Pfizer (PFE) 424B3Prospectus supplement

Filed Pursuant to Rule 424(b)(3)
Registration No. 333-223221

The information contained in this preliminary prospectus supplement is not complete and may be changed. A registration statement relating to these securities is effective. 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 May 18, 2020

PRELIMINARY PROSPECTUS SUPPLEMENT

(To Prospectus dated February 26, 2018)

Pfizer Inc.

$             % NOTES DUE 2025

$             % NOTES DUE 2030

$             % NOTES DUE 2040

$             % NOTES DUE 2050

The 2025 notes (the “2025 notes”) will mature on         , 2025, the 2030 notes (the “2030 notes”) will mature on                , 2030, the 2040 notes (the “2040 notes”) will mature on                     , 2040 and the 2050 notes (the “2050 notes”) will mature on                , 2050. We refer to the 2025 notes, the 2030 notes, the 2040 notes and the 2050 notes collectively as the “notes.” The notes will be our unsecured and unsubordinated debt obligations and will not have the benefit of any sinking fund. The notes will rank equally with all other unsubordinated indebtedness of Pfizer from time to time outstanding. Interest on the notes will be payable semi-annually in arrears on        and        of each year, beginning on        , 2020. The notes of each series are redeemable in whole or in part at our option at the redemption prices set forth in this prospectus supplement.

Investing in the notes involves risks. See “Risk Factors” beginning on pageS-4 of this prospectus supplement and beginning on page 21 of our Annual Report on Form10-K for the year ended December 31, 2019, as well as the risk factors relating to our business contained in documents we file with the U.S. Securities and Exchange Commission (the “SEC”) which are incorporated by reference into this prospectus supplement and the accompanying prospectus.

Neither the SEC 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 notes through the facilities of The Depository Trust Company (“DTC”) for the accounts of its direct participants, including Clearstream Banking,société anonymeand Euroclear Bank S.A./N.V., as operator of the Euroclear System, against payment therefor in New York, New York on or about            , 2020.

Joint Book-Running Managers

TABLE OF CONTENTS

PROSPECTUS SUPPLEMENT

PROSPECTUS

No person is authorized to give any information or to make any representations other than those contained or incorporated by reference in this prospectus supplement or the accompanying prospectus and any free writing prospectus we may provide you in connection with this offering. 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. This prospectus supplement and the accompanying prospectus are not an offer to sell or the solicitation of an offer to buy any securities in any jurisdiction where it is unlawful. Neither the delivery of this prospectus supplement or the accompanying prospectus, nor any sale of notes made under these documents, will, under any circumstances, create any implication that there has been no change in our affairs since the date of this prospectus supplement, the accompanying prospectus or any free writing prospectus we may provide you in connection with this offering or that the information contained or incorporated by reference is correct as of any time subsequent to the date of such information. You should assume that the information in this prospectus supplement and the accompanying prospectus, as well as the information incorporated by reference in this prospectus supplement and the accompanying prospectus, is accurate only as of the date of the documents containing the information, unless the information specifically indicates that another date applies. Our business, financial condition, results of operations and prospects may have changed since those dates.

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This document is in two parts. The first is this prospectus supplement, which describes the specific terms of this offering. The second part, the accompanying prospectus, contains a description of our debt securities and gives more general information, some of which may not apply to this offering. This prospectus supplement also adds to, updates and changes information contained in the accompanying prospectus. If the description of the offering varies between this prospectus supplement and the accompanying prospectus, you should rely on the information in this prospectus supplement. The accompanying prospectus is part of a registration statement that we filed with the SEC using a shelf registration statement. Under the shelf registration process, from time to time, we may offer and sell securities in one or more offerings.

References in this prospectus supplement to “Pfizer,” the “Company,” “we,” “us” and “our” are to Pfizer Inc. and its consolidated subsidiaries unless otherwise stated or the context so requires.

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CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This prospectus supplement and the accompanying prospectus, as well as the information incorporated by reference in this prospectus supplement and the accompanying prospectus, may include forward-looking statements made within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). Such forward-looking statements involve substantial risks and uncertainties. We have tried, wherever possible, to identify such statements by using words such as “will,” “may,” “could,” “likely,” “ongoing,” “anticipate,” “estimate,” “expect,” “project,” “intend,” “plan,” “believe,” “assume,” “target,” “forecast,” “guidance,” “goal,” “objective,” “aim,” “seek” and other words and terms of similar meaning or by using future dates in connection with any discussion of, among other things, our anticipated operating and financial performance, business plans and prospects, expectations for our product pipeline,in-line products and product candidates, including anticipated regulatory submissions, data read-outs, study starts, approvals, revenue contribution, growth, performance, timing of exclusivity and potential benefits, strategic reviews, capital allocation objectives, plans for and prospects of our acquisitions and other business-development activities, benefits anticipated from the reorganization of our commercial operations in 2019, sales efforts, expenses, interest rates, foreign exchange rates, the outcome of contingencies, such as legal proceedings, government regulation, our ability to successfully capitalize on growth opportunities or prospects, manufacturing and product supply, our efforts to respond toCOVID-19, our expectations regarding the impact ofCOVID-19 on our business, operations and financial results and plans relating to share repurchases and dividends.

A list and description of risks, uncertainties and other matters can be found in our Annual Report on Form10-K for the year ended December 31, 2019 and in our Quarterly Report on Form10-Q for the quarterly period ended March 29, 2020, in each case including in the sections thereof captioned “Forward-Looking Information and Factors That May Affect Future Results” and “Risk Factors,” in our Current Reports on Form8-K, and in this prospectus supplement and accompanying prospectus, in each case including in the section thereof captioned “Risk Factors.” You should understand that it is not possible to predict or identify all such factors. Consequently, you should not consider any such list to be a complete set of all potential risks or uncertainties.

We cannot guarantee that any forward-looking statement will be realized. Achievement of anticipated results is subject to substantial risks, uncertainties and inaccurate assumptions. Should known or unknown risks or uncertainties materialize, or should underlying assumptions prove inaccurate, actual results could vary materially from past results and those anticipated, estimated or projected. You should bear this in mind as you consider forward-looking statements, and you are cautioned not to put undue reliance on forward-looking statements.

We undertake no obligation to publicly update forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law or by the rules and regulations of the SEC. You are advised, however, to consult any further disclosures we make on related subjects in our Form10-K,10-Q and8-K reports and our other filings with the SEC.

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RISK FACTORS

Before purchasing the notes, you should consider carefully the information under the headings “Risk Factors” in our Annual Report on Form10-K for the year ended December 31, 2019 and our Quarterly Report on Form10-Q for the quarterly period ended March 29, 2020 and the following risk factors. You should also carefully consider the other information included in this prospectus supplement, the accompanying prospectus and other information incorporated by reference herein and therein. Each of the risks described in these documents could materially and adversely affect our business, financial condition, results of operations and prospects, and could result in a partial or complete loss of your investment. See “Where You Can Find More Information.”

The notes are unsecured and will be effectively junior to our secured indebtedness to the extent of the collateral therefor.

The notes are our unsecured general obligations. Holders of our secured indebtedness, if any, will have claims that are prior to your claims as holders of the notes, to the extent of the assets securing such indebtedness. Thus, in the event of a bankruptcy, liquidation, dissolution, reorganization or similar proceeding, our pledged assets would be available to satisfy obligations of our secured indebtedness before any payment could be made on the notes. To the extent that such assets cannot satisfy in full our secured indebtedness, the holders of such indebtedness would have a claim for any shortfall that would rank equally in right of payment with the notes. In any of the foregoing events, we cannot assure you that there will be sufficient assets to pay amounts due on the notes. As a result, holders of the notes may receive less, ratably, than holders of our secured indebtedness. At March 29, 2020, Pfizer Inc. had no secured indebtedness.

Active trading markets may not develop for the notes and the notes may trade at a discount from their initial offering price.

The notes are new issuances of securities for which no public trading markets currently exist. Although the underwriters have informed us that they intend to make markets in the notes, they are not obligated to do so, and any such market-making activities may be discontinued at any time without notice. Accordingly, liquid markets for the notes may not develop or be maintained. The notes will not be listed on any national securities exchange or be quoted on any automated dealer quotation system.

In addition, subsequent to their initial issuance, the notes may trade at a discount from their initial offering prices, depending upon prevailing interest rates, the markets for similar notes, our performance and other factors. The markets for the notes may not be free from disruptions that may adversely affect the prices at which you may sell the notes.

Holders of the notes will be structurally subordinated to our subsidiaries’ third-party indebtedness and obligations.

The notes are obligations of Pfizer Inc. exclusively and not of any of our subsidiaries. A significant portion of our operations is conducted through our subsidiaries. Our subsidiaries are separate legal entities that have no obligation to pay any amounts due under the notes or to make any funds available therefor, whether by dividends, loans or other payments. Except to the extent we are a creditor with recognized claims against our subsidiaries, all claims of third-party creditors (including trade creditors) and holders of preferred stock, if any, of our subsidiaries will have priority with respect to the assets of such subsidiaries over the claims of our creditors, including holders of the notes. Consequently, the notes will be structurally subordinated to all existing and future liabilities of any of our subsidiaries and any subsidiaries that we may in the future acquire or establish. As of March 29, 2020, our wholly-owned subsidiaries had aggregate borrowings under lines of credit and outstanding debt securities of approximately $6.3 billion.

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Our business, operations and financial condition and results have been and may continue to be adversely impacted by theCOVID-19 pandemic.

Our business, operations and financial condition and results have been impacted by theCOVID-19 pandemic to varying degrees, which we currently expect to primarily impact the second quarter of 2020. The pandemic presents a number of challenges for our business, including, among others, impacts due to travel limitations and government-mandated work-from-home orshelter-in-place orders; manufacturing disruptions and delays; supply chain interruptions, including challenges related to reliance on third-party suppliers; disruptions to pipeline development and clinical trials, including difficulties or delays in enrollment of certain clinical trials; decreased product demand, including due to reduced numbers ofin-person meetings with prescribers, patient visits with physicians, vaccinations and elective surgeries as well as increased unemployment resulting in lower new prescriptions or refills of existing prescriptions; challenges presented by reallocating human capital, R&D, manufacturing and other resources to assist in responding to the pandemic without disruption to our operations; costs associated with theCOVID-19 pandemic, including protocols intended to reduce the risk of transmission; increased supply chain costs and additional R&D costs incurred in our effort to develop a vaccine or treatment forCOVID-19; challenges as it relates to our business development initiatives, including potential delays or disruptions related to regulatory approvals, including related to the anticipated combination of Upjohn with Mylan; interruptions or delays in the operations of certain regulatory authorities, which may delay the approvals of new products we are developing, potential label expansions for existing products and the launch of newly-approved products; challenges related to our intellectual property, both domestically and internationally, including in response to any pressure or legal or regulatory action, by various stakeholders or governments that potentially results in us not seeking intellectual property protection for, licensing or agreeing not to enforce our intellectual property rights related to our medicines, including potential vaccines and treatments forCOVID-19; and other challenges presented by disruptions to our normal operations in response to the pandemic, as well as uncertainties regarding the duration and severity of the pandemic and its impacts and government or regulatory actions to contain the virus or control the supply of medicines.

We also face uncertainties related to our efforts to develop a potential treatment or vaccine forCOVID-19, including uncertainties related to the risk that our development programs may not be successful, commercially viable or receive approval from regulatory authorities; disruptions in the relationships between us and our collaboration partners or third-party suppliers; the risk that other companies may produce superior or competitive products; the risk that demand for any products we may develop may no longer exist; risks related to the availability of raw materials to manufacture any such products; the risk that we may not be able to recoup costs associated with our R&D and manufacturing efforts and risks associated with any changes in the way we approach or provide additional research funding for potential drug development related toCOVID-19; the risk that we may not be able to create or scale up manufacturing capacity on a timely basis or have access to logistics or supply channels commensurate with global demand for any potential approved vaccine or product candidate; and pricing and access challenges for such products, including in the U.S.

Further, theCOVID-19 pandemic, and the volatile global economic conditions stemming from the pandemic, could precipitate or amplify the other risk factors that we identify in the “Risk Factors” section of our Annual Report on Form10-K for the year ended December 31, 2019, which could materially adversely affect our business, operations and financial condition and results.

We are continuing to monitor the latest developments regarding theCOVID-19 pandemic on our business, operations and financial condition and results, and have made certain assumptions regarding the pandemic for purposes of our operational planning and financial projections, including assumptions regarding the duration and severity of the pandemic and the global macroeconomic impact of the pandemic. Despite careful tracking and planning, however, we are unable to accurately predict the extent of the impact of the pandemic on our business, operations and financial condition and results due to the uncertainty of future developments. In particular, we believe the ultimate impact on our business, operations and financial condition and results will be affected by the speed and extent of the continued spread of the coronavirus globally, the duration of the pandemic, new

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information that may emerge concerning the severity and incidence ofCOVID-19, the safety, efficacy and availability of a vaccine and treatments forCOVID-19, the global macroeconomic impact of the pandemic and governmental or regulatory actions to contain the virus or control supply of medicines. However, the pandemic may also affect our business, operations or financial condition and results in a manner that is not presently known to us or that we currently do not consider to present significant risks.

We regularly evaluate, engage in preliminary discussions concerning, and, where appropriate, execute on growth opportunities, although we cannot predict whether we will enter into any such transaction and, if so, the terms or financing needs in connection therewith.

We are committed to capitalizing on growth opportunities by advancing our own pipeline and maximizing the value of ourin-line products, as well as through various forms of business development, which can include alliances, licenses, joint ventures, collaborations, equity- or debt-based investments, dispositions, divestitures, mergers and acquisitions. We regularly evaluate, engage in preliminary discussions concerning, and, where appropriate, execute on these opportunities, although we cannot predict whether we will enter into any such transaction and, if so, the terms or financing needs in connection therewith. Pursuing these opportunities may require us to obtain additional equity or debt financing, could result in increased leverage and/or result in a downgrade of our credit ratings.

For example, on July 29, 2019, we announced that we entered into a definitive agreement to combine Mylan N.V. with Upjohn, our primarilyoff-patent and generic established medicines business, to create a new global pharmaceutical company, Viatris, which is expected to close in the second half of 2020. Additionally, on July 31, 2019, we completed the transaction in which we and GlaxoSmithKline plc combined our respective consumer healthcare businesses into a new consumer healthcare joint venture that operates globally under the GSK Consumer Healthcare name.

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USE OF PROCEEDS

We expect to receive net proceeds from this offering of $        (after deducting underwriting discounts, but before deducting expenses of the offering). We intend to use the net proceeds for general corporate purposes, including to repay a portion of our outstanding commercial paper and to refinance, redeem or repurchase existing debt. As of May 1, 2020, we had approximately $14.3 billion of commercial paper outstanding with a weighted average annual interest rate of 1.43% and a weighted average maturity of 66 days.

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DESCRIPTION OF NOTES

Each series of notes is a series of debt securities described in the accompanying prospectus. Reference should be made to the accompanying prospectus for a detailed summary of additional provisions of the notes and of the indenture, dated as of September 7, 2018, between Pfizer Inc. and The Bank of New York Mellon, as trustee, which we refer to as the “base indenture,” as supplemented by the fourth supplemental indenture to be dated as of                 , 2020, between Pfizer Inc. and The Bank of New York Mellon, as trustee, which we refer to as the “fourth supplemental indenture.” When we refer to the “indenture,” we mean the base indenture as supplemented by the fourth supplemental indenture. The following description is a summary of selected portions of the base indenture and the fourth supplemental indenture. It does not restate the base indenture or the fourth supplemental indenture, and those documents, not this description, define your rights as a holder of the notes.

References in this section to “Pfizer,” “we,” “us” and “our” are to Pfizer Inc., unless otherwise stated or the context so requires. The provisions described in the accompanying prospectus under the heading “Description of Debt Securities—Defeasance” will apply to the notes.

Principal, Maturity and Interest

The 2025 notes will initially be limited to $        aggregate principal amount, the 2030 notes will initially be limited to $        aggregate principal amount, the 2040 notes will initially be limited to $                 aggregate principal amount and the 2050 notes will initially be limited to $        aggregate principal amount. The 2025 notes will mature on        , 2025, the 2030 notes will mature on        , 2030, the 2040 notes will mature on                 , 2040 and the 2050 notes will mature on        , 2050. We will issue the notes in denominations of $2,000 and in integral multiples of $1,000 in excess of $2,000.

Interest on the 2025 notes will accrue at the annual rate of         %, interest on the 2030 notes will accrue at the annual rate of     %, interest on the 2040 notes will accrue at an annual rate of         % and interest on the 2050 notes will accrue at the annual rate of         %. Interest on the notes will accrue from and including        , 2020, and is payable on        and        of each year, beginning on        , 2020. Interest on the notes will be computed on the basis of a360-day year comprised of twelve30-day months.

We will make each interest payment to the holders of record of the notes at the close of business on the          or immediately preceding the relevant interest payment date.

The trustee, through its corporate trust office in the Borough of Manhattan, City of New York (in such capacity, the “paying agent”) will act as our paying agent with respect to the notes. Payments of principal, interest and premium, if any, will be made by us through the paying agent to DTC as described under “—Book-Entry System.”

Priority

The notes will be unsecured general obligations of Pfizer and will rank equally with all other unsubordinated indebtedness of Pfizer from time to time outstanding.

No Listing

The notes will not be listed on any national securities exchange or be quoted on any automated dealer quotation system.

Covenants

The indenture contains a provision that restricts our ability to consolidate with or merge into any other person or convey or transfer our properties and assets as an entirety or substantially as an entirety to any other person.

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The indenture does not restrict our ability to convey or transfer our properties and assets other than as an entirety or substantially as an entirety to any other person. See “Description of Debt Securities—Consolidation, Merger or Sale” in the accompanying prospectus. The indenture contains no other restrictive covenants, including those that would afford holders of the notes protection in the event of a highly-leveraged transaction involving Pfizer or any of its affiliates or other events involving us that may adversely affect our creditworthiness or the value of the notes. The indenture also does not contain any covenants relating to total indebtedness, interest coverage, stock repurchases, recapitalizations, dividends and distributions to shareholders, current ratios or acquisitions and divestitures. The notes will not have the benefit of covenants that relate to subsidiary guarantees, liens and sale leaseback transactions that apply to other of our existing unsecured and unsubordinated notes.

Further Issuances

Pfizer may, without the consent of the holders of notes of any series, issue additional notes having the same priority in right of payment and the same interest rate, maturity and other terms as the notes of such series (except for the issue date and the public offering price). Any additional notes having such similar terms, together with the notes of the applicable series, will constitute a single series of debt securities under the indenture. No additional notes of any series may be issued if an event of default has occurred with respect to the notes of such series. Pfizer will not issue any additional notes intended to form a single series with the notes of any series, unless such further notes will be fungible with all notes of such series for U.S. federal income tax purposes.

Optional Redemption; No Sinking Fund

At our option, we may redeem the notes of a series, in whole, at any time, or in part, from time to time, prior to the applicable Par Call Date (as defined below) at a redemption price equal to the greater of the following amounts:

plus, in each case, accrued and unpaid interest on the 2025 notes, the 2030 notes, the 2040 notes and the 2050 notes being redeemed to, but excluding, the redemption date.

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At any time on or after the Par Call Date applicable to a series of notes, we may redeem such notes, in whole or in part, at a redemption price equal to 100% of the principal amount of the notes to be redeemed,plus in each case, accrued and unpaid interest on the notes being redeemed to, but excluding, the redemption date.

Notwithstanding the foregoing, installments of interest on the applicable notes that are due and payable on interest payment dates falling on or prior to a redemption date will be payable on the interest payment date to the registered holders as of the close of business on the relevant record date according to the applicable notes and the indenture. The redemption prices for the notes will be calculated on the basis of a360-day year consisting of twelve30-day months.

We will mail notice of any redemption at least 10 days, but not more than 60 days, before the redemption date to each registered holder of the notes to be redeemed. Once notice of redemption is mailed, the notes called for redemption will become due and payable on the redemption date at the applicable redemption price,plus accrued and unpaid interest applicable to such notes to, but excluding, the redemption date.

Any redemption notice may, at our discretion, be subject to one or more conditions precedent, including completion of a corporate transaction. In such event, the related notice of redemption shall describe each such condition and, if applicable, shall state that, at our discretion, the date of redemption may be delayed until such time (including more than 60 days after the notice of redemption was given) as any or all such conditions shall be satisfied or waived, or such redemption may not occur and such notice may be rescinded in the event that any or all such conditions shall not have been satisfied (or waived by the Company in its sole discretion) by the date of redemption, or by the date of redemption as so delayed.

For purposes of the foregoing discussion, the following definitions apply:

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

“Comparable Treasury Price” means, with respect to any redemption date and series of notes to be redeemed, (A) the average of the Reference Treasury Dealer Quotations for such redemption date and series, after excluding the highest and lowest of such Reference Treasury Dealer Quotations, or (B) if the Independent Investment Banker obtains fewer than four such Reference Treasury Dealer Quotations, the average of such Reference Treasury Dealer Quotations, or (C) if only one Reference Treasury Dealer Quotation is received, such Reference Treasury Dealer Quotation.

“Independent Investment Banker” means one of the Reference Treasury Dealers appointed by us to act as the “Independent Investment Banker.”

“Par Call Date” means:

“Reference Treasury Dealer” means each of Barclays Capital Inc., Citigroup Global Markets Inc., Deutsche Bank Securities Inc. and J.P. Morgan Securities LLC (or their respective affiliates that are Primary Treasury Dealers), and their respective successors;provided, however, that if any of the foregoing shall cease to be a primary U.S. Government securities dealer in the United States (a “Primary Treasury Dealer”), we will substitute therefor another Primary Treasury Dealer.

“Reference Treasury Dealer Quotation” means, with respect to each Reference Treasury Dealer and any redemption date and series of notes to be redeemed, the average, as determined by the Independent Investment

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Banker, of the bid and asked prices for the Comparable Treasury Issue for such series (expressed in each case as a percentage of its principal amount) quoted in writing to the Independent Investment Banker by such Reference Treasury Dealer at 5:00 p.m. (New York City Time) on the third business day preceding such redemption date.

“Treasury Rate” means, with respect to any redemption date for any series of notes, the rate per annum equal to the semi-annual equivalent yield to maturity of the applicable Comparable Treasury Issue, assuming a price for such Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the applicable Comparable Treasury Price for such redemption date.

On and after the redemption date, interest will cease to accrue on the notes or any portion of the notes called for redemption (unless we default in the payment of the redemption price and accrued and unpaid interest). On or before the redemption date, we will deposit with a paying agent (or the trustee) money sufficient to pay the redemption price of and accrued and unpaid interest on the notes to be redeemed on that date. If fewer than all of the notes of a series are to be redeemed, the notes to be redeemed shall be selected pro rata, by lot or by such other method as the trustee shall deem fair and appropriate.

The notes are not entitled to the benefit of a sinking fund.

Book-Entry System

The Depository Trust Company (“DTC”), New York, New York, will act as securities depositary for the notes. Each series of notes will be issued as fully registered securities registered in the name of Cede & Co. (DTC’s partnership nominee) or such other name as may be requested by an authorized representative of DTC. One or more fully-registered global note certificates will be issued for each series of notes, in the aggregate principal amount of such issue, and will be deposited with DTC.

Beneficial interests in the notes will be shown on, and transfers thereof will be effected only through, records maintained by DTC and its direct and indirect participants, including Euroclear Bank S.A./N.V., as operator of the Euroclear System (“Euroclear”) and Clearstream Banking, société anonyme, Luxembourg (“Clearstream Banking”). Investors may elect to hold interests in the notes through any of DTC, Euroclear or Clearstream Banking, if they are participants in these systems, or indirectly through organizations which are participants in these systems. Euroclear and Clearstream Banking hold securities on behalf of their participants through customers’ securities accounts in their respective names on the books of their respective depositaries, which in turn hold the securities in customers’ securities accounts in the depositaries’ names on the books of DTC.

DTC has informed us that DTC is:

Euroclear and Clearstream Banking have informed us that: Euroclear and Clearstream Banking each hold securities for their customers and facilitate the clearance and settlement of securities transactions by electronic book-entry transfer between their respective account holders. Euroclear and Clearstream Banking provide various services including safekeeping, administration, clearance and settlement of internationally traded securities and securities lending and borrowing. Euroclear and Clearstream Banking also deal with domestic securities markets in several countries through established depositary and custodial relationships. Euroclear and Clearstream Banking have established an electronic bridge between their two systems across which their respective participants may settle trades with each other.

Euroclear and Clearstream Banking customers are world-wide financial institutions including underwriters, securities brokers and dealers, banks, trust companies and clearing corporations. Indirect access to Euroclear and Clearstream Banking is available to other institutions, which clear through or maintain a custodial relationship with an account holder of either system.

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DTC holds securities that its participants (“Direct Participants”) deposit with DTC. DTC also facilitates the settlement among Direct Participants of securities transactions, such as transfers and pledges, in deposited securities through electronic computerized book-entry changes in Direct Participants’ accounts, which eliminates the need for physical movement of securities certificates. Direct Participants include securities brokers and dealers, banks, trust companies, clearing corporations, and certain other organizations. DTC is a wholly-owned subsidiary of The Depository Trust & Clearing Corporation (“DTCC”). DTCC is the holding company for DTC, National Securities Clearing Corporation and Fixed Income Clearing Corporation, all of which are registered clearing agencies. DTCC is owned by the users of its regulated subsidiaries. Access to the DTC system is also available to others such as securities brokers and dealers, banks, and trust companies that clear through or maintain a custodial relationship with a Direct Participant, either directly or indirectly (“Indirect Participants”). The rules applicable to DTC and its Direct and Indirect Participants are on file with the SEC.

Purchases of notes under the DTC system must be made by or through Direct Participants, which receive a credit for the notes on DTC’s records. The ownership interest of each actual purchaser of each note (“Beneficial Owner”) is in turn to be recorded on the Direct and Indirect Participants’ records. Beneficial Owners will not receive written confirmations from DTC of their purchase, but Beneficial Owners are expected to receive written confirmations providing details of the transaction, as well as periodic statements of their holdings, from the Direct or Indirect Participant through which the Beneficial Owner entered into the transaction. Transfers of ownership interests in the notes are to be accomplished by entries made on the books of Direct and Indirect Participants acting on behalf of Beneficial Owners. Beneficial Owners will not receive certificates representing their ownership interests in the notes except in the event that use of the book-entry system for the notes is discontinued. As a result, the ability of a person having a beneficial interest in the notes to pledge such interest to persons or entities that do not participate in the DTC system, or to otherwise take actions with respect to such interest, may be affected by the lack of a physical certificate evidencing such interest. In addition, the laws of some states require that certain persons take physical delivery in definitive form of securities that they own and that security interests in negotiable instruments can only be perfected by delivery of certificates representing the instruments. Consequently, the ability to transfer notes evidenced by the global notes will be limited to such extent.

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

Conveyance of notices and other communications by DTC to Direct Participants, by Direct Participants to Indirect Participants, and by Direct Participants and Indirect Participants to Beneficial Owners will be governed by arrangements among them, subject to any statutory or regulatory requirements as may be in effect from time to time.

Beneficial Owners of notes may wish to take certain steps to augment the transmission to them of notices of significant events with respect to the notes, such as redemptions, tenders, defaults, and proposed amendments to the documents related to the notes. For example, Beneficial Owners of notes may wish to ascertain that the nominee holding the notes for their benefit has agreed to obtain and transmit notices to Beneficial Owners. In the alternative, Beneficial Owners may wish to provide their names and addresses to the registrar and request that copies of notices be provided directly to them.

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

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

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

Investors electing to hold their notes through DTC will follow the settlement practices applicable to U.S. corporate debt obligations. The securities custody accounts of investors will be credited with their holdings on the settlement date against payment insame-day funds within DTC effected in U.S. dollars.

Investors electing to hold their notes through Euroclear or Clearstream Banking accounts will follow the settlement procedures applicable to conventional eurobonds.

Secondary market sales of book-entry interests in the notes between DTC participants will occur in the ordinary way in accordance with DTC rules and will be settled using the procedures applicable to United States corporate debt obligations in DTC’s Settlement System. Secondary market sales of book-entry interests in the notes held through Euroclear or Clearstream Banking to purchasers of book-entry interests in the notes through Euroclear or Clearstream Banking will be conducted in accordance with the normal rules and operating procedures of Euroclear and Clearstream Banking and will be settled using the procedures applicable to conventional eurobonds.

DTC may discontinue providing its services as securities depositary with respect to the notes at any time by giving reasonable notice to us. Under such circumstances, in the event that a successor securities depositary is not obtained, note certificates are required to be printed and delivered. In addition, we may decide to discontinue use of the system of book-entry transfers through DTC (or a successor securities depositary). In that event, note certificates will be printed and delivered. See “Description of Debt Securities—Global Securities” in the accompanying prospectus.

We will not have any responsibility or obligation to participants in the DTC system or the persons for whom they act as nominees with respect to the accuracy of the records of DTC, its nominee or any Direct or Indirect Participant with respect to any ownership interest in the notes, or with respect to payments to or providing of notice for the Direct Participants, the Indirect Participants or the beneficial owners of the notes.

The information in this section concerning DTC, Euroclear, Clearstream Banking and their book-entry systems has been obtained from sources that we believe to be reliable. Neither we, the trustee nor the underwriters, dealers or agents are responsible for the accuracy or completeness of this information.

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U.S. FEDERAL INCOME TAX CONSIDERATIONS

The following discussion is a summary of U.S. federal income tax considerations generally applicable toNon-U.S. Holders (as defined below) with respect to an investment in the notes as of the date hereof. Unless otherwise noted, this summary deals only with notes that are held as capital assets within the meaning of the U.S. Internal Revenue Code of 1986, as amended (the “Code”) (generally property held for investment) by a holder that acquired the notes upon original issuance at their initial offering price.

This summary does not address all aspects of U.S. federal income taxation that may be relevant to a particular holder in light of that holder’s particular circumstances, or to certain types of holders subject to special treatment under U.S. federal income tax law (e.g., financial institutions, insurance companies, controlled foreign corporations, passive foreign investment companies, partnerships or other pass-through entities, expatriates or former long-term residents of the United States, persons subject to the alternative minimum tax, accrual basis taxpayers subject to special tax accounting rules pursuant to Section 451(b) of the Code, individual retirement accounts or othertax-deferred accounts, broker-dealers or other dealers in securities or currencies, traders in securities that elect to use amark-to-market method of accounting for their securities holdings, persons holding notes as a position in a “straddle,” or as part of a synthetic security or “hedge,” “conversion transaction,” “constructive sale” or other integrated investment, andtax-exempt organizations). Furthermore, this summary does not address other U.S. federal tax considerations (e.g., estate or gift tax or the Medicare tax on net investment income) or tax considerations arising under the tax laws of any state, locality ornon-U.S. jurisdiction.

This discussion is based on the Code, its legislative history, existing and proposed regulations, and published rulings and court decisions, all as in effect as of the date hereof, and all of which are subject to change, possibly with retroactive effect, which could alter the U.S. federal income tax considerations described below. No ruling from the Internal Revenue Service (“IRS”) has been or will be sought on any of the issues discussed herein, and there can be no assurance that the IRS or a court will concur with the conclusions reached below.

For purposes of this summary, a“Non-U.S. Holder” is a beneficial owner of notes (other than a partnership or other entity or arrangement classified as a partnership for U.S. federal income tax purposes) that is not a U.S. Holder. A “U.S. Holder” is a beneficial owner of notes that is for U.S. federal income tax purposes, (i) an individual citizen or resident of the United States, (ii) a corporation (or other entity that is treated as a corporation for U.S. federal income tax purposes) that is created or organized in or under the laws of the United States or any state or political subdivision thereof, (iii) an estate the income of which is includible in gross income for U.S. federal income tax purposes regardless of its source, or (iv) a trust if (a) it is subject to the primary supervision of a court within the United States and one or more United States persons are authorized to control all of its substantial decisions or (b) it has a valid election in effect under applicable United States Treasury regulations to be treated as a United States person.

If a partnership (or other entity or arrangement classified as a partnership for U.S. federal income tax purposes) holds notes, the tax treatment of a partner in such partnership generally will depend on the status of the partner and the activities of the partnership. Partnerships and other entities or arrangements that are classified as partnerships for U.S. federal income tax purposes and persons holding notes through any such entity should consult an independent tax advisor.

EACH PROSPECTIVE INVESTOR SHOULD CONSULT AN INDEPENDENT TAX ADVISOR AS TO THE U.S. FEDERAL, STATE, LOCAL,NON-U.S., AND ANY OTHER TAX CONSIDERATIONS OF AN INVESTMENT IN THE NOTES.

Interest

Subject to the discussion below under the heading “Additional Withholding Requirements under the Foreign Account Tax Compliance Act,” aNon-U.S. Holder generally will not be subject to U.S. federal withholding tax

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on interest received on the notes;provided that such interest is not effectively connected with such holder’s conduct of a trade or business in the United States and such holder (i) does not own, actually or constructively, 10% or more of the total combined voting power of all classes of our stock entitled to vote, (ii) is not a controlled foreign corporation directly or indirectly related to us within the meaning of Section 881(c)(3)(C) of the Code, (iii) satisfies certain certification requirements under penalty of perjury as to its status as aNon-U.S. Holder (generally through the provision of a properly completed and executed IRS FormW-8BEN,W-8BEN-E or other applicable IRS form) and (iv) is not subject to withholding required pursuant to FATCA (discussed below).

Except as described in the preceding paragraph, aNon-U.S. Holder generally will not be subject to U.S. federal income tax on interest received on the notes, unless such interest is effectively connected with the conduct by theNon-U.S. Holder of a trade or business in the United States (and, if an applicable treaty so requires, is attributable to the conduct of a trade or business through a permanent establishment or fixed base in the United States). ANon-U.S. Holder that is subject to U.S. federal income tax on interest under the rules described in the preceding sentence will not be subject to U.S. federal withholding tax on any such interest if the holder satisfies certain certification requirements under penalty of perjury (generally through the provision of a properly executed IRS FormW-8ECI). Interest that is effectively connected with the conduct by aNon-U.S. Holder of a trade or business in the United States (and, if an applicable treaty so requires, is attributable to the conduct of a trade or business through a permanent establishment or fixed base in the United States) will be subject to U.S. federal income tax on a net basis. In addition, if theNon-U.S. Holder is a foreign corporation, such holder may also be subject to a branch profits tax at a rate of 30% (or lower treaty rate, if applicable) on its effectively connected earnings and profits for the taxable year, subject to certain adjustments.

ANon-U.S. Holder that does not qualify for an exemption from U.S. federal withholding tax under the rules described above will generally be subject to withholding at a rate of 30% (or lower treaty rate, if applicable) on interest received on the notes.

Sale, Exchange, Retirement or Other Disposition of the Notes

Gain realized by aNon-U.S. Holder on the sale, exchange, retirement, or other disposition of the notes (other than amounts that represent accrued but unpaid interest, which will be subject to the rules regarding interest described above) generally will not be subject to U.S. federal withholding tax. Such gain also generally will not be subject to U.S. federal income tax, unless the gain is effectively connected with the conduct by theNon-U.S. Holder of a trade or business in the United States (and, if an applicable treaty so requires, is attributable to the conduct of a trade or business through a permanent establishment or fixed base in the United States) or, in the case of gain realized by an individualNon-U.S. Holder, theNon-U.S. Holder is present in the United States for 183 days or more in the taxable year of the disposition and certain other conditions are met.

Gain that is effectively connected with the conduct by aNon-U.S. Holder of a trade or business in the United States (and, if an applicable treaty so requires, is attributable to the conduct of a trade or business through a permanent establishment or fixed base in the United States) will be subject to U.S. federal income tax on a net basis. In addition, if theNon-U.S. Holder is a foreign corporation, such holder may also be subject to a branch profits tax at a rate of 30% (or lower treaty rate, if applicable) on its effectively connected earnings and profits for the taxable year, subject to certain adjustments.

Additional Withholding Requirements under the Foreign Account Tax Compliance Act

Sections 1471 through 1474 of the Code and the Treasury regulations and administrative guidance promulgated thereunder (commonly referred to as the “Foreign Account Tax Compliance Act” or “FATCA”) generally impose withholding at a rate of 30% in certain circumstances on interest payable on notes held by or through certain financial institutions (including investment funds), unless such institution (i) enters into, and complies with, an agreement with the IRS to report, on an annual basis, information with respect to interests in, and accounts maintained by, the institution that are owned by certain U.S. persons or by certainnon-U.S. entities that

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are wholly or partially owned by U.S. persons and to withhold on certain payments, or (ii) if required under an intergovernmental agreement between the United States and an applicable foreign country, reports such information to its local tax authority, which will exchange such information with the U.S. authorities. An intergovernmental agreement between the United States and an applicable foreign country may modify these requirements. Accordingly, the entity through which notes are held will affect the determination of whether such withholding is required. Similarly, interest payable on notes held by an investor that is anon-financialnon-U.S. entity that does not qualify under certain exemptions generally will be subject to withholding at a rate of 30%, unless such entity either (i) certifies that such entity does not have any “substantial United States owners” or (ii) provides certain information regarding the entity’s “substantial United States owners,” which the payor will generally be required to provide to the IRS. Each prospective investor is urged to consult its tax advisor regarding the possible implications of these rules on an investment in the notes.

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UNDERWRITING

Subject to the terms and conditions set forth in the underwriting agreement and related pricing agreement, each dated                , 2020, among us and the underwriters in the table below, for whom Barclays Capital Inc., Citigroup Global Markets Inc., Deutsche Bank Securities Inc. and J.P. Morgan Securities LLC are acting as representatives, we have agreed to sell to each of the underwriters, and each such underwriter has severally, and not jointly, agreed to purchase from us, the aggregate principal amount of the notes set forth opposite its name below:

The underwriters are committed to take and pay for all of the notes being offered, if any are taken.

The underwriters propose to offer the notes of each series directly to the public at the applicable public offering prices set forth on the cover page of this prospectus supplement and may offer the notes to certain dealers at that public offering prices less concessions not in excess of:

The underwriters may allow, and such dealers may reallow, concessions to certain other dealers not in excess of:

After the initial offering of the notes to the public, the representatives of the underwriters may change the public offering prices and concessions.

The following table shows the underwriting discounts that we are to pay to the underwriters in connection with this offering (expressed as a percentage of the principal amount of the notes).

We have agreed to indemnify the several underwriters against certain liabilities, including liabilities under the Securities Act, or to contribute to payments the underwriters may be required to make in respect of those liabilities.

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The underwriters are offering the notes, subject to prior sale, when, as and if issued to and accepted by them, subject to approval of legal matters by their counsel, including the validity of the notes, and other conditions contained in the underwriting agreement, such as the receipt by the underwriters of officer’s certificates and legal opinions. The underwriters reserve the right to withdraw, cancel or modify offers to the public and to reject orders in whole or in part.

In connection with the offering, the underwriters may purchase and sell notes in the open market. Purchases and sales in the open market may include short sales, purchases to cover short positions and stabilizing purchases.

Purchases to cover short positions and stabilizing purchases, as well as other purchases by the underwriters for their own accounts, may have the effect of preventing or retarding a decline in the market prices of the notes. They may also cause the prices of the notes to be higher than the price that would otherwise exist in the open market in theover-the-counter market or otherwise. If the underwriters commence any of these transactions, they may discontinue them at any time.

The underwriters and their respective affiliates are full service financial institutions engaged in various activities, which may include sales and trading, commercial and investment banking, advisory, investment management, investment research, principal investment, hedging, market making, brokerage and other financial andnon-financial activities and services. Certain of the underwriters and their affiliates have provided, and in the future may provide, certain investment and commercial banking and financial advisory services from time to time for us and our affiliates in the ordinary course of business for which they have received, and in the future would receive, customary fees and commissions. In addition, certain of the underwriters and their affiliates may act as agents or lenders under our credit facilities and hold positions in our outstanding securities. To the extent we use any net proceeds of this offering to repurchase existing debt and any of the underwriters or their affiliates own such existing debt that is purchased with the proceeds of this offering, they may receive proceeds from this offering through the repurchase of such existing debt.

In the ordinary course of their various business activities, the underwriters and their respective affiliates, officers, directors and employees may purchase, sell or hold a broad array of investments and actively traded securities, derivatives, loans, commodities, currencies, credit default swaps and other financial instruments for their own account and for the accounts of their customers, and such investment and trading activities may involve or relate to assets, securities and/or instruments of ours or our affiliates (directly, as collateral securing other obligations or otherwise) and/or persons and entities with relationships with us. If any of the underwriters or their affiliates has a lending relationship with us, certain of those underwriters or their affiliates routinely hedge, and certain other of those underwriters or their affiliates may hedge, their credit exposure to us consistent with their customary risk management policies. Typically, these underwriters and their affiliates would hedge such exposure by entering into transactions which consist of either the purchase of credit default swaps or the creation of short positions in our securities, including potentially the notes offered hereby. Any such credit default swaps or short positions could adversely affect future trading prices of the notes offered hereby. The underwriters and their respective affiliates may also communicate independent investment recommendations, market color or trading ideas and/or publish or express independent research views in respect of such assets, securities or instruments and may at any time hold, or recommend to clients that they should acquire, long and/or short positions in such assets, securities and instruments.

There are no public trading markets for the notes, and we do not intend to apply for listing of the notes on any national securities exchange or for quotation of the notes on any automated dealer quotation system. We have been advised by the underwriters that they presently intend to make a market in the notes of each series after the

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consummation of the offering, although they are under no obligation to do so and may discontinue any market-making activities at any time without any notice. Prior to the offering, there have been no active trading markets for the notes. No assurance can be given as to the existence or the liquidity of any trading markets for the notes or that active public trading markets for the notes will develop. If active trading markets for the notes do not develop, the market prices and liquidity of the notes may be adversely affected. If the notes of any series are traded, they may trade at a discount from their initial offering price, depending on prevailing interest rates, the market for similar securities, our performance and certain other factors.

We expect to deliver the notes against payment for the notes on or about the date specified in the last paragraph of the cover page of this prospectus supplement, which will be the seventh business day following the pricing of the notes. Since trades in the secondary market generally settle in two business days, purchasers who wish to trade notes prior to the date that is two business days prior to the delivery of the notes hereunder will be required, by virtue of the fact that the notes will settle in T+7, to specify alternative settlement arrangements at the time of any such trade to prevent a failed settlement. Purchasers of the notes who wish to trade the notes prior to the date that is two business days prior to the date of delivery hereunder should consult their advisors.

We estimate that our expenses in connection with this offering, excluding underwriting discounts and commissions, will be approximately $         . The underwriters have agreed to reimburse us for certain of our expenses in connection with the offering.

Notice to Prospective Investors in the European Economic Area and the United Kingdom

The notes are not intended to be offered, sold or otherwise made available to and should not be offered, sold or otherwise made available to any retail investor in the European Economic Area (“EEA”) or in the United Kingdom (“UK”). For these purposes, a retail investor means a person who is one (or more) of: (i) a retail client as defined in point (11) of Article 4(1) of Directive 2014/65/EU (as amended, “MiFID II”); or (ii) a customer within the meaning of Directive (EU) 2016/97 (the “Insurance Distribution Directive”), where that customer would not qualify as a professional client as defined in point (10) of Article 4 (1) of MiFID II; or (iii) not a qualified investor as defined in Regulation (EU) 2017/1129 (the “Prospectus Regulation”). Consequently no key information document required by Regulation (EU) No 1286/2014 (as amended, the “PRIIPs Regulation”) for offering or selling the notes or otherwise making them available to retail investors in the EEA or in the UK has been prepared and therefore offering or selling the notes or otherwise making them available to any retail investor in the EEA or in the UK may be unlawful under the PRIIPs Regulation. This prospectus supplement has been prepared on the basis that any offer of notes in any member state of the EEA or in the UK will be made pursuant to an exemption under the Prospectus Regulation from the requirement to publish a prospectus for offers of notes. This prospectus supplement is not a prospectus for the purposes of the Prospectus Regulation.

Notice to Prospective Investors in the United Kingdom

Each underwriter has represented and agreed that:

Notice to Prospective Investors in France

Neither this prospectus supplement nor any other offering material relating to the notes described in this prospectus supplement has been submitted to the clearance procedures of the Autorité des Marchés Financiers or

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of the competent authority of another member state of the European Economic Area and notified to the Autorité des Marchés Financiers. The notes have not been offered or sold and will not be offered or sold, directly or indirectly, to the public in France. Neither this prospectus supplement nor any other offering material relating to the notes has been or will be:

Such offers, sales and distributions will be made in France only:

The notes may be resold directly or indirectly, only in compliance with articlesL.411-1,L.411-2,L.412-1 andL.621-8 throughL.621-8-3 of the French Code monétaire et financier.

Notice to Prospective Investors in Switzerland

This prospectus supplement is not intended to constitute an offer or solicitation to purchase or invest in the notes. The notes may not be publicly offered, directly or indirectly, in Switzerland within the meaning of the Swiss Financial Services Act (“FinSA”) and no application has or will be made to admit the notes to trading on any trading venue (exchange or multilateral trading facility) in Switzerland. Neither this prospectus supplement nor any other offering or marketing material relating to the notes constitutes a prospectus pursuant to the FinSA, and neither this prospectus supplement nor any other offering or marketing material relating to the notes may be publicly distributed or otherwise made publicly available in Switzerland.

Notice to Prospective Investors in Hong Kong

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

Notice to Prospective Investors in Japan

The notes offered in this prospectus supplement have not been and will not be registered under the Financial Instruments and Exchange Law of Japan (Law No. 25 of 1948, as amended). The notes have not been offered or

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sold and will not be offered or sold, directly or indirectly, in Japan or to or for the account of any resident of Japan, except (i) pursuant to an exemption from the registration requirements of the Securities and Exchange Law and (ii) in compliance with any other applicable requirements of Japanese law.

Notice to Prospective Investors in Singapore

This prospectus supplement has not been registered as a prospectus with the Monetary Authority of Singapore (the “MAS”). Accordingly, this prospectus supplement and any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the notes may not be circulated or distributed, nor may the notes be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to persons in Singapore other than (i) to an institutional investor under Section 274 of the Securities and Futures Act, Chapter 289 of Singapore (the “SFA”), (ii) to a relevant person pursuant to Section 275(1), or any person pursuant to Section 275(1A), and in accordance with the conditions specified in Section 275 of the SFA or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA, in each case subject to compliance with conditions set forth in the SFA.

Where the notes are subscribed or purchased under Section 275 of the SFA by a relevant person which is:

shares, debentures and units of shares and debentures of that corporation or the beneficiaries’ rights and interest (howsoever described) in that trust shall not be transferred within six months after that corporation or that trust has acquired the notes pursuant to an offer made under Section 275 of the SFA except:

Singapore Securities and Futures Act Product Classification—Solely for the purposes of its obligations pursuant to sections 309B(1)(a) and 309B(1)(c) of the SFA, the Company has determined, and hereby notifies all relevant persons (as defined in Section 309A of the SFA) that the Notes are “prescribed capital markets products” (as defined in the Securities and Futures (Capital Markets Products) Regulations 2018) and Excluded Investment Products (as defined in MAS Notice SFA04-N12: Notice on the Sale of Investment Products and MAS NoticeFAA-N16: Notice on Recommendations on Investment Products).

Notice to Prospective Investors in Canada

The notes may be sold in Canada only to purchasers purchasing, or deemed to be purchasing, as principal that are accredited investors, as defined in National Instrument45-106 Prospectus Exemptions or subsection 73.3(1) of the Securities Act (Ontario), and are permitted clients, as defined in National Instrument31-103 Registration Requirements, Exemptions and Ongoing Registrant Obligations. Any resale of the notes must be made in accordance with an exemption from, or in a transaction not subject to, the prospectus requirements of applicable securities laws.

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

Pursuant to section 3A.3 of National Instrument33-105 Underwriting Conflicts (NI33-105), the underwriters are not required to comply with the disclosure requirements of NI33-105 regarding underwriter conflicts of interest in connection with this offering.

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LEGAL MATTERS

Margaret M. Madden, our Senior Vice President and Corporate Secretary, Chief Governance Counsel, will pass upon the validity of the notes. Ms. Madden beneficially owns, or has the right to acquire under our employee benefit plans, an aggregate of less than 1% of the outstanding shares of our common stock. Skadden, Arps, Slate, Meagher & Flom LLP, New York, New York, is also acting as legal counsel to us in connection with this offering. Simpson Thacher & Bartlett LLP, New York, New York, will pass upon various legal matters for the underwriters relating to the offering.

EXPERTS

The consolidated financial statements of Pfizer Inc. and Subsidiary Companies as of December 31, 2019 and 2018, and for each of the years in the three-year period ended December 31, 2019, and management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2019, have been incorporated by reference herein and in the registration statement in reliance upon the reports of KPMG LLP, independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing.

With respect to the unaudited interim financial information for the periods ended March 29, 2020 and March 31, 2019, incorporated by reference herein, the independent registered public accounting firm has reported that they applied limited procedures in accordance with professional standards for a review of such information. However, their separate report included in the Company’s quarterly report on Form10-Q for the quarter ended March 29, 2020, and incorporated by reference herein, states that they did not audit and they do not express an opinion on that interim financial information. Accordingly, the degree of reliance on their report on such information should be restricted in light of the limited nature of the review procedures applied. The accountants are not subject to the liability provisions of Section 11 of the Securities Act for their report on the unaudited interim financial information because the report is not a “report” or a “part” of the registration statement prepared or certified by the accountants within the meaning of Sections 7 and 11 of the Securities Act.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and special reports, proxy statements and other information with the SEC. Our SEC filings are available at the Internet website maintained by the SEC at http://www.sec.gov. The filings are also available on our website at http://www.pfizer.com.

THIS PROSPECTUS SUPPLEMENT INCORPORATES DOCUMENTS BY REFERENCE WHICH ARE NOT PRESENTED IN OR DELIVERED WITH THIS PROSPECTUS SUPPLEMENT. YOU SHOULD RELY ONLY ON THE INFORMATION CONTAINED IN THIS PROSPECTUS SUPPLEMENT AND IN THE DOCUMENTS THAT WE HAVE INCORPORATED BY REFERENCE IN THIS PROSPECTUS SUPPLEMENT. WE HAVE NOT, AND THE UNDERWRITERS HAVE NOT, AUTHORIZED ANYONE TO PROVIDE YOU WITH INFORMATION THAT IS DIFFERENT FROM OR IN ADDITION TO THE INFORMATION CONTAINED IN THIS PROSPECTUS SUPPLEMENT, THE ACCOMPANYING PROSPECTUS AND IN THE DOCUMENTS THAT WE HAVE INCORPORATED BY REFERENCE IN THIS PROSPECTUS SUPPLEMENT AND THE ACCOMPANYING PROSPECTUS AND ANY FREE WRITING PROSPECTUS THAT WE MAY PROVIDE YOU IN CONNECTION WITH THIS OFFERING. 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 incorporate information into this prospectus supplement by reference, which means that we disclose important information to you by referring you to another document filed separately with the SEC. The

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information incorporated by reference is deemed to be part of this prospectus supplement, except to the extent superseded by information contained in this prospectus supplement, the accompanying prospectus or by information contained in documents filed with the SEC after the date of this prospectus supplement. This prospectus supplement incorporates by reference the documents set forth below that have been previously filed with the SEC;provided, however, that we are not incorporating any documents or information deemed to have been furnished rather than filed in accordance with SEC rules. These documents contain important information about us and our financial condition.

We also incorporate by reference any future filings made with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act between the date of this prospectus supplement and the date all of the securities offered by this prospectus supplement are sold or the offering is otherwise terminated, with the exception of any information furnished under Item 2.02 and Item 7.01 of Form8-K, which is not deemed filed and which is not incorporated by reference in this prospectus supplement. Any such filings shall be deemed to be incorporated by reference and to be a part of this prospectus supplement from the respective dates of filing of those documents.

We will provide without charge upon written or oral request to each person, including any beneficial owner, to whom a prospectus is delivered, a copy of any and all of the documents which are incorporated by reference in this prospectus supplement but not delivered with this prospectus supplement (other than exhibits unless such exhibits are specifically incorporated by reference in such documents). You may request a copy of these documents by writing or telephoning us at:

Senior Vice President and Corporate Secretary

Pfizer Inc.

235 East 42nd Street

New York, NY 10017

(212)733-2323

The information contained on our website, our Facebook, YouTube and LinkedIn pages or our Twitter accounts does not, and shall not be deemed to, constitute a part of this prospectus supplement.

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PROSPECTUS

PFIZER INC.

DEBT SECURITIES

COMMON STOCK

PREFERRED STOCK

WARRANTS

DEPOSITARY SHARES

PURCHASE CONTRACTS

PURCHASE UNITS

GUARANTEES

We may from time to time offer to sell debt securities, common stock, preferred stock, warrants, depositary shares, purchase contracts, purchase units or guarantees. Each time we sell securities pursuant to this prospectus, we will provide a supplement to this prospectus that contains specific information about the offering and the specific terms of the securities offered. The prospectus supplement may also add to, update or change information contained in this prospectus. In addition, we may supplement, update or change any of the information contained in this prospectus by incorporating information by reference in this prospectus.

In addition, selling securityholders to be named in a prospectus supplement may offer our securities from time to time. To the extent that any selling securityholder resells any securities, the selling securityholder may be required to provide you with this prospectus and a prospectus supplement identifying and containing specific information about the selling securityholder and the terms of the securities being offered.

You should read this prospectus, the supplements to this prospectus and any incorporated documents carefully before you invest in any of our securities. This prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any state or other jurisdiction where the offer or sale is not permitted.

We may offer and sell securities to or through one or more underwriters, dealers and agents, or directly to purchasers. The names and compensation of any underwriters or agents involved in the sale of securities will be described in a supplement to this prospectus.

Our common stock is listed on the New York Stock Exchange under the symbol “PFE.” If we decide to seek a listing of any securities offered by this prospectus, the applicable prospectus supplement will disclose the exchange or market on which such securities will be listed, if any, or where we have made an application for listing, if any.

Investing in our securities involves risk. You should carefully consider the risk factors incorporated in this prospectus by reference and described under the heading “Risk Factors” beginning on page 4.

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED IF THIS PROSPECTUS IS TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

The date of this prospectus is February 26, 2018.

TABLE OF CONTENTS

No person is authorized to give any information or to make any representations other than those contained or incorporated by reference in this prospectus, any accompanying prospectus supplement or any free writing prospectus we may provide you in connection with an offering. We take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. This prospectus and any accompanying prospectus supplement are not an offer to sell or the solicitation of an offer to buy any securities in any jurisdiction where it is unlawful. Neither the delivery of this prospectus or any accompanying prospectus supplement, nor any sale of securities made under these documents, will, under any circumstances, create any implication that there has been no change in our affairs since the date of this prospectus, any accompanying prospectus supplement or any free writing prospectus we may provide you in connection with an offering or that the information contained or incorporated by reference is correct as of any time subsequent to the date of such information. You should assume that the information in this prospectus or any accompanying prospectus supplement, as well as the information incorporated by reference in this prospectus or any accompanying prospectus supplement, is accurate only as of the date of the documents containing the information, unless the information specifically indicates that another date applies. Our business, financial condition, results of operations and prospects may have changed since those dates.

ABOUT THIS PROSPECTUS

This prospectus is part of an “automatic shelf” registration statement that we filed with the Securities and Exchange Commission (the SEC), as a “well-known seasoned issuer” as defined in Rule 405 under the Securities Act of 1933, as amended (the Securities Act) using a “shelf” registration process. We may sell any combination of the securities described in this prospectus from time to time in one or more offerings, and selling securityholders may offer such securities owned by them from time to time. You should carefully read this prospectus and any accompanying prospectus supplement together with the additional information described under the heading “Where You Can Find More Information.”

This prospectus provides you with a general description of the securities that may be offered by us and/or selling securityholders. Each time we sell securities pursuant to this prospectus, we will provide a prospectus supplement that contains specific information about the terms of that offering, including the specific amounts, prices and terms of the securities offered. If this prospectus is inconsistent with the prospectus supplement, you should rely upon the prospectus supplement. In addition, the prospectus supplement may also add, update or change the information contained in this prospectus.

If you are in a jurisdiction where offers to sell, or solicitations of offers to purchase, the securities offered by this document are unlawful, or if you are a person to whom it is unlawful to direct these types of activities, then the offer presented in this document does not extend to you.

Wherever references are made in this prospectus to information that will be included in a prospectus supplement, to the extent permitted by applicable law, rules or regulations, we may instead include such information or add, update or change the information contained in this prospectus by means of a post-effective amendment to the registration statement of which this prospectus is a part, through filings we make with the SEC that are incorporated by reference in this prospectus or by any other method as may then be permitted under applicable law, rules or regulations. For purposes of this prospectus, any reference to a prospectus supplement may also refer to a free writing prospectus unless the context requires otherwise.

References in this prospectus to “Pfizer,” the “Company,” “we,” “us” and “our” are to Pfizer Inc. and its consolidated subsidiaries, unless otherwise stated or the context so requires.

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and any accompanying prospectus supplement, as well as the information incorporated by reference in this prospectus or any accompanying prospectus supplement, may include forward-looking statements made within the meaning of Section 27A of the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended (the Exchange Act). Such forward-looking statements involve substantial risks and uncertainties. We have tried, wherever possible, to identify such statements by using words such as “will,” “may,” “could,” “likely,” “ongoing,” “anticipate,” “estimate,” “expect,” “project,” “intend,” “plan,” “believe,” “assume,” “target,” “forecast,” “guidance,” “goal,” “objective,” “aim,” and other words and terms of similar meaning, or by using future dates in connection with any discussion of, among other things, our anticipated operating and financial performance, business plans and prospects,in-line products and product candidates, including anticipated regulatory submissions, data read-outs, approvals, performance, timing of exclusivity and potential benefits of Pfizer’s products and product candidates, strategic reviews, capital allocation, business-development plans, manufacturing and product supply and plans relating to share repurchases and dividends. In particular, these include statements relating to future actions, business plans and prospects, our acquisitions and other business development activities, the disposition of the Hospira Infusion Systems net assets, prospective products or product approvals, future performance or results of current and anticipated products, sales efforts, expenses, interest rates, foreign exchange rates, the outcome of contingencies, such as legal proceedings, plans relating to share repurchases and dividends, government regulation and financial results.

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A list and description of risks, uncertainties and other matters can be found in our Annual Report onForm 10-K for the year ended December 31, 2017, including in the sections thereof captioned “Forward-Looking Information and Factors That May Affect Future Results” and “Item 1A. Risk Factors,” in our subsequent Quarterly Reports onForm 10-Q and Current Reports onForm 8-K, and in this prospectus and any accompanying prospectus supplement, in each case including in the section thereof captioned “Risk Factors.” You should understand that it is not possible to predict or identify all such factors. Consequently, you should not consider any such list to be a complete set of all potential risks or uncertainties.

We cannot guarantee that any forward-looking statement will be realized, although we believe we have been prudent in our plans and assumptions. Achievement of anticipated results is subject to substantial risks, uncertainties and inaccurate assumptions. Should known or unknown risks or uncertainties materialize, or should underlying assumptions prove inaccurate, actual results could vary materially from past results and those anticipated, estimated or projected. You should bear this in mind as you consider forward-looking statements, and you are cautioned not to put undue reliance on forward-looking statements.

We undertake no obligation to publicly update forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law or by the rules and regulations of the SEC. You are advised, however, to consult any further disclosures we make on related subjects in ourForm 10-K,10-Q and8-K reports and our other filings with the SEC.

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THE COMPANY

Pfizer Inc. is a research-based, global biopharmaceutical company. We apply science and our global resources to bring therapies to people that extend and significantly improve their lives through the discovery, development and manufacture of healthcare products. Our global portfolio includes medicines and vaccines, as well as many of the world’s best-known consumer healthcare products. We work across developed and emerging markets to advance wellness, prevention, treatments and cures that challenge the most feared diseases of our time. We collaborate with healthcare providers, governments and local communities to support and expand access to reliable, affordable healthcare around the world. Our revenues are derived from the sale of our products, and, to a much lesser extent, from alliance agreements, under which weco-promote products discovered or developed by other companies or us. The majority of our revenues come from the manufacture and sale of biopharmaceutical products.

The Company was incorporated under the laws of the State of Delaware on June 2, 1942.

Our principal executive offices are located at 235 East 42nd Street, New York, NY 10017, and our telephone number is(212) 733-2323.

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RISK FACTORS

You should consider carefully the information under the headings “Risk Factors” in our Annual Report onForm 10-K for the year ended December 31, 2017, in any applicable prospectus supplement and any risk factors set forth in our other filings with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, including our Quarterly Reports onForm 10-Q and our Current Reports onForm 8-K, before making an investment decision. Each of the risks described in these documents could materially and adversely affect our business, financial condition, results of operations and prospects, and could result in a partial or complete loss of your investment. See “Where You Can Find More Information.”

RATIO OF EARNINGS TO FIXED CHARGES

Our consolidated ratio of “earnings” to “fixed charges” for each of the years ended December 31, 2013 through 2017 is set forth below.

For purposes of computing the ratio of earnings to fixed charges, “earnings” consists of income from continuing operations before provision for taxes on income and before income or loss from equity-method investments, plus fixed charges, distributed income of equity-method investments and amortization of capitalized interest, and less capitalized interest. “Fixed charges” consists of interest expense (which includes amortization of debt premium, discount and other debt costs), preferred stock dividends,one-third of rental expense, which we believe to be a conservative estimate of an interest factor in our leases, which are not material, and capitalized interest. The ratio was calculated by dividing the sum of the earnings (as defined above) by the sum of the fixed charges (as defined above).

USE OF PROCEEDS

Unless the applicable prospectus supplement indicates otherwise, we intend to use net proceeds from the sale of the securities for general corporate purposes, including working capital, capital expenditures, payment of dividends, share repurchases, acquisitions and the refinancing of existing debt. We may use funds that are not immediately needed for these purposes to temporarily invest in short-term marketable securities.

Unless set forth in an accompanying prospectus supplement, we will not receive any proceeds in the event that securities are sold by a selling security holder.

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DESCRIPTION OF DEBT SECURITIES

We may offer debt securities in one or more series, which may be senior debt securities or subordinated debt securities and which may be convertible into another security.

The following description briefly sets forth certain general terms and provisions of the debt securities. The particular terms of the debt securities offered by any prospectus supplement and the extent, if any, to which the following general terms and provisions may apply to the debt securities, will be described in an accompanying prospectus supplement. Unless otherwise specified in an accompanying prospectus supplement, our debt securities will be issued in one or more series under an indenture to be entered into between us and The Bank of New York Mellon, as trustee, or such other trustee named therein. A form of the indenture is attached as an exhibit to the registration statement of which this prospectus forms a part. The terms of the debt securities will include those set forth in the indenture and those made a part of the indenture by the Trust Indenture Act of 1939 (TIA). You should read the summary below, any accompanying prospectus supplement and the provisions of the indenture in their entirety before investing in our debt securities.

The aggregate principal amount of debt securities that may be issued under the indenture is unlimited. The prospectus supplement relating to any series of debt securities that we may offer will contain the specific terms of the debt securities. These terms may include, among others, the following:

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General

We may issue the debt securities in one or more series with the same or various maturities, at par or a premium or with original issue discount. Unless we inform you otherwise in a prospectus supplement, we may issue additional debt securities of a particular series without the consent of the holders of the debt securities of such series or any other series outstanding at the time of issuance. Any such additional debt securities, together with all other outstanding debt securities of that series, will constitute a single series of securities under the indenture.

We will describe in an accompanying prospectus supplement any other special considerations for any debt securities we sell that are denominated in a currency or currency unit other than U.S. dollars. In addition, debt securities may be issued where the amount of principal and/or interest payable is determined by reference to one or more currency exchange rates, commodity prices, equity indices or other factors. Holders of such securities may receive a principal amount or a payment of interest that is greater than or less than the amount of principal or interest otherwise payable on such dates, depending upon the value of the applicable currencies, commodities, equity indices or other factors. Information as to the methods for determining the amount of principal or interest, if any, payable on any date, and the currencies, commodities, equity indices or other factors to which the amount payable on such date is linked will be described in an accompanying prospectus supplement.

United States federal income tax consequences and special considerations, if any, applicable to any such series will be described in an accompanying prospectus supplement.

Unless otherwise specified in an accompanying prospectus supplement, the debt securities will be issued in fully registered form without coupons and in denominations of $2,000 and any integral multiple of $1,000 in excess thereof. Subject to the limitations provided in the indenture and in an accompanying prospectus supplement, debt securities that are issued in registered form may be transferred or exchanged at the designated corporate trust office of the trustee, without the payment of any service charge, other than any tax or other governmental charge payable in connection therewith.

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Consolidation, Merger or Sale

We have agreed not to consolidate with or merge into any other person or convey or transfer our properties and assets as an entirety or substantially as an entirety to any other person, unless:

The successor will assume all our obligations for payment under the securities and our obligations under the indenture as if it were an original party to the indenture. After assuming such obligations, the successor will have all our rights and powers under the indenture.

Modification of Indenture

Under the indenture, we and the applicable trustee may supplement the indenture for certain purposes which would not adversely affect the interests of the holders of debt securities of a series in any material respect without the consent of those holders. Under the indenture, the rights of the holders may be modified through a supplemental indenture if the holders of at least a majority in aggregate principal amount of the outstanding debt securities of all series affected by the modification (voting as one class) consent to it. No modification of the maturity date, principal or interest payment terms or premium payable on redemption, no modification of the currency for payment, no impairment of the right to sue for the enforcement of payment at the maturity of the debt security, no modification of any conversion rights, no modification reducing the percentage required for any such supplemental indenture or the percentage required for the waiver of compliance with certain provisions of the indenture or certain defaults, and no modification of the foregoing provisions or any other provisions relating to the waiver of past defaults or the waiver of certain covenants, is effective against any holder without its consent.

Events of Default

Each of the following will constitute an event of default under the indenture with respect to debt securities of any series:

The supplemental indenture or the form of security for a particular series of debt securities may include additional events of default or changes to the events of default described above. The events of default applicable to a particular series of debt securities will be discussed in the prospectus supplement relating to such series. A default under our other indebtedness will not be a default under the indenture for the debt securities covered by this prospectus, and a default under one series of debt securities will not necessarily be a default under another

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series. The trustee may withhold notice to the holders of debt securities of any default (except for defaults that involve our failure to pay principal or interest) if it considers such withholding of notice to be in the best interests of the holders.

If an event of default with respect to outstanding debt securities of any series occurs and is continuing, then the trustee or the holders of at least 33% in principal amount of outstanding debt securities of that series may declare, in a written notice, the principal amount (or, if any of the securities of that series are original issue discount securities, such portion of the principal amount of such securities as specified in the terms thereof) plus accrued and unpaid interest on all debt securities of that series to be immediately due and payable. At any time after a declaration of acceleration with respect to debt securities of any series has been made and before a judgment or decree for the payment of money due has been obtained by the trustee, the event of default giving rise to such declaration of acceleration shall, without further act, be deemed to have been rescinded and annulled, if:

We refer you to the prospectus supplement relating to any series of debt securities that are discount securities for the particular provisions relating to acceleration of a portion of the principal amount of the discount securities upon the occurrence of an event of default.

If a default in the performance or breach of the indenture shall have occurred and be continuing, the holders of not less than a majority in principal amount of the outstanding securities of all series affected thereby, by notice to the trustee, may waive any past event of default or its consequences under the indenture. However, an event of default cannot be waived without the consent of the holders of each outstanding security of the series affected with respect to any series of securities in the following two circumstances:

The trustee is not obligated to exercise any of its rights or powers under the indenture at the request, order or direction of any holders, unless the holders offer the trustee security or indemnity reasonably satisfactory to the trustee. Holders of a majority in principal amount outstanding of any series of debt securities may, subject to certain limitations, direct the time, method and place of conducting any proceeding or any remedy available to the trustee, or exercising any power conferred upon the trustee, for such applicable series of debt securities.

We are required to deliver an annual officer’s certificate to the trustee stating whether we are in default in the performance and observance of any of the terms, provisions and conditions of the indenture, and, if we are in default, specifying all such defaults and the nature and status thereof.

Payment and Transfer and Exchange

We will pay principal, interest and any premium on fully registered securities at the place or places designated by us for such purposes. We will make payment to the persons in whose names the debt securities are registered on the close of business on the record date for such interest. Any other payments will be made as set forth in the applicable prospectus supplement.

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Holders may transfer or exchange fully registered securities at any office or agency maintained by us for such purposes, without the payment of any service charge except for any tax or governmental charge we are required to pay in connection with a transfer or exchange.

Upon surrender for registration of transfer of any security of any series in accordance with the terms of the indenture, we shall execute, and the trustee shall authenticate and deliver or make available for delivery, in the name of the designated transferee or transferees, one or more new securities of the same series, of any authorized denominations and of like tenor and aggregate principal amount.

If the securities of any series are to be redeemed, we are not required to:

Global Securities

Unless we inform you otherwise in an accompanying prospectus supplement, the debt securities of a series may be issued in whole or in part in the form of one or more global securities that will be deposited with, or on behalf of, a depositary identified in an accompanying prospectus supplement. Unless and until a global security is exchanged in whole or in part for the individual debt securities, a global security may not be transferred except as a whole by the depositary for such global security to a nominee of such depositary or by a nominee of such depositary to such depositary or another nominee of such depositary or by such depositary or any such nominee to a successor of such depositary or a nominee of such successor.

Defeasance

When we use the term defeasance, we mean discharge from some or all of our obligations under the indenture. Subject to certain additional conditions, if we irrevocably deposit with the trustee sufficient cash or government securities to pay the principal, interest, any premium and any other sums due to the stated maturity date or a redemption date of the debt securities of a particular series, then at our option:

To exercise our defeasance option, we must deliver to the trustee an officer’s certificate and an opinion of counsel, each stating that all conditions precedent related to the defeasance have been complied with.

Concerning the Trustee

The trustee, The Bank of New York Mellon, has provided banking and investment services to us in the past and may do so in the future as a part of its regular business.

Governing Law

The indenture and the debt securities shall be construed in accordance with and governed by the laws of the State of New York.

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DESCRIPTION OF CAPITAL STOCK

General

The following description of certain terms of our capital stock does not purport to be complete and is subject to, and qualified in its entirety by reference to, our restated certificate of incorporation, as amended (the Certificate of Incorporation), ourby-laws, as amended (theBy-Laws), and the applicable provisions of the Delaware General Corporation Law (the DGCL). For more information on how you can obtain the Certificate of Incorporation and theBy-Laws, see “Where You Can Find More Information.”

Common Stock

Under the Certificate of Incorporation, we are authorized to issue up to 12 billion shares of common stock, par value $0.05 per share. The common stock is not redeemable, does not have any conversion rights and is not subject to call. Holders of shares of common stock have no preemptive rights to maintain their percentage of ownership in future offerings or sales of our stock. Holders of shares of common stock have one vote per share in all elections of Directors and on all other matters submitted to vote of our stockholders. The holders of common stock are entitled to receive dividends, if any, as and when may be declared from time to time by our Board of Directors out of funds legally available therefor. Upon liquidation, dissolution or winding up of our affairs, the holders of common stock will be entitled to participate equally and ratably, in proportion to the number of shares held, in our net assets available for distribution to holders of common stock. The shares of common stock currently outstanding are fully paid and nonassessable. As of February 20, 2018, there were 5,952,864,751 shares of common stock issued and outstanding.

The prospectus supplement relating to any common stock being offered will include specific terms relating to the offering.

Preferred Stock

Under the Certificate of Incorporation, we are authorized to issue up to 27 million shares of preferred stock, without par value, of which 7,500 shares of preferred stock have been designated Series A convertible perpetual preferred stock. The preferred stock may be issued in one or more series, and the Board of Directors of Pfizer is expressly authorized (i) to fix the descriptions, powers, preferences, rights, qualifications, limitations, and restrictions with respect to any series of preferred stock and (ii) to specify the number of shares of any series of preferred stock. As of February 20, 2018, there were 517.05 shares of preferred stock issued and outstanding.

The prospectus supplement relating to any preferred stock being offered will include specific terms relating to the offering.

Series A Convertible Perpetual Preferred Stock. Our Series A convertible perpetual preferred stock is held by an Employee Stock Ownership Plan (Preferred ESOP) Trust and provides dividends in an amount not to exceed 6.25% of the stated value, which are paid quarterly. The stated value is $40,300 per share, and the Series A convertible perpetual preferred stock ranks senior to our common stock and junior to all other preferred stock, unless designated as ranking senior or on a parity with the new preferred stock as to dividends and liquidation rights. Each share is convertible, at the holder’s option, at a conversion rate initially equivalent to 2,574.8685 shares of our common stock for each preferred share converted, subject to adjustment. Each share of Series A convertible perpetual preferred stock is entitled to a number of votes equal to the number of shares of common stock into which such convertible perpetual preferred stock could be converted on the record date for determining the stockholders entitled to vote in any matter submitted to the stockholders to vote. The holders of Series A convertible perpetual preferred stock are entitled to vote on all matters submitted to a vote of the stockholders, voting together with the holders of common stock as one class. The conversion option is indexed to

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our common stock and requires share settlement, and, therefore, is reported at the fair value at the date of issuance. We may redeem the Series A convertible perpetual preferred stock at any time or upon termination of the Preferred ESOP, at our option, in cash, in shares of common stock, or a combination of both at a price of $40,300 per share, plus any accrued and unpaid dividends to the redemption date. We will also redeem the Series A convertible perpetual preferred stock in cash, or at our election, in shares of common stock, or a combination of any shares of common stock to be valued at their fair market value, at a price of $40,300 per share, upon certification of the holder to us of certain events.

Anti-takeover Effects of the Certificate of Incorporation,By-laws and Delaware Law

Certificate of Incorporation andBy-laws. Various provisions contained in the Certificate of Incorporation and theBy-laws could delay or discourage some transactions involving an actual or potential change in control of us or a change in our management and may limit the ability of our stockholders to remove current management or approve transactions that our stockholders may deem to be in their best interests. Among other things, these provisions:

Delaware Law. We are a Delaware corporation and consequently are also subject to certain anti-takeover provisions of the DGCL. Subject to certain exceptions, Section 203 of the DGCL prevents a publicly held Delaware corporation from engaging in a “business combination” with any “interested stockholder” for three years following the date that the person became an interested stockholder, unless (a) the interested stockholder attained such status with the approval of the corporation’s board of directors, (b) upon consummation of the transaction that resulted in the stockholder becoming an interested stockholder, the interested stockholder owned at least 85% of the voting stock of the corporation outstanding at the time the transaction commenced, exclusive of shares owned by directors who are also officers and by certain employee stock plans or (c) at or subsequent to such time, the business combination is approved by the board of directors and authorized by the affirmative vote at a stockholders’ meeting, and not by written consent, of at least 66 2/3% of the outstanding voting stock which is not owned by the interested stockholder. A “business combination” includes, among other things, a merger or consolidation involving the corporation and the “interested stockholder” and the sale of more than 10% of the corporation’s assets. In general, an “interested stockholder” is any entity or person beneficially owning 15% or more of the corporation’s outstanding voting stock, and any entity or person affiliated with or controlling or controlled by such entity or person. Section 203 makes it more difficult for an interested stockholder to effect various business combinations with a corporation for a three-year period. This statute could prohibit or delay mergers or other takeover or change in control attempts not approved in advance by our Board of Directors, and, as a result, could discourage attempts to acquire us, which could depress the market price of our common stock.

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DESCRIPTION OF OTHER SECURITIES

We will set forth, in the applicable prospectus supplement, a description of any warrants, depositary shares, purchase contracts, purchase units or guarantees that may be offered pursuant to this prospectus.

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SELLING SECURITYHOLDERS

Selling securityholders are persons or entities that, directly or indirectly, have acquired or will from time to time acquire from us, our securities in various private transactions. Such selling securityholders may be parties to registration rights agreements with us, or we otherwise may have agreed or will agree to register their securities for resale. The initial purchasers of our securities, as well as their transferees, pledgees, donees or successors, all of whom we refer to as “selling securityholders,” may from time to time offer and sell the securities pursuant to this prospectus and any applicable prospectus supplement.

The applicable prospectus supplement will set forth the name of each selling securityholder and the number of and type of securities beneficially owned by such selling securityholder that are covered by such prospectus supplement. The applicable prospectus supplement also will disclose whether any of the selling securityholders have held any position or office with, have been employed by or otherwise have had a material relationship with us during the three years prior to the date of the prospectus supplement.

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PLAN OF DISTRIBUTION

We and any selling securityholder may sell the securities offered by this prospectus from time to time in one or more transactions, including without limitation:

In addition, we, or any selling securityholder, may enter into derivative or hedging transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. In connection with such a transaction, the third parties may sell securities covered by and pursuant to this prospectus and an applicable prospectus supplement. If so, the third party may use securities borrowed from us or others to settle such sales and may use securities received from us to close out any related short positions. We may also loan or pledge securities covered by this prospectus and an applicable prospectus supplement to third parties, who may sell the loaned securities or, in an event of default in the case of a pledge, sell the pledged securities pursuant to this prospectus and the applicable prospectus supplement.

We and any selling securityholder may sell the securities offered by this prospectus at:

We will identify the specific plan of distribution, including any underwriters, dealers, agents or direct purchasers, and their compensation in a prospectus supplement.

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LEGAL MATTERS

Margaret M. Madden, our Senior Vice President and Corporate Secretary, Chief Governance Counsel, will pass upon the validity of the securities for us. Ms. Madden beneficially owns, or has the right to acquire under our employee benefit plans, an aggregate of less than 1% of the outstanding shares of our common stock.

EXPERTS

The consolidated balance sheets of Pfizer Inc. and Subsidiary Companies as of December 31, 2017 and 2016 and the related consolidated statements of income, comprehensive income, equity, and cash flows for each of the years in the three-year period ended December 31, 2017, and management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2017, have been incorporated by reference herein in reliance upon the reports of KPMG LLP, independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in auditing and accounting.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and special reports, proxy statements and other information with the SEC. You may read and copy any reports, statements or other information on file at the SEC’s public reference room at 100 F Street, N.E., Washington, D.C., 20549. Please call the SEC at1-800-SEC-0330 for further information on the public reference room. The SEC filings are also available to the public from commercial document retrieval services. These filings are also available at the Internet website maintained by the SEC at http://www.sec.gov. The filings are also available on our website at http://www.pfizer.com.

THIS PROSPECTUS INCORPORATES DOCUMENTS BY REFERENCE WHICH ARE NOT PRESENTED IN OR DELIVERED WITH THIS PROSPECTUS. YOU SHOULD RELY ONLY ON THE INFORMATION CONTAINED IN THIS PROSPECTUS AND IN THE DOCUMENTS THAT WE HAVE INCORPORATED BY REFERENCE IN THIS PROSPECTUS. WE HAVE NOT AUTHORIZED ANYONE TO PROVIDE YOU WITH INFORMATION THAT IS DIFFERENT FROM OR IN ADDITION TO THE INFORMATION CONTAINED IN THIS DOCUMENT AND INCORPORATED BY REFERENCE IN THIS PROSPECTUS.

We incorporate information into this prospectus by reference, which means that we disclose important information to you by referring you to another document filed separately with the SEC. The information incorporated by reference is deemed to be part of this prospectus, except to the extent superseded by information contained in this prospectus or by information contained in documents filed with the SEC after the date of this prospectus. This prospectus incorporates by reference the documents set forth below that have been previously filed with the SEC. These documents contain important information about us and our financial condition.

We also incorporate by reference any future filings made with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act between the date of this prospectus and the date all of the securities offered by this prospectus are sold or the offering is otherwise terminated, with the exception of any information furnished under Item 2.02 and Item 7.01 ofForm 8-K, which is not deemed filed and which is not incorporated by reference in

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this prospectus. Any such filings shall be deemed to be incorporated by reference and to be a part of this prospectus from the respective dates of filing of those documents.

We will provide without charge upon written or oral request to each person, including any beneficial owner, to whom a prospectus is delivered, a copy of any and all of the documents which are incorporated by reference in this prospectus but not delivered with this prospectus (other than exhibits unless such exhibits are specifically incorporated by reference in such documents). You may request a copy of these documents by writing or telephoning us at:

Senior Vice President and Corporate Secretary

Pfizer Inc.

235 East 42nd Street

New York, NY 10017

(212)733-2323

The information contained in our website does not constitute a part of this prospectus.

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