBOR of 2.17% as of September 19, 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 CenterPoint Energy’s 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’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,

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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.

On August 22, 2018, CenterPoint Energy completed the issuance of 800,000 shares of its Series A Preferred Stock for $790 million, net of $10 million of issuance costs and discounts, with an aggregate liquidation value of $800 million. The Series A Preferred Stock accrue dividends in cash, calculated as a percentage of the aggregate liquidation value, at a fixed annual rate of 6.125% per annum to, but excluding, September 1, 2023, and at an annual rate of 3-month LIBOR plus a spread of 3.270% thereafter.

For purposes of the pro forma financial statements, CenterPoint Energy has presented its planned issuance of 750,000 shares of its Series B Preferred Stock for $729 million, net of $21 million of issuance costs and discounts, with an aggregate liquidation value of $750 million and a per share liquidation value of $1,000. Each share of Series B Preferred Stock will be represented by 20 depositary shares offered and sold to the public. At the mandatory conversion date, each outstanding share of Series B Preferred Stock will be converted into a variable number of shares of Common Stock, depending on the preceding 20-day volume-weighted-average-price of Common Stock and subject to possible adjustment pursuant to the terms of the Series B Preferred Stock. CenterPoint Energy may pay dividends on the Series B Preferred Stock in cash or shares of Common Stock, calculated as a percentage of the aggregate liquidation value, at an assumed rate of 7.00% per annum. This assumed dividend rate is based on current market conditions. The actual terms, including but not limited to, dividend rate, shares issued (including as a result of any exercise of the underwriters’ option) and conversion rate, on the Series B Preferred Stock at the time of issuance may differ, perhaps substantially, from the assumptions CenterPoint Energy has applied in these pro forma financial statements.

Additionally, for purposes of the pro forma financial statements, CenterPoint Energy has presented its planned issuance of 54 million shares of its Common Stock for $1.458 billion, net of $42 million of issuance costs and discounts, with an aggregate value of $1.5 billion, and that those shares will be issued at an assumed public offering price of $27.91 per share. This assumed issuance price is based on the closing price of Common Stock as traded on the New York Stock Exchange on September 19, 2018. The actual terms, including but not limited to, issuance price or shares issued (including as a result of any exercise of the underwriters’ option), of the Common Stock at the time it is issued may differ, perhaps substantially, from the assumptions CenterPoint Energy has applied in these pro forma financial statements.

In May 2018, CenterPoint Energy entered into an amendment to its Revolving Credit Facility that will increase the aggregate commitments from $1.7 billion to $3.3 billion 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 $1.064 billion under the Revolving Credit Facility at a weighted-average interest rate of 3.7%. 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 2.17% as of September 19, 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 consummate its Merger Debt Financings aggregating approximately $2.95 billion, net of issuance costs of $20 million, with an assumed weighted-average interest rate (including the index rate plus a credit spread) of 4.00% per annum. This assumed rate is based on borrowing costs for debt securities and commercial paper under current market conditions, presently expected to range from approximately 2.30% for commercial paper to up to 4.65% for senior notes. The actual interest rate and original issue discount on the Merger Debt Financings will be

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based on market conditions at the time the commercial paper and senior notes are issued and may differ, perhaps substantially, from the rate and discount assumed for purposes of the pro forma financial statements. Furthermore, any cash on hand may be used to reduce the Merger Debt Financings incurred to finance the Vectren Merger.

Because the Merger Debt 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 purchase price in excess of the Merger Equity Financings will be financed from drawings under the Bridge Facility and under the Revolving Credit Facility. However, CenterPoint Energy currently does not intend to draw on the Bridge Facility or its Revolving Credit Facility but rather intends to fund the portion of the Vectren Merger purchase price reflected for those instruments with proceeds received through the Merger Debt Financings and cash on hand, although there is no guarantee that CenterPoint Energy will be able to consummate the Merger Debt Financings as planned or at all.

The pro forma adjustments are based on our preliminary estimates and assumptions that are subject to change. The pro forma adjustments are based upon available information and certain assumptions that management believes are reasonable. The following adjustments have been reflected in the pro forma balance sheet:

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In addition, if the underwriters exercise in full their option to purchase an additional 2.25 million depositary shares representing Series B Preferred Stock, it would result in an additional $113 million of proceeds, subject to issuance costs and discounts. However, no such exercise is reflected in these pro forma financial statements.