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TABLE OF CONTENTS Prospectus Supplement
TABLE OF CONTENTS

Table of Contents

Filed Pursuant to Rule 424(b)(5)
Registration Statement No. 333-205812

Prospectus Supplement
(To Prospectus dated August 18, 2015)

LOGO

EQT Midstream Partners, LP

Common Units Representing Limited Partner Interests
Having an Aggregate Offering Price of up to $750,000,000



         We have entered into an equity distribution agreement with Deutsche Bank Securities Inc., Barclays Capital Inc., BNP Paribas Securities Corp., Merrill Lynch, Pierce, Fenner & Smith Incorporated, Citigroup Global Markets Inc., Credit Suisse Securities (USA) LLC, Goldman, Sachs & Co., J.P. Morgan Securities LLC, Mitsubishi UFJ Securities (USA), Inc., RBC Capital Markets, LLC, Scotia Capital (USA) Inc., SunTrust Robinson Humphrey, Inc., USCA Securities LLC and Wells Fargo Securities, LLC, as our sales agents, relating to common units representing limited partner interests offered by this prospectus supplement and the accompanying prospectus. In accordance with the terms of the equity distribution agreement, we may, through our sales agents, offer and sell from time to time our common units representing limited partner interests having an aggregate offering price of up to $750,000,000.

         Our common units trade on the New York Stock Exchange (NYSE) under the symbol "EQM." On August 26, 2015, the last sales price of the common units as reported on the NYSE was $75.14 per common unit.



         Sales of common units representing limited partner interests, if any, under this prospectus supplement and the accompanying prospectus may be made in negotiated transactions or transactions that are deemed to be "at the market" offerings as defined in Rule 415 under the Securities Act of 1933, as amended (the Securities Act), including sales made directly on the NYSE or sales made to or through a market maker other than on an exchange. Each of the sales agents will make all sales on a best efforts basis using commercially reasonable efforts consistent with its normal trading and sales practices, on mutually agreed terms between the sales agent and us.

         The compensation of each sales agent for sales of common units shall be at a fixed commission rate of up to 2% of the gross sales price per common unit. In connection with the sale of the common units on our behalf, each of the sales agents may be deemed to be an "underwriter" within the meaning of the Securities Act, and the compensation of the sales agents may be deemed to be underwriting commissions or discounts. Under the terms of the equity distribution agreement, we also may sell common units to one or more of the sales agents as principal for its own account at a price agreed upon at the time of the sale. If we sell common units to one or more of the sales agents as principal, we will enter into a separate agreement with the sales agent, and we will describe that agreement in a separate prospectus supplement or pricing supplement.

         Investing in the common units involves risks. You should carefully consider each of the risks factors described in the "Risk Factors" section on page S-3 of this prospectus supplement and page 2 of the accompanying base prospectus.

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



Deutsche Bank Securities   Barclays   BNP PARIBAS   BofA Merrill Lynch

Citigroup   Credit Suisse   Goldman, Sachs & Co.   J.P. Morgan

MUFG   RBC Capital Markets   Scotia Howard Weil

SunTrust Robinson Humphrey   U.S. Capital Advisors   Wells Fargo Securities

The date of this prospectus supplement is August 27, 2015


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Prospectus Supplement


Prospectus


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INFORMATION IN THIS PROSPECTUS SUPPLEMENT AND THE ACCOMPANYING PROSPECTUS

        This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of this offering of common units. The second part is the accompanying base prospectus, which gives more general information, some of which may not apply to this offering of common units. Generally, when we refer only to the "prospectus," we are referring to both this prospectus supplement and the accompanying base prospectus combined. If the information relating to the offering varies between this prospectus supplement and the accompanying base prospectus, you should rely on the information in this prospectus supplement.

        Any statement made in this prospectus or in a document incorporated or deemed to be incorporated by reference into this prospectus will be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus or in any other subsequently filed document that is also incorporated by reference into this prospectus modifies or supersedes that statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus. Please read "Information Incorporated by Reference" on page S-8 of this prospectus supplement.

        You should rely only on the information contained in or incorporated by reference into this prospectus supplement, the accompanying base prospectus and any free writing prospectus prepared by or on behalf of us relating to this offering of common units. Neither we nor the sales agents have authorized anyone to provide you with additional or different information. If anyone provides you with additional, different or inconsistent information, you should not rely on it. We are not, and the sales agents are not, making an offer to sell these securities in any jurisdiction where an offer or sale is not permitted. You should not assume that the information contained in this prospectus supplement, the accompanying base prospectus or any free writing prospectus is accurate as of any date other than the dates shown in these documents or that any information we have incorporated by reference herein is accurate as of any date other than the date of the document incorporated by reference. Our business, financial condition, results of operations and prospects may have changed since such dates.

        None of EQT Midstream Partners, LP, the sales agents or any of their respective representatives is making any representation to you regarding the legality of an investment in our common units by you under applicable laws. You should consult with your own advisors as to legal, tax, business, financial and related aspects of an investment in our common units.


DISCLOSURE REGARDING FORWARD-LOOKING STATEMENTS

        Some of the information included in this prospectus supplement, the accompanying base prospectus and the documents we incorporated by reference may contain forward-looking statements. Forward-looking statements give our current expectations, contain projections of results of operations and financial condition, or forecast future events. Words such as "anticipate," "estimate," "could," "would," "will," "may," "forecast," "approximate," "expect," "project," "intend," "plan," "believe" and similar expressions are used to identify forward-looking statements. Without limiting the generality of the foregoing, forward-looking statements contained in this prospectus supplement, the accompanying base prospectus and the documents we incorporated by reference include our expectations of plans, strategies, objectives, growth and anticipated financial and operational performance of us and our subsidiaries, including guidance regarding our transmission and storage and gathering revenue and volume growth; revenue projections; the weighted average contract life of transmission, storage and gathering contracts; infrastructure programs (including the timing, cost, capacity and sources of funding with respect to transmission and gathering expansion projects); the timing, cost, capacity and expected interconnections with facilities and pipelines of the Ohio Valley Connector and Mountain Valley Pipeline (MVP) projects; the ultimate terms, partners and structure of the MVP joint venture; natural

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gas production growth in our operating areas for EQT Corporation and third parties; asset acquisitions, including our ability to complete any asset acquisitions from EQT Corporation or third parties; the amount of cash flows resulting from our preferred interest in an EQT Corporation subsidiary; the amount and timing of distributions, including expected increases; the effect of the Allegheny Valley Connector (AVC) facilities lease on distributable cash flow; future projected AVC lease payments; projected operating and capital expenditures, including the amount of capital expenditures reimbursable by EQT Corporation; liquidity and financing requirements, including sources and availability; the effects of government regulation and litigation; and tax position. Forward-looking statements can be affected by assumptions used or by known or unknown risks or uncertainties. When considering forward-looking statements, you should keep in mind the risk factors and other cautionary statements in this prospectus supplement, the accompanying base prospectus and the documents we have incorporated by reference. Consequently, no forward-looking statement can be guaranteed.

        Please read "Risk Factors" on page S-3 of this prospectus supplement, page 2 of the accompanying base prospectus and in the documents incorporated by reference herein. The risk factors and other factors noted throughout this prospectus supplement, the accompanying base prospectus and in the documents incorporated by reference could cause our actual results to differ materially from those contained in any forward-looking statement. These factors include, but are not limited to, the following:

    changes in general economic conditions;

    competitive conditions in our industry;

    actions taken by third-party operators, processors, transporters and gatherers;

    changes in expected production from EQT Corporation and third parties in our areas of operation;

    changes in expected demand for natural gas storage, transportation and gathering services;

    our ability to successfully implement our business plan;

    our ability to complete organic growth projects on time and on budget;

    our ability to complete acquisitions from EQT Corporation or from third parties;

    the price and availability of debt and equity financing;

    the availability and price of natural gas to the consumer compared to the price of alternative and competing fuels;

    competition from the same and alternative energy sources;

    energy efficiency and technology trends;

    operating hazards and other risks incidental to transporting, storing and gathering natural gas;

    natural disasters, weather-related delays, casualty losses and other matters beyond our control;

    interest rates;

    labor relations;

    large customer defaults;

    changes in tax status;

    the effects of existing and future laws and governmental regulation;

    the effects of future litigation; and

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    certain factors discussed elsewhere in this prospectus supplement, the accompanying base prospectus and the documents incorporated by reference herein.

        Our forward-looking statements are not guarantees of future performance, and actual results and future performance may differ materially from those suggested in any forward-looking statement. We will not update these statements unless securities laws require us to do so.

        All subsequent written and oral forward-looking statements attributable to us or to persons acting on our behalf are expressly qualified in their entirety by the foregoing. We undertake no obligation to publicly release the results of any revisions to any such forward-looking statements that may be made to reflect events or circumstances after the date of this prospectus supplement or to reflect the occurrence of unanticipated events.

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SUMMARY

        This summary highlights information contained elsewhere in or incorporated by reference into this prospectus supplement and the accompanying base prospectus. This summary does not contain all of the information that you should consider before investing in our common units. You should read the entire prospectus supplement, the accompanying base prospectus and the documents incorporated herein by reference and other documents to which we refer for a more complete understanding of this offering. You should read "Risk Factors" beginning on page S-3 of this prospectus supplement and on page 2 of the accompanying base prospectus for more information about important risks that you should consider carefully before buying our common units.

        References in this prospectus supplement or the accompanying base prospectus to "EQT Midstream Partners," "the Partnership," "we," "our," "us" or like terms refer to EQT Midstream Partners, LP and its subsidiaries. References in this prospectus supplement or the accompanying base prospectus to "our general partner" refer to EQT Midstream Services, LLC, a wholly owned subsidiary of EQT GP Holdings, LP, which is an indirect subsidiary of EQT Corporation. References in this prospectus supplement or the accompanying base prospectus to "EQT" refer to EQT Corporation and its consolidated subsidiaries.


EQT MIDSTREAM PARTNERS, LP

Overview

        EQT Midstream Partners, LP (NYSE: EQM) is a growth-oriented limited partnership formed by EQT Corporation (NYSE: EQT) to own, operate, acquire and develop midstream assets in the Appalachian Basin. We provide substantially all of our natural gas transmission, storage and gathering services under contracts with long-term, firm reservation and/or usage fees. This contract structure enhances the stability of our cash flows and limits our direct exposure to commodity price risk. Our operations are primarily focused in southwestern Pennsylvania and northern West Virginia, a strategic location in the core of the rapidly growing natural gas shale plays known as the Marcellus Shale and the Utica Shale. This same region is also the core operating area of EQT, our largest customer. We provide midstream services to EQT and multiple third parties across 21 counties in Pennsylvania and West Virginia through our two primary assets: our transmission and storage system, which serves as a header system transmission pipeline, and our gathering system, which delivers natural gas from wells and other receipt points to transmission pipelines. We believe that our strategically located assets, combined with our working relationship with EQT, position us as a leading Appalachian Basin midstream energy company.

Principal Executive Offices and Internet Address

        Our principal executive offices are located at 625 Liberty Avenue, Suite 1700, Pittsburgh, Pennsylvania 15222, and our telephone number is (412) 553-5700. Our website is located at www.eqtmidstreampartners.com. We make available our periodic reports and other information filed with or furnished to the Securities and Exchange Commission (SEC) free of charge through our website, as soon as reasonably practicable after those reports and other information are electronically filed with or furnished to the SEC. Information on our website or any other website is not incorporated by reference herein and does not constitute a part of this prospectus.

 

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THE OFFERING

Common Units Offered by Us   Common units having an aggregate offering price of up to $750,000,000.

Use of Proceeds

 

We intend to use the net proceeds from the sale of the common units covered by this prospectus supplement for general partnership purposes, which may include, among other things, paying or refinancing all or a portion of our indebtedness outstanding at the time and funding working capital, capital expenditures or acquisitions. Affiliates of certain of the sales agents are lenders under our revolving credit facility. To the extent we use proceeds from this offering to repay indebtedness under our credit facility, such affiliates may receive proceeds from this offering. Please read "Use of Proceeds."

Material Tax Considerations

 

For a discussion of material federal income tax consequences that may be relevant to prospective unitholders who are individual citizens or residents of the United States, please read "Material Income Tax Considerations" in this prospectus supplement and in the accompanying base prospectus.

New York Stock Exchange Symbol

 

EQM.

Risk Factors

 

There are risks associated with this offering, our common units and our business. You should consider carefully the risk factors on page S-3 of this prospectus supplement and the other risks identified in the documents incorporated by reference herein before making a decision to purchase common units in this offering.

 

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RISK FACTORS

        Our business is subject to uncertainties and risks. Before you invest in our common units, you should carefully consider the risk factors beginning on page 2 of the accompanying base prospectus and those included in our annual report on Form 10-K for the year ended December 31, 2014, as updated by any subsequent quarterly reports on Form 10-Q, which are incorporated by reference into this prospectus supplement, together with all of the other information included in this prospectus supplement, the accompanying base prospectus and the documents we incorporate by reference. If any of the events or circumstances discussed in the foregoing documents actually occurs, our business, financial condition, results of operations, liquidity or ability to make distributions could suffer and you could lose all or part of your investment. Please also read "Disclosure Regarding Forward-Looking Statements."

Risks Related to Our Common Units

         The price of our common units may be adversely affected by the future issuance and sale of additional common units, including pursuant to the equity distribution agreement, or by our announcement that such issuances and sales may occur.

        We cannot predict the size of future issuances or sales of our common units, including those made pursuant to the equity distribution agreement with any of our sales agents or in connection with future acquisitions or capital raising activities, or the effect, if any, that such issuances or sales may have on the market price of our common units. In addition, the sales agents will not engage in any transactions that stabilize the price of our common units in connection with this offering. The issuance and sale of substantial amounts of common units, including issuances and sales pursuant to the equity distribution agreement, or announcement that such issuances and sales may occur, could adversely affect the market price of our common units.

Tax Risks to Common Unitholders

         We prorate our items of income, gain, loss and deduction for U.S. federal income tax purposes between transferors and transferees of our units each month based upon the ownership of our units on the first day of each month, instead of on the basis of the date a particular unit is transferred. The Internal Revenue Service (IRS) may challenge this treatment, which could change the allocation of items of income, gain, loss and deduction among our unitholders.

        We prorate our items of income, gain, loss and deduction for U.S. federal income tax purposes between transferors and transferees of our units each month based upon the ownership of our units on the first day of each month, instead of on the basis of the date a particular unit is transferred. Although simplifying conventions are contemplated by the Internal Revenue Code of 1986, as amended (the Code) and most publicly traded partnerships use similar simplifying conventions, the use of this method may not be permitted under existing and proposed Treasury regulations promulgated under the Code (the Treasury Regulations), and although the U.S. Department of the Treasury recently adopted final Treasury Regulations allowing a similar monthly simplifying convention for taxable years beginning on or after August 3, 2015, such regulations do not specifically authorize the use of the proration method we have adopted. Accordingly, our counsel is unable to opine as to the validity of this method. If the IRS were to challenge this method or new Treasury Regulations were issued, we may be required to change the allocation of items of income, gain, loss and deduction among our unitholders. Our counsel has not rendered an opinion with respect to whether our monthly convention for allocating taxable income and losses is permitted by existing Treasury Regulations.

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USE OF PROCEEDS

        We intend to use the net proceeds from this offering, after deducting the sales agents' commissions and our offering expenses, for general partnership purposes, which may include, among other things, paying or refinancing all or a portion of our indebtedness outstanding at the time and funding working capital, capital expenditures or acquisitions.

        Affiliates of certain of the sales agents are lenders under our revolving credit facility. To the extent we use proceeds from this offering to repay indebtedness under our credit facility, such affiliates may receive proceeds from this offering. Please read "Plan of Distribution" in this prospectus supplement for further information.

        At June 30, 2015, we had $312 million of borrowings outstanding under our revolving credit facility. Interest was incurred on the outstanding borrowings at a weighted average interest rate of 1.69% for the six months ended June 30, 2015. The revolving credit facility expires in February 2019. Substantially all of the borrowings were used to fund acquisitions, working capital and internal growth projects and for general partnership purposes.

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MATERIAL INCOME TAX CONSIDERATIONS

        The tax consequences to you of an investment in our common units will depend in part on your own tax circumstances. Although this section updates and adds information related to certain tax considerations associated with our operations and the purchase, ownership and disposition of our common units, it should be read in conjunction with the risk factors included under the caption "Tax Risks to Common Unitholders" in our annual report on Form 10-K for the year ended December 31, 2014 and "Material Income Tax Considerations" in the accompanying base prospectus, as well as the other information contained in or incorporated by reference herein and therein. You are urged to consult with your own tax advisor about the federal, state, local and foreign tax consequences particular to your circumstances.

Allocations Between Transferors and Transferees

        In general, our taxable income and losses will be determined annually, will be prorated on a monthly basis and will be subsequently apportioned among the unitholders in proportion to the number of units owned by each of them as of the opening of the applicable exchange on the first business day of the month, which we refer to in this prospectus as the "Allocation Date." However, gain or loss realized on a sale or other disposition of our assets other than in the ordinary course of business will be allocated among the unitholders on the Allocation Date in the month in which that gain or loss is recognized. As a result, a unitholder transferring units may be allocated income, gain, loss and deduction realized after the date of transfer.

        Although simplifying conventions are contemplated by the Code and most publicly traded partnerships use similar simplifying conventions, the use of this method may not be permitted under existing Treasury Regulations. Even though the Department of the Treasury and the IRS have recently adopted finalized Treasury Regulations under Section 706 of the Code that allow a publicly traded partnership to use a similar monthly simplifying convention to allocate tax items among transferor and transferee unitholders, the final regulations do not specifically authorize the use of the proration method we have adopted. Accordingly, Baker Botts L.L.P. is unable to opine on the validity of this method of allocating income and deductions between transferor and transferee unitholders. If this method is not allowed under the Treasury Regulations, or only applies to transfers of less than all of the unitholder's interest, our taxable income or losses might be reallocated among the unitholders. We are authorized to revise our method of allocation between transferor and transferee unitholders, as well as unitholders whose interests vary during a taxable year, to conform to a method permitted under the Treasury Regulations.

        A unitholder who disposes of units prior to the record date set for a cash distribution for any quarter will be allocated items of our income, gain, loss and deductions attributable to the month of sale but will not be entitled to receive that cash distribution.

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PLAN OF DISTRIBUTION

        We have entered into an equity distribution agreement with Deutsche Bank Securities Inc., Barclays Capital Inc., BNP Paribas Securities Corp., Merrill Lynch, Pierce, Fenner & Smith Incorporated, Citigroup Global Markets Inc., Credit Suisse Securities (USA) LLC, Goldman, Sachs & Co., J.P. Morgan Securities LLC, Mitsubishi UFJ Securities (USA), Inc., RBC Capital Markets, LLC, Scotia Capital (USA) Inc., SunTrust Robinson Humphrey, Inc., USCA Securities LLC and Wells Fargo Securities, LLC, as sales agents, under which we are permitted to offer and sell common units having an aggregate offering price of up to $750,000,000 from time to time through one or more of such sales agents. We have filed the equity distribution agreement as an exhibit to a Current Report on Form 8-K, which is incorporated by reference in this prospectus supplement. The sales, if any, of common units made under the equity distribution agreement will be made by means of ordinary broker transactions on the NYSE at market prices, in block transactions, or as otherwise agreed upon by the sales agents and us. The sales agents will not engage in any transactions that stabilize the price of our common units in connection with this offering.

        Under the terms of the equity distribution agreement, we also may sell common units to one or more of the sales agents as principal for its own account at a price agreed upon at the time of sale. If we sell common units to one or more of the sales agents as principal, we will enter into a separate agreement with the sales agent and we will describe such agreement in a separate prospectus supplement or pricing supplement.

        We will designate the maximum amount of common units to be sold through the sales agents and the minimum price per common unit at which such common units may be sold. Subject to the terms and conditions of the equity distribution agreement, the sales agents will use their commercially reasonable efforts to sell on our behalf all of the designated common units. We may instruct the sales agents not to sell any common units if the sales cannot be effected at or above the price designated by us in any such instruction. We or any of the sales agents may suspend the offering of common units at any time and from time to time by notifying the other party.

        Each sales agent will provide written confirmation to us following the close of trading on the NYSE each day on which common units are sold by it as our agent under the equity distribution agreement. Each confirmation will include the number of common units sold under the equity distribution agreement on such day, the gross offering proceeds received from such sales, and the commission payable by us to such sales agent with respect to such sales. We will report at least quarterly the number of common units sold through the sales agents under the equity distribution agreement, the net proceeds to us (before expenses) and the compensation paid by us to the sales agents in connection with the sales of the common units.

        We will pay each sales agent a commission of up to 2.0% of the gross sales price per common unit sold through such agent as our agent under the equity distribution agreement. We have also agreed to reimburse the sales agents for certain of their expenses.

        Settlement for sales of common units will occur on the third business day following the date on which any sales were made in return for payment of the net proceeds to us. There is no arrangement for funds to be received in an escrow, trust or similar arrangement.

        If we or any of the sales agents have reason to believe that our common units are no longer an "actively-traded security" as defined under Rule 101(c)(l) of Regulation M under the Securities Exchange Act of 1934, as amended (the Exchange Act), that party will promptly notify the others and sales of common units pursuant to the equity distribution agreement or any terms agreement will be suspended until in our collective judgment Rule 101(c)(1) or another exemptive provision has been satisfied.

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        The offering of common units pursuant to the equity distribution agreement will terminate upon the earlier of (1) the sale of all common units subject to the equity distribution agreement or (2) the termination of the equity distribution agreement by us or by each of the sales agents.

        In connection with the sale of the common units on our behalf, the sales agent may be deemed to be an "underwriter" within the meaning of the Securities Act, and the compensation paid to each of the sales agents may be deemed to be underwriting commissions or discounts. We have agreed to provide indemnification and contribution to the sales agents against certain liabilities, including civil liabilities under the Securities Act.

Relationships/FINRA Conduct Rules

        From time to time, the sales agents and their affiliates have provided, directly or indirectly, investment and commercial banking or financial advisory services to us and our affiliates, for which they have received customary fees and commissions, and they expect to provide these services to us and our affiliates in the future, for which they expect to receive customary fees and commissions. Affiliates of certain of the sales agents are lenders under our revolving credit facility. To the extent we use proceeds from this offering to repay indebtedness under our credit facility, such affiliates may receive proceeds from this offering.

        In compliance with the guidelines of the Financial Industry Regulatory Authority, Inc. (FINRA), the maximum discount or commission to be received by any FINRA member or independent broker-dealer may not exceed 8% of the aggregate offering price of the common units offered pursuant to this prospectus supplement. Because FINRA views the common units offered hereby as interests in a direct participation program, this offering is being made in compliance with Rule 2310 of the FINRA Rules.

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LEGAL MATTERS

        The validity of the common units will be passed upon for us by Baker Botts L.L.P., Houston, Texas. Certain legal matters in connection with the common units offered hereby will be passed upon for the sales agents by Vinson & Elkins L.L.P., Houston, Texas.


EXPERTS

        The combined financial statements of EQT Midstream Partners, LP as of December 31, 2014 and 2013, and for each of the years in the three-year period ended December 31, 2014, appearing in EQT Midstream Partners, LP's Current Report on Form 8-K filed on April 1, 2015, and the effectiveness of EQT Midstream Partners, LP's internal control over financial reporting as of December 31, 2014 included in its Annual Report on Form 10-K, have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their reports thereon, included therein, and incorporated by reference herein. Such financial statements are, and audited financial statements to be included in subsequently filed documents will be, incorporated herein in reliance upon the reports of Ernst & Young LLP pertaining to such financial statements and the effectiveness of our internal control over financial reporting as of the respective dates (to the extent covered by consents filed with the SEC) given on the authority of Ernst & Young LLP as experts in accounting and auditing.


AVAILABLE INFORMATION

        We file annual, quarterly and other reports and other information with the SEC under the Exchange Act. You may read and copy any document we file at the SEC's public reference room at 100 F Street, N.E., Washington, D.C. 20549. Please call the SEC at 1-800-732-0330 for further information on the operation of the SEC's public reference room. Our SEC filings are available on the SEC's website at www.sec.gov. We also make available free of charge on our website at www.eqtmidstreampartners.com all materials that we file electronically with the SEC, including our annual report on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, Section 16 reports and amendments to these reports as soon as reasonably practicable after such materials are electronically filed with, or furnished to, the SEC. Information contained on our website or any other website, other than the documents listed below, is not incorporated by reference into this prospectus and does not constitute a part of this prospectus.


INFORMATION INCORPORATED BY REFERENCE

        The SEC allows us to "incorporate by reference" the information we have filed with the SEC. This means that we can disclose important information to you without actually including the specific information in this prospectus by referring you to other documents filed separately with the SEC. These other documents contain important information about us, our financial condition and results of operations. The information incorporated by reference is an important part of this prospectus. Information that we file later with the SEC will automatically update and may replace information in this prospectus and information previously filed with the SEC.

        We incorporate by reference in this prospectus supplement the documents listed below and any subsequent filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (excluding information deemed to be furnished and not filed with the SEC) until all offerings under this registration statement are completed:

    our annual report on Form 10-K for the year ended December 31, 2014;

    our quarterly reports on Form 10-Q for the quarters ended March 31, 2015 and June 30, 2015;

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    our current reports on Form 8-K filed on January 22, 2015, March 10, 2015, March 17, 2015, March 31, 2015, April 1, 2015, May 15, 2015, August 10, 2015 and August 27, 2015 (in each case to the extent filed and not furnished); and

    the description of our common units in our registration statement on Form 8-A (File No. 001-35574) filed on June 18, 2012.

        You may obtain any of the documents incorporated by reference in this prospectus from the SEC through the SEC's website at the address provided above. You also may request a copy of any document incorporated by reference in this prospectus (including exhibits to those documents specifically incorporated by reference in those documents), at no cost, by visiting our website at www.eqtmidstreampartners.com, or by writing or calling us at the following address:

EQT Midstream Partners, LP
625 Liberty Avenue, Suite 1700
Pittsburgh, Pennsylvania 15222
Attention: Investor Relations
Telephone: (412) 553-5700

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PROSPECTUS

LOGO

EQT Midstream Partners, LP

COMMON UNITS

        We may offer and sell up to $750,000,000 in aggregate offering price of common units representing limited partner interests in EQT Midstream Partners, LP from time to time and in amounts, at prices and on terms to be determined by market conditions and other factors at the time of our offerings.

        We may offer and sell these securities through one or more underwriters, dealers or agents, or directly to purchasers, on a continuous or delayed basis. See "Plan of Distribution."

        This prospectus describes only the general terms of these common units and the general manner in which we will offer the common units. The specific terms of any common units we offer will be included in a supplement to this prospectus. The prospectus supplement will describe the specific manner in which we will offer the common units and also may add, update or change information contained in this prospectus.

        Our common units are traded on the New York Stock Exchange under the symbol "EQM."

        Investing in our securities involves risks. You should carefully consider the risk factors described under "Risk Factors" on page 2 of this prospectus before you make any investment in our securities.

        Neither the Securities and Exchange Commission nor any other regulatory body 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.

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        You should rely only on the information we have provided or incorporated by reference in this prospectus. We have not authorized any person to provide you with additional or different information. You should not assume that the information in this prospectus is accurate as of any date other than the date on the cover page of this prospectus or that any information we have incorporated by reference is accurate as of any date other than the date of the documents incorporated by reference. Our business, financial condition, results of operations and prospects may have changed since those dates.

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ABOUT THIS PROSPECTUS

        This prospectus is part of a registration statement on Form S-3 that we have filed with the Securities and Exchange Commission (the SEC) using a "shelf" registration process. Under this shelf registration process, we may, from time to time, sell up to $750,000,000 in total aggregate offering price of our common units described in this prospectus in one or more offerings. This prospectus provides you with a general description of us and the common units offered under this prospectus.

        Each time we sell securities under this prospectus, we will provide a prospectus supplement that will contain specific information about the terms of that offering and the securities being offered. The prospectus supplement also may add to, update or change information in this prospectus. If there is any inconsistency between the information in this prospectus and any prospectus supplement, you should rely on the information in the prospectus supplement. You should read carefully this prospectus, any prospectus supplement and the additional information described below under the heading "Where You Can Find More Information."

        This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by reference to the actual documents. For additional information about our business, operations and financial results, please read the documents incorporated by reference herein as described below in the section entitled "Where You Can Find More Information."

        As used in this prospectus, "we," "us" and "our" and similar terms mean EQT Midstream Partners, LP and its subsidiaries, unless the context indicates otherwise. References in this prospectus to "our general partner" refer to EQT Midstream Services, LLC, a wholly owned subsidiary of EQT GP Holdings, LP, which we refer to herein as "EQGP." References in this prospectus to "EQT" refer to EQT Corporation and its consolidated subsidiaries.


EQT MIDSTREAM PARTNERS, LP

        EQT Midstream Partners, LP (NYSE: EQM) is a growth-oriented limited partnership formed by EQT Corporation (NYSE: EQT) to own, operate, acquire and develop midstream assets in the Appalachian Basin. We provide substantially all of our natural gas transmission, storage and gathering services under contracts with long-term, firm reservation and/or usage fees. Our operations are primarily focused in southwestern Pennsylvania and northern West Virginia, a strategic location in the core of the rapidly growing natural gas shale play known as the Marcellus Shale. This same region is also the core operating area of EQT, our largest customer. We provide midstream services to EQT and multiple third parties across 21 counties in Pennsylvania and West Virginia through our two primary assets: our transmission and storage system, which serves as a header system transmission pipeline, and our gathering system, which delivers natural gas from wells and other receipt points to transmission pipelines.

        Our general partner, EQT Midstream Services, LLC, is a Delaware limited liability company and has ultimate responsibility for conducting our business and managing our operations.

        Our executive offices are located at 625 Liberty Avenue, Suite 1700, Pittsburgh, Pennsylvania 15222, and our telephone number is (412) 553-5700.

        For more information as to our business, properties and financial condition, please refer to the documents cited in "Where You Can Find More Information."

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RISK FACTORS

        An investment in our securities involves a high degree of risk. You should carefully consider the risks described in our filings with the SEC referred to under the heading "Where You Can Find More Information," as well as the risks included and incorporated by reference in this prospectus, including the risk factors incorporated by reference herein from our most recent Annual Report on Form 10-K, as updated by annual, quarterly and other reports and documents we file with the SEC after the date of this prospectus and that are incorporated by reference herein. If any of these risks were to occur, our business, financial condition or results of operations could be adversely affected. In that case, the trading price of our common units could decline and you could lose all or part of your investment. When we offer and sell any securities pursuant to a prospectus supplement, we may include additional risk factors relevant to such securities in the prospectus supplement.


FORWARD-LOOKING STATEMENTS

        Some of the information included in this prospectus, any prospectus supplement and the documents we incorporate by reference may contain forward-looking statements. Forward-looking statements give our current expectations, contain projections of results of operations or of financial condition, or forecast future events. Words such as "anticipate," "estimate," "could," "would," "will," "may," "forecast," "approximate," "expect," "project," "intend," "plan," "believe" and similar expressions are used to identify forward-looking statements. The forward-looking statements included in this prospectus involve risks and uncertainties that could cause actual results to differ materially from projected results. Accordingly, you should not place undue reliance on forward-looking statements as a prediction of actual results. We have based these forward-looking statements on current expectations and assumptions about future events. While we consider these expectations and assumptions to be reasonable, they are inherently subject to significant business, economic, competitive, regulatory and other risks and uncertainties, many of which are difficult to predict and are beyond our control. The risks and uncertainties that may affect the operations, performance and results of our business and forward-looking statements include, but are not limited to, those set forth under the "Risk Factors" section of this prospectus and in the documents that we have incorporated by reference herein.

        Additionally, factors that could cause our actual results to differ materially from the results contemplated by such forward-looking statements include:

    changes in general economic conditions;

    competitive conditions in our industry;

    actions taken by third-party operators, processors, transporters and gatherers;

    changes in expected production from EQT and third parties in our areas of operation;

    changes in expected demand for natural gas storage, transportation and gathering services;

    our ability to successfully implement our business plan;

    our ability to complete organic growth projects on time and on budget;

    our ability to complete acquisitions from EQT or from third parties;

    the price and availability of debt and equity financing;

    the availability and price of natural gas to the consumer compared to the price of alternative and competing fuels;

    competition from the same and alternative energy sources;

    energy efficiency and technology trends;

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    operating hazards and other risks incidental to transporting, storing and gathering natural gas;

    natural disasters, weather-related delays, casualty losses and other matters beyond our control;

    interest rates;

    labor relations;

    large customer defaults;

    changes in tax status;

    the effects of existing and future laws and governmental regulation;

    the effects of future litigation; and

    certain factors discussed elsewhere in this prospectus and the documents incorporated by reference herein.

        Our forward-looking statements are not guarantees of future performance, and actual results and future performance may differ materially from those suggested in any forward-looking statement. We will not update these statements unless securities laws require us to do so.

        In reviewing any agreements incorporated by reference in or filed with the registration statement of which this prospectus forms a part, please remember that such agreements are included to provide information regarding the terms of such agreements and are not intended to provide any other factual or disclosure information about us. The agreements may contain representations and warranties by us, which should not in all instances be treated as categorical statements of fact, but rather as a way of allocating the risk to one of the parties to such agreements should those statements prove to be inaccurate. The representations and warranties were made only as of the date of the relevant agreement or such other date or dates as may be specified in such agreement and are subject to more recent developments. Accordingly, these representations and warranties alone may not describe the actual state of affairs of us or our affiliates as of the date they were made or at any other time.

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USE OF PROCEEDS

        Unless we specify otherwise in any prospectus supplement, we will use the net proceeds we receive from the sale of securities covered by this prospectus for general partnership purposes, which may include, among other things:

    paying or refinancing all or a portion of our indebtedness outstanding at the time; and

    funding working capital, capital expenditures or acquisitions.

        The actual application of proceeds from the sale of any particular offering of securities using this prospectus will be described in the applicable prospectus supplement relating to such offering. The precise amount and timing of the application of these proceeds will depend upon our funding requirements and the availability and cost of other funds.

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DESCRIPTION OF THE COMMON UNITS

        The common units represent limited partner interests in us that entitle the holders to participate in our cash distributions and to exercise the rights or privileges available to limited partners under our partnership agreement. For a description of the relative rights and preferences of holders of common units in and to partnership distributions, see "Cash Distribution Policy" in this prospectus. For a description of the rights and privileges of limited partners under our partnership agreement, including voting rights, please read "Description of Our Partnership Agreement." For a general discussion of the expected federal income tax consequences of owning and disposing of common units, see "Material Income Tax Considerations." References in this "Description of the Common Units" to "we," "us" and "our" mean EQT Midstream Partners, LP.

        Our outstanding common units are traded on the New York Stock Exchange under the symbol "EQM."

Transfer Agent and Registrar

    Duties

        American Stock Transfer & Trust Company, LLC serves as registrar and transfer agent for our common units. We will pay all fees charged by the transfer agent for transfers of common units except the following that must be paid by unitholders:

    surety bond premiums to replace lost or stolen certificates, taxes and other governmental charges;

    special charges for services requested by a common unitholder; and

    other similar fees or charges.

        There will be no charge to unitholders for disbursements of our cash distributions. We will indemnify the transfer agent, its agents and each of their stockholders, directors, officers and employees against all claims and losses that may arise out of acts performed or omitted for its activities in that capacity, except for any liability due to any gross negligence or intentional misconduct of the indemnified person or entity.

    Resignation or Removal

        The transfer agent may resign by notice to us or be removed by us. The resignation or removal of the transfer agent will become effective upon our appointment of a successor transfer agent and registrar and its acceptance of the appointment. If no successor has been appointed and has accepted the appointment within 30 days after notice of the resignation or removal, our general partner may act as the transfer agent and registrar until a successor is appointed.

Transfer of Common Units

        By transfer of common units in accordance with our partnership agreement, each transferee of common units shall be admitted as a limited partner with respect to the common units transferred when such transfer or admission is reflected in our register and such limited partner becomes the record holder of the common units so transferred. Each transferee, whether or not such transferee executes our partnership agreement:

    will become bound and will be deemed to have agreed to be bound by the terms and conditions of our partnership agreement;

    represents that the transferee has the capacity, power and authority to enter into our partnership agreement; and

    makes the consents, acknowledgements and waivers contained in our partnership agreement.

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        We are entitled to treat the nominee holder of a common unit as the absolute owner in the event such nominee is the record holder of such common unit. In that case, the beneficial holder's rights are limited solely to those that it has against the nominee holder as a result of any agreement between the beneficial owner and the nominee holder.

        Common units are securities and are transferable according to the laws governing transfer of securities. Until a common unit has been transferred on our register, we and the transfer agent may treat the record holder of the unit as the absolute owner for all purposes, except as otherwise required by law or stock exchange regulations.

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DESCRIPTION OF OUR PARTNERSHIP AGREEMENT

        The following is a summary of the material provisions of our partnership agreement. Our partnership agreement and the amendments thereto are included as exhibits to the registration statement of which this prospectus constitutes a part. We summarize certain other provisions of the partnership agreement elsewhere in this prospectus, including in "Description of the Common Units," "Cash Distribution Policy" and "Material Income Tax Considerations."

Organization and Duration

        Our partnership was organized on January 18, 2012 and will have a perpetual existence unless terminated pursuant to the terms of our partnership agreement.

Purpose

        Our purpose under the partnership agreement is limited to any business activity that is approved by our general partner and that lawfully may be conducted by a limited partnership organized under Delaware law; provided that our general partner shall not cause us to engage, directly or indirectly, in any business activity that our general partner determines would be reasonably likely to cause us to be treated as an association taxable as a corporation or otherwise taxable as an entity for federal income tax purposes.

        Although our general partner has the ability to cause us and our subsidiaries to engage in activities other than the business of transporting, storing and gathering natural gas, our general partner has no current plans to do so and may decline to do so free of any duty or obligation whatsoever to us or the limited partners, including any duty to act in the best interests of us or the limited partners, other than the implied contractual covenant of good faith and fair dealing. Our general partner is authorized in general to perform all acts it determines to be necessary or appropriate to carry out our purposes and to conduct our business.

Capital Contributions

        Unitholders are not obligated to make additional capital contributions, except as described below under "—Limited Liability."

        For a discussion of our general partner's right to contribute capital to maintain its 2.0% general partner interest if we issue additional units, please read "—Issuance of Additional Partnership Interests."

Voting Rights

        The following is a summary of the unitholder vote required for the matters specified below. Our general partner units are not deemed outstanding units for purposes of voting rights and such units represent a non-voting general partner interest in us. Matters requiring the approval of a "unit majority" require the approval of a majority of our outstanding common units.

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        In voting their common units, our general partner and its affiliates will have no duty or obligation whatsoever to us or the limited partners, including any duty to act in the best interests of us or the limited partners, other than the implied contractual covenant of good faith and fair dealing.

Issuance of additional units

  No approval right.

Amendment of the partnership agreement

 

Certain amendments may be made by the general partner without the approval of the unitholders. Other amendments generally require the approval of a unit majority. Please read "—Amendment of the Partnership Agreement."

Merger of our partnership or the sale of all or substantially all of our assets

 

Unit majority in certain circumstances. Please read "—Merger, Consolidation, Conversion, Sale or Other Disposition of Assets."

Dissolution of our partnership

 

Unit majority. Please read "—Dissolution."

Continuation of our business upon dissolution

 

Unit majority. Please read "—Dissolution."

Withdrawal of the general partner

 

Under most circumstances, the approval of unitholders holding at least a majority of the outstanding common units, excluding common units held by our general partner and its affiliates, is required for the withdrawal of our general partner prior to June 30, 2022 in a manner that would cause a dissolution of our partnership. Please read "—Withdrawal or Removal of the General Partner."

Removal of the general partner

 

Not less than 662/3% of the outstanding units, voting as a single class, including units held by our general partner and its affiliates. Please read "—Withdrawal or Removal of the General Partner."

Transfer of the general partner interest

 

Our general partner may transfer all, but not less than all, of its general partner interest in us without a vote of our unitholders to an affiliate or another person in connection with its merger or consolidation with or into, or sale of all or substantially all of its assets to, such person. The approval of a majority of the outstanding common units, excluding common units held by our general partner and its affiliates, is required in other circumstances for a transfer of the general partner interest to a third party prior to June 30, 2022. Please read "—Transfer of General Partner Units."

Transfer of incentive distribution rights

 

Our general partner may transfer any or all of the incentive distribution rights without a vote of our unitholders to an affiliate or another person. Please read "—Transfer of Incentive Distribution Rights."

Reset of incentive distribution levels

 

No approval right.

Transfer of ownership interests in our general partner

 

No approval right. Please read "—Transfer of Ownership Interests in the General Partner."

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Limited Liability

        Assuming that a limited partner does not participate in the control of our business within the meaning of the Delaware Revised Uniform Limited Partnership Act, as amended (the Delaware Act), and that he otherwise acts in conformity with the provisions of the partnership agreement, his liability under the Delaware Act will be limited, subject to possible exceptions, to the amount of capital he is obligated to contribute to us for his common units plus his share of any undistributed profits and assets. If it were determined, however, that the right, or exercise of the right, by the limited partners as a group:

    to remove or replace the general partner;

    to approve some amendments to the partnership agreement; or

    to take other action under the partnership agreement;

constituted "participation in the control" of our business for the purposes of the Delaware Act, then the limited partners could be held personally liable for our obligations under the laws of Delaware, to the same extent as the general partner. This liability would extend to persons who transact business with us who reasonably believe that the limited partner is a general partner. Neither the partnership agreement nor the Delaware Act specifically provides for legal recourse against the general partner if a limited partner were to lose limited liability through any fault of the general partner. While this does not mean that a limited partner could not seek legal recourse, we know of no precedent for this type of a claim in Delaware case law.

        Under the Delaware Act, a limited partnership may not make a distribution to a partner if, after the distribution, all liabilities of the limited partnership, other than liabilities to partners on account of their limited partner interests and liabilities for which the recourse of creditors is limited to specific property of the partnership, would exceed the fair value of the assets of the limited partnership, except that the fair value of property that is subject to a liability for which the recourse of creditors is limited is included in the assets of the limited partnership only to the extent that the fair value of that property exceeds that liability. For the purpose of determining the fair value of the assets of a limited partnership, the Delaware Act provides that the fair value of property subject to liability for which recourse of creditors is limited shall be included in the assets of the limited partnership only to the extent that the fair value of that property exceeds the non-recourse liability. The Delaware Act provides that a limited partner who receives a distribution and knew at the time of the distribution that the distribution was in violation of the Delaware Act shall be liable to the limited partnership for the amount of the distribution for three years. Under the Delaware Act, a substituted limited partner of a limited partnership is liable for the obligations of his assignor to make contributions to the partnership, except that such person is not obligated for liabilities unknown to him at the time he became a limited partner and that could not be ascertained from the partnership agreement.

        Our subsidiaries conduct business in several states and we may have subsidiaries that conduct business in other states in the future. Maintenance of our limited liability as a limited partner of our operating subsidiaries may require compliance with legal requirements in the jurisdictions in which our operating subsidiaries conduct business, including qualifying our subsidiaries to do business there.

        Limitations on the liability of limited partners or members for the obligations of a limited partnership or limited liability company have not been clearly established in many jurisdictions. If, by virtue of our limited partner interest in our operating subsidiaries or otherwise, it were determined that we were conducting business in any state without compliance with the applicable limited partnership or limited liability company statute, or that the right or exercise of the right by the limited partners as a group to remove or replace the general partner, to approve some amendments to the partnership agreement, or to take other action under the partnership agreement constituted "participation in the control" of our business for purposes of the statutes of any relevant jurisdiction, then the limited

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partners could be held personally liable for our obligations under the law of that jurisdiction to the same extent as the general partner under the circumstances. We will operate in a manner that the general partner considers reasonable and necessary or appropriate to preserve the limited liability of the limited partners.

Issuance of Additional Partnership Interests

        Our partnership agreement authorizes us to issue an unlimited number of additional partnership interests for the consideration and on the terms and conditions determined by our general partner without the approval of the unitholders.

        It is possible that we will fund acquisitions through the issuance of additional common units or other partnership interests. Holders of any additional common units we issue will be entitled to share equally with the then-existing holders of common units in our distributions of available cash. In addition, the issuance of additional common units or other partnership interests may dilute the value of the interests of the then-existing holders of common units in our net assets.

        In accordance with Delaware law and the provisions of our partnership agreement, we may also issue additional partnership interests that, as determined by our general partner, may have special voting rights to which the common units are not entitled. In addition, our partnership agreement does not prohibit the issuance by our subsidiaries of equity interests, which may effectively rank senior to the common units.

        Upon issuance of additional limited partner interests (other than the issuance of common units in connection with a reset of the incentive distribution target levels or the issuance of common units upon conversion of outstanding partnership interests), our general partner will be entitled, but not required, to elect to maintain its 2.0% general partner interest in us, which election will be immediately effective. In the event of such an election, our general partner will be required, upon our demand, but in any case no later than the record date for the distribution of available cash with respect to the quarter in which such election is made, to contribute a proportionate amount of capital to us to the extent necessary to maintain its 2.0% general partner interest. Our general partner's 2.0% interest in us will be reduced if we issue additional units in the future and our general partner does not elect to maintain its 2.0% general partner interest. Moreover, our general partner will have the right, which it may from time to time assign in whole or in part to any of its affiliates, to purchase common units or other partnership interests whenever, and on the same terms that, we issue those interests to persons other than our general partner and its affiliates, to the extent necessary to maintain the percentage interest of the general partner and its affiliates, including such interest represented by common units, that existed immediately prior to each issuance. The other holders of common units will not have preemptive rights to acquire additional common units or other partnership interests.

Amendment of the Partnership Agreement

    General

        Amendments to our partnership agreement may be proposed only by our general partner. However, our general partner will have no duty or obligation to propose any amendment and may decline to do so free of any duty or obligation whatsoever to us or the limited partners, including any duty to act in the best interests of us or the limited partners, other than the implied contractual covenant of good faith and fair dealing. In order to adopt a proposed amendment, other than the amendments discussed below, our general partner is required to seek written approval of the holders of the number of units required to approve the amendment or call a meeting of the limited partners to consider and vote upon the proposed amendment. Except as described below, an amendment must be approved by a unit majority.

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    Prohibited Amendments

        No amendment may be made that would:

    enlarge the obligations of any limited partner without its consent, unless such is deemed to have occurred as a result of an amendment approved by at least a majority of the type or class of limited partner interests so affected; or

    enlarge the obligations of, restrict in any way any action by or rights of, or reduce in any way the amounts distributable, reimbursable or otherwise payable by us to our general partner or any of its affiliates without its consent, which consent may be given or withheld at its option.

        The provisions of our partnership agreement preventing the amendments having the effects described in any of the clauses above can be amended upon the approval of the holders of at least 90% of the outstanding units voting together as a single class (including units owned by our general partner and its affiliates).

    No Unitholder Approval

        Our general partner may generally make amendments to our partnership agreement without the approval of any limited partner to reflect:

    a change in our name, the location of our principal office, our registered agent or our registered office;

    the admission, substitution, withdrawal or removal of partners in accordance with our partnership agreement;

    a change that our general partner determines to be necessary or appropriate to qualify or continue our qualification as a limited partnership or a partnership in which the limited partners have limited liability under the laws of any state or to ensure that neither we nor any of our subsidiaries will be treated as an association taxable as a corporation or otherwise taxed as an entity for federal income tax purposes;

    an amendment that is necessary, in the opinion of our counsel, to prevent us or our general partner or its directors, officers, agents or trustees from, in any manner, being subjected to the provisions of the Investment Company Act of 1940, the Investment Advisors Act of 1940, or "plan asset" regulations adopted under the Employee Retirement Income Security Act of 1974, or ERISA, whether or not substantially similar to plan asset regulations currently applied or proposed by the United States Department of Labor;

    an amendment that our general partner determines to be necessary or appropriate for the authorization or issuance of additional partnership interests;

    any amendment expressly permitted in our partnership agreement to be made by our general partner acting alone;

    an amendment effected, necessitated or contemplated by a merger agreement that has been approved under the terms of our partnership agreement;

    any amendment that our general partner determines to be necessary or appropriate to reflect and account for the formation by us of, or our investment in, any corporation, partnership or other entity, in connection with our conduct of activities permitted by our partnership agreement;

    a change in our fiscal year or taxable year and any other changes that our general partner determines to be necessary or appropriate as a result of such change;

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    conversions into, mergers with or conveyances to another limited liability entity that is newly formed and has no assets, liabilities or operations at the time of the conversion, merger or conveyance other than those it receives by way of the conversion, merger or conveyance; or

    any other amendments substantially similar to any of the matters described in the clauses above.

        In addition, our general partner may make amendments to our partnership agreement without the approval of any limited partner if our general partner determines that those amendments:

    do not adversely affect in any material respect the limited partners considered as a whole or any particular class of partnership interests as compared to other classes of partnership interests;

    are necessary or appropriate to satisfy any requirements, conditions or guidelines contained in any opinion, directive, order, ruling or regulation of any federal or state agency or judicial authority or contained in any federal or state statute;

    are necessary or appropriate to facilitate the trading of limited partner interests or to comply with any rule, regulation, guideline or requirement of any securities exchange on which the limited partner interests are or will be listed or admitted to trading;

    are necessary or appropriate for any action taken by our general partner relating to splits or combinations of units under the provisions of our partnership agreement; or

    are required to effect the intent expressed in this prospectus or the intent of the provisions of our partnership agreement or are otherwise contemplated by our partnership agreement.

    Opinion of Counsel and Unitholder Approval

        For amendments of the type not requiring unitholder approval, our general partner will not be required to obtain an opinion of counsel to the effect that an amendment will not affect the limited liability of any limited partner under Delaware law. No other amendments to our partnership agreement will become effective without the approval of holders of at least 90% of the outstanding units voting as a single class unless we first obtain such an opinion.

        In addition to the above restrictions, any amendment that would have a material adverse effect on the rights or preferences of any type or class of partnership interests in relation to other classes of partnership interests will require the approval of at least a majority of the type or class of partnership interests so affected. Any amendment that would reduce the percentage of units required to take any action, other than to remove our general partner or call a meeting of unitholders, must be approved by the affirmative vote of limited partners whose aggregate outstanding units constitute not less than the percentage sought to be reduced. Any amendment that would increase the percentage of units required to remove our general partner must be approved by the affirmative vote of limited partners whose aggregate outstanding units constitute not less than 90% of outstanding units. Any amendment that would increase the percentage of units required to call a meeting of unitholders must be approved by the affirmative vote of limited partners whose aggregate outstanding units constitute at least a majority of the outstanding units.

Merger, Consolidation, Conversion, Sale or Other Disposition of Assets

        A merger, consolidation or conversion of us requires the prior consent of our general partner. However, our general partner will have no duty or obligation to consent to any merger, consolidation or conversion and may decline to do so free of any duty or obligation whatsoever to us or the limited partners, including any duty to act in the best interest of us or the limited partners, other than the implied contractual covenant of good faith and fair dealing.

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        In addition, the partnership agreement generally prohibits our general partner without the prior approval of the holders of a unit majority, from causing us to, among other things, sell, exchange or otherwise dispose of all or substantially all of our assets in a single transaction or a series of related transactions. Our general partner may, however, mortgage, pledge, hypothecate or grant a security interest in all or substantially all of our assets without that approval. Our general partner may also sell any or all of our assets under a foreclosure or other realization upon those encumbrances without that approval. Finally, our general partner may consummate any merger with another limited liability entity without the prior approval of our unitholders if we are the surviving entity in the transaction, our general partner has received an opinion of counsel regarding limited liability and tax matters, the transaction would not result in an amendment to the partnership agreement requiring unitholder approval, each of our units will be an identical unit of our partnership following the transaction, and the partnership interests to be issued by us in such merger do not exceed 20% of our outstanding partnership interests immediately prior to the transaction.

        If the conditions specified in the partnership agreement are satisfied, our general partner may convert us or any of our subsidiaries into a new limited liability entity or merge us or any of our subsidiaries into, or convey all of our assets to, a newly formed entity if the sole purpose of that conversion, merger or conveyance is to effect a mere change in our legal form into another limited liability entity, our general partner has received an opinion of counsel regarding limited liability and tax matters, and the general partner determines that the governing instruments of the new entity provide the limited partners and the general partner with the same rights and obligations as contained in the partnership agreement. The unitholders are not entitled to dissenters' rights of appraisal under the partnership agreement or applicable Delaware law in the event of a conversion, merger or consolidation, a sale of substantially all of our assets or any other similar transaction or event.

Dissolution

        We will continue as a limited partnership until dissolved under our partnership agreement. We will dissolve upon:

    the election of our general partner to dissolve us, if approved by the holders of units representing a unit majority;

    there being no limited partners, unless we are continued without dissolution in accordance with applicable Delaware law;

    the entry of a decree of judicial dissolution of our partnership; or

    the withdrawal or removal of our general partner or any other event that results in its ceasing to be our general partner, other than by reason of a transfer of its general partner interest in accordance with our partnership agreement or withdrawal or removal followed by approval and admission of a successor.

        Upon a dissolution under the last clause above, the holders of a unit majority may also elect, within specific time limitations, to continue our business on the same terms and conditions described in our partnership agreement by appointing as a successor general partner an entity approved by the holders of units representing a unit majority, subject to our receipt of an opinion of counsel to the effect that:

    the action would not result in the loss of limited liability of any limited partner; and

    neither our partnership nor any of our subsidiaries would be treated as an association taxable as a corporation or otherwise be taxable as an entity for federal income tax purposes upon the exercise of that right to continue.

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Liquidation and Distribution of Proceeds

        Upon our dissolution, unless we are continued as a new limited partnership, the liquidator authorized to wind up our affairs will, acting with all of the powers of our general partner that are necessary or appropriate, liquidate our assets and apply the proceeds of the liquidation as described in "Cash Distribution Policy—Distributions of Cash Upon Liquidation." The liquidator may defer liquidation or distribution of our assets for a reasonable period of time or distribute assets to partners in kind if it determines that a sale would be impractical or would cause undue loss to our partners.

Withdrawal or Removal of the General Partner

        Except as described below, our general partner has agreed not to withdraw voluntarily as our general partner prior to June 30, 2022 without obtaining the approval of the holders of at least a majority of the outstanding common units, excluding common units held by the general partner and its affiliates, and furnishing an opinion of counsel regarding limited liability and tax matters. On or after June 30, 2022, our general partner may withdraw as general partner without first obtaining approval of any unitholder by giving 90 days' written notice, and that withdrawal will not constitute a violation of our partnership agreement. Notwithstanding the information above, our general partner may withdraw without unitholder approval upon 90 days' notice to the limited partners if at least 50.0% of the outstanding units are held or controlled by one person and its affiliates other than the general partner and its affiliates. In addition, the partnership agreement permits our general partner in some instances to sell or otherwise transfer all of its general partner interest in us without the approval of the unitholders. Please read "—Transfer of General Partner Units" and "—Transfer of Incentive Distribution Rights."

        Upon voluntary withdrawal of our general partner by giving written notice to the other partners, the holders of a unit majority may select a successor to that withdrawing general partner. If a successor is not elected, or is elected but an opinion of counsel regarding limited liability and tax matters cannot be obtained, we will be dissolved, wound up and liquidated, unless within a specified period after that withdrawal, the holders of a unit majority agree to continue our business by appointing a successor general partner. Please read "—Dissolution."

        Our general partner may not be removed unless that removal is approved by the vote of the holders of not less than 662/3% of the outstanding units, voting together as a single class, including units held by our general partner and its affiliates, and we receive an opinion of counsel regarding limited liability and tax matters. Any removal of our general partner is also subject to the approval of a successor general partner by the vote of the holders of a majority of the outstanding common units voting as a separate class. The ownership of more than 331/3% of the outstanding units by our general partner and its affiliates would give them the practical ability to prevent our general partner's removal. As of the date of this prospectus, EQGP owns an approximate 30.2% limited partner interest in us.

        Our partnership agreement also provides that if our general partner is removed as our general partner under circumstances where cause does not exist and units held by the general partner and its affiliates are not voted in favor of that removal, our general partner will have the right to convert its general partner interest and its incentive distribution rights into common units or to receive cash in exchange for those interests based on the fair market value of those interests as of the effective date of its removal.

        In the event of removal of a general partner under circumstances where cause exists or withdrawal of a general partner where that withdrawal violates our partnership agreement, a successor general partner will have the option to purchase the general partner interest and incentive distribution rights of the departing general partner for a cash payment equal to the fair market value of those interests. Under all other circumstances where a general partner withdraws or is removed by the limited partners, the departing general partner will have the option to require the successor general partner to purchase

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the general partner interest of the departing general partner and its incentive distribution rights for fair market value. In each case, this fair market value will be determined by agreement between the departing general partner and the successor general partner. If no agreement is reached, an independent investment banking firm or other independent expert selected by the departing general partner and the successor general partner will determine the fair market value. Or, if the departing general partner and the successor general partner cannot agree upon an expert, then an expert chosen by agreement of the experts selected by each of them will determine the fair market value.

        If the option described above is not exercised by either the departing general partner or the successor general partner, the departing general partner will become a limited partner and its general partner interest and its incentive distribution rights will automatically convert into common units pursuant to a valuation of those interests as determined by an investment banking firm or other independent expert selected in the manner described in the preceding paragraph.

        In addition, we will be required to reimburse the departing general partner for all amounts due the departing general partner, including, without limitation, all employee-related liabilities, including severance liabilities, incurred for the termination of any employees employed by the departing general partner or its affiliates for our benefit.

Transfer of General Partner Units

        Except for transfer by our general partner of all, but not less than all, of its general partner units to:

    an affiliate of our general partner (other than an individual); or

    another entity as part of the merger or consolidation of our general partner with or into such entity or the transfer by our general partner of all or substantially all of its assets to such entity,

our general partner may not transfer all or any of its general partner units to another person prior to June 30, 2022 without the approval of the holders of at least a majority of the outstanding common units, excluding common units held by our general partner and its affiliates. As a condition of this transfer, the transferee must assume, among other things, the rights and duties of our general partner, agree to be bound by the provisions of our partnership agreement, and furnish an opinion of counsel regarding limited liability and tax matters.

        On or after June 30, 2022, our general partner and its affiliates may at any time transfer units to one or more persons, without unitholder approval.

Transfer of Ownership Interests in the General Partner

        At any time, EQT and its affiliates may sell or transfer all or part of their membership interest in our general partner, or their membership interest in EQGP, as the sole member of our general partner, to an affiliate or third party without the approval of our unitholders.

Transfer of Incentive Distribution Rights

        At any time, our general partner may sell or transfer its incentive distribution rights to an affiliate or third party without the approval of our unitholders.

Change of Management Provisions

        Our partnership agreement contains specific provisions that are intended to discourage a person or group from attempting to remove EQT Midstream Services, LLC as our general partner or otherwise change our management. If any person or group other than our general partner and its affiliates acquires beneficial ownership of 20% or more of any class of units, that person or group loses voting

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rights on all of its units. This loss of voting rights does not apply to any person or group that acquires the units from our general partner or its affiliates and any transferees of that person or group who are notified by our general partner that they will not lose their voting rights or to any person or group who acquires the units with the prior approval of the board of directors of our general partner.

        Our partnership agreement also provides that if our general partner is removed as our general partner under circumstances where cause does not exist and units held by our general partner and its affiliates are not voted in favor of that removal, our general partner will have the right to convert its general partner units and its incentive distribution rights into common units or to receive cash in exchange for those interests based on the fair market value of those interests as of the effective date of its removal.

Limited Call Right

        If at any time our general partner and its affiliates own more than 80% of the then-issued and outstanding limited partner interests of any class, our general partner will have the right, which it may assign in whole or in part to any of its affiliates or to us, to acquire all, but not less than all, of the limited partner interests of such class held by unaffiliated persons as of a record date to be selected by our general partner, on at least 10 but not more than 60 days' notice. The purchase price in the event of this purchase is the greater of:

    the highest cash price paid by either of our general partner or any of its affiliates for any limited partner interests of the class purchased within the 90 days preceding the date on which our general partner first mails notice of its election to purchase those limited partner interests; and

    the current market price calculated in accordance with our partnership agreement as of the date three business days before the date the notice is mailed.

        As a result of our general partner's right to purchase outstanding limited partner interests, a holder of limited partner interests may have his limited partner interests purchased at a price that may be lower than market prices at various times prior to such purchase or lower than a unitholder may anticipate the market price to be in the future. The tax consequences to a unitholder of the exercise of this call right are the same as a sale by that unitholder of his common units in the market. Please read "Material Federal Income Tax Consequences—Disposition of Common Units."

Redemption of Ineligible Holders

        In order to avoid any material adverse effect on the maximum applicable rates that can be charged to customers by our subsidiaries on assets that are subject to rate regulation by the Federal Energy Regulatory Commission (FERC) or an analogous regulatory body, our general partner, acting on our behalf, may at any time require any or all unitholders to certify that such unitholder or its respective transferee is an entity:

    whose, or whose owners', U.S. federal income tax status (or lack of proof of U.S. federal income tax status) does not have or is not reasonably likely to have, as determined by our general partner, a material adverse effect on the rates that can be charged to customers with respect to assets that are subject to regulation by the FERC; or

    as to whom our general partner cannot make the determination above, if our general partner determines that it is in our best interest to permit such individual or entity to own interests in us.

        Furthermore, in order to avoid a substantial risk of cancellation or forfeiture of any property in which we have an interest as the result of any federal, state or local law or regulation concerning the nationality, citizenship or other related status of any unitholder, our general partner may at any time

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request unitholders to certify as to, or provide other information with respect to, their nationality, citizenship or other related status.

        The certifications as to taxpayer status and nationality, citizenship or other related status can be changed in any manner our general partner determines is necessary or appropriate to implement its original purpose.

        If a unitholder fails to furnish the certification or other requested information within 30 days or if our general partner determines, with the advice of counsel, upon review of such certification or other information that a unitholder does not meet the status set forth in the certification, we will have the right to redeem all of the units held by such unitholder at the market price as of the date three days before the date the notice of redemption is mailed.

        The purchase price will be paid in cash or by delivery of a promissory note, as determined by our general partner. Any such promissory note will bear interest at the rate of 5.0% annually and be payable in three equal annual installments of principal and accrued interest, commencing one year after the redemption date. Further, the units will not be entitled to any allocations of income or loss, distributions or voting rights while held by such unitholder.

Meetings; Voting

        Except as described below regarding a person or group owning 20% or more of any class of units then outstanding, record holders of units on the record date will be entitled to notice of, and to vote at, meetings of our limited partners and to act upon matters for which approvals may be solicited.

        Our general partner does not anticipate that any meeting of unitholders will be called in the foreseeable future. Any action that is required or permitted to be taken by the unitholders may be taken either at a meeting of the unitholders or, if authorized by our general partner, without a meeting if consents in writing describing the action so taken are signed by holders of the number of units that would be necessary to authorize or take that action at a meeting where all limited partners were present and voted. Meetings of the unitholders may be called by our general partner or by unitholders owning at least 20% of the outstanding units of the class for which a meeting is proposed. Unitholders may vote either in person or by proxy at meetings. The holders of a majority of the outstanding units of the class or classes for which a meeting has been called represented in person or by proxy will constitute a quorum unless any action by the unitholders requires approval by holders of a greater percentage of the units, in which case the quorum will be the greater percentage.

        Each record holder of a unit has a vote according to his percentage interest in us, although additional limited partner interests having special voting rights could be issued. Please read "—Issuance of Additional Partnership Interests." However, if at any time any person or group, other than our general partner and its affiliates, a direct transferee of our general partner and its affiliates or a transferee of such direct transferee who is notified by our general partner that it will not lose its voting rights, acquires, in the aggregate, beneficial ownership of 20% or more of any class of units then outstanding, that person or group will lose voting rights on all of its units and the units may not be voted on any matter and will not be considered to be outstanding when sending notices of a meeting of unitholders, calculating required votes, determining the presence of a quorum or for other similar purposes. Common units held in nominee or street name account will be voted by the broker or other nominee in accordance with the instruction of the beneficial owner unless the arrangement between the beneficial owner and his nominee provides otherwise.

        Any notice, demand, request, report or proxy material required or permitted to be given or made to record holders of common units under our partnership agreement will be delivered to the record holder by us or by the transfer agent.

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Status as Limited Partner

        By transfer of common units in accordance with our partnership agreement, each transferee of common units shall be admitted as a limited partner with respect to the common units transferred when such transfer and admission is reflected in our register. Except as described under "—Limited Liability," the common units will be fully paid, and unitholders will not be required to make additional contributions.

Indemnification

        Under our partnership agreement, in most circumstances, we will indemnify the following persons, to the fullest extent permitted by law, from and against all losses, claims, damages or similar events:

    our general partner;

    any departing general partner;

    any person who is or was an affiliate of a general partner or any departing general partner;

    any person who is or was a director, officer, managing member, manager, general partner, fiduciary or trustee of our subsidiaries, us or any entity set forth in the preceding three bullet points;

    any person who is or was serving as director, officer, managing member, manager, general partner, fiduciary or trustee of another person owing a fiduciary duty to us or any of our subsidiaries at the request of our general partner or any departing general partner or any of their affiliates; and

    any other person designated by our general partner.

        Any indemnification under these provisions will only be out of our assets. Unless it otherwise agrees, our general partner will not be personally liable for, or have any obligation to contribute or lend funds or assets to us to enable us to effectuate, indemnification. Our general partner has purchased insurance against liabilities asserted against and expenses incurred by persons for our activities, regardless of whether we would have the power to indemnify the person against such liabilities under our partnership agreement.

Reimbursement of Expenses

        Our partnership agreement requires us to reimburse our general partner for all direct and indirect expenses it incurs or payments it makes on our behalf and all other expenses allocable to us or otherwise incurred by our general partner in connection with operating our business. These expenses include salary, bonus, incentive compensation and other amounts paid to persons who perform services for us or on our behalf and expenses allocated to our general partner by its affiliates. The general partner is entitled to determine in good faith the expenses that are allocable to us.

Books and Reports

        Our general partner is required to keep appropriate books of our business at our principal offices. The books will be maintained for financial reporting purposes on an accrual basis. For tax and fiscal reporting purposes, our fiscal year is the calendar year.

        We will mail or make available to record holders of common units, within 105 days after the close of each fiscal year, an annual report containing audited financial statements and a report on those financial statements by our independent public accountants. Except for our fourth quarter, we will also mail or make available summary financial information within 50 days after the close of each quarter.

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        We will furnish each record holder of a unit with information reasonably required for tax reporting purposes within 90 days after the close of each calendar year. This information is expected to be furnished in summary form so that some complex calculations normally required of partners can be avoided. Our ability to furnish this summary information to unitholders will depend on the cooperation of such unitholders in supplying us with specific information. Every unitholder will receive information to assist him in determining his federal and state tax liability and filing his federal and state income tax returns, regardless of whether he supplies us with information.

Right to Inspect Our Books and Records

        Our partnership agreement provides that a limited partner can, for a purpose reasonably related to his interest as a limited partner, upon reasonable written demand stating the purpose of such demand and at his own expense, have furnished to him:

    a current list of the name and last known address of each record holder;

    copies of our partnership agreement and our certificate of limited partnership and all amendments thereto; and

    certain information regarding the status of our business and financial condition.

        Our general partner may, and intends to, keep confidential from the limited partners, trade secrets or other information the disclosure of which our general partner determines is not in our best interests or that we are required by law or by agreements with third parties to keep confidential. Our partnership agreement limits the right to information that a limited partner would otherwise have under Delaware law.

Registration Rights

        Under our partnership agreement, we have agreed to register for resale under the Securities Act of 1933, as amended (Securities Act), and applicable state securities laws any common units or other partnership interests proposed to be sold by our general partner or any of its affiliates or their assignees if an exemption from the registration requirements is not otherwise available. These registration rights continue for two years following any withdrawal or removal of EQT Midstream Services, LLC as general partner. We are obligated to pay all expenses incidental to the registration, excluding underwriting discounts and commissions.

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CASH DISTRIBUTION POLICY

        References in this "Cash Distribution Policy" to "we," "us" and "our" mean EQT Midstream Partners, LP.

Distributions of Available Cash

    General

        Our partnership agreement requires that, within 45 days after the end of each quarter, we distribute all of our available cash to unitholders of record on the applicable record date.

    Definition of Available Cash

        Available cash generally means, for any quarter, all cash and cash equivalents on hand at the end of that quarter:

    less, the amount of cash reserves established by our general partner to:

    provide for the proper conduct of our business (including reserves for future capital expenditures, anticipated future debt service requirements and refunds of collected rates reasonably likely to be refunded as a result of a settlement or hearing related to FERC rate proceedings or rate proceedings under applicable law subsequent to that quarter);

    comply with applicable law, any of our debt instruments or other agreements; or

    provide funds for distributions to our unitholders and to our general partner for any one or more of the next four quarters (provided that our general partner may not establish cash reserves for distributions if the effect of the establishment of such reserves will prevent us from distributing the minimum quarterly distribution on all common units);

    plus, if our general partner so determines, all or any portion of the cash on hand on the date of determination of available cash for the quarter resulting from working capital borrowings made subsequent to the end of such quarter.

        The purpose and effect of the last bullet point above is to allow our general partner, if it so decides, to use cash from working capital borrowings made after the end of the quarter but on or before the date of determination of available cash for that quarter to pay distributions to unitholders. Under our partnership agreement, working capital borrowings are generally borrowings that are made under a credit facility, commercial paper facility or similar financing arrangement, and in all cases are used solely for working capital purposes or to pay distributions to partners, and with the intent of the borrower to repay such borrowings within 12 months with funds other than from additional working capital borrowings.

    Minimum Quarterly Distribution

        The minimum quarterly distribution, as defined in our partnership agreement, is $0.3500 per unit, or $1.40 on an annualized basis. Our most recent quarterly distribution was $0.61 per unit, or $2.44 per unit on an annualized basis. There is no guarantee that we will maintain our current level of distributions or pay the minimum quarterly distribution on our units in any quarter. Even if our cash distribution policy is not modified or revoked, the amount of distributions paid under our policy and the decision to make any distribution is determined by our general partner, taking into consideration the terms of our partnership agreement.

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    General Partner Interest and Incentive Distribution Rights

        As of the date of this prospectus, our general partner is entitled to a percentage of all quarterly distributions that we make equal to its 2.0% general partner interest in us. This general partner interest is currently represented by 1,443,015 general partner units. Our general partner has the right, but not the obligation, to contribute a proportionate amount of capital to us to maintain its current general partner interest. Our general partner's 2.0% interest in these distributions will be reduced if we issue additional units in the future and our general partner does not contribute a proportionate amount of capital to us to maintain its 2.0% general partner interest.

        Our general partner also currently holds incentive distribution rights that entitle it to receive increasing percentages, up to a maximum of 48.0%, of the cash we distribute from operating surplus (as defined below) in excess of $0.4025 per unit per quarter. The maximum distribution of 48.0% does not include any distributions that our general partner or its affiliates may receive on common or general partner units that they own.

Operating Surplus and Capital Surplus

    General

        All cash distributed to unitholders will be characterized as either being paid from "operating surplus" or "capital surplus." We treat distributions of available cash from operating surplus differently than distributions of available cash from capital surplus.

    Operating Surplus

        Operating surplus is defined in our partnership agreement as:

    $30 million (as described below); plus

    all of our cash receipts, excluding cash from interim capital transactions (as defined below), provided that cash receipts from the termination of a commodity hedge or interest rate hedge prior to its specified termination date shall be included in operating surplus in equal quarterly installments over the remaining scheduled life of such commodity hedge or interest rate hedge; plus

    working capital borrowings made after the end of a quarter but before the date of determination of operating surplus for that quarter; plus

    cash distributions (including incremental distributions on incentive distribution rights) paid in respect of equity issued, other than equity issued in our initial public offering, to finance all or a portion of expansion capital expenditures in respect of the period from the date that we enter into a binding obligation to commence the construction, development, replacement, improvement or expansion of a capital asset and ending on the earlier to occur of the date the capital asset commences commercial service and the date that it is abandoned or disposed of; plus

    cash distributions (including incremental distributions on incentive distribution rights) paid in respect of equity issued, other than equity issued in our initial public offering, to finance the expansion capital expenditures referred to in the prior bullet; less

    all of our operating expenditures (as defined below) after the closing of our initial public offering; less

    the amount of cash reserves established by our general partner to provide funds for future operating expenditures; less

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    all working capital borrowings not repaid within 12 months after having been incurred, or repaid within such 12-month period with the proceeds of additional working capital borrowings; less

    any cash loss realized on disposition of an investment capital expenditure.

        As described above, operating surplus does not reflect actual cash on hand that is available for distribution to our unitholders and is not limited to cash generated by operations. For example, it includes a provision that will enable us, if we choose, to distribute as operating surplus up to $30 million of cash we receive in the future from non-operating sources such as asset sales, issuances of securities and long-term borrowings that would otherwise be distributed as capital surplus. In addition, the effect of including, as described above, certain cash distributions on equity interests in operating surplus will be to increase operating surplus by the amount of any such cash distributions. As a result, we may also distribute as operating surplus up to the amount of any such cash that we receive from non-operating sources.

        The proceeds of working capital borrowings increase operating surplus and repayments of working capital borrowings are generally operating expenditures (as described below) and thus reduce operating surplus when repayments are made. However, if working capital borrowings, which increase operating surplus, are not repaid during the 12-month period following the borrowing, they will be deemed repaid at the end of such period, thus decreasing operating surplus at such time. When such working capital borrowings are in fact repaid, they will not be treated as a further reduction in operating surplus because operating surplus will have been previously reduced by the deemed repayment.

        We define interim capital transactions as (i) borrowings, refinancings or refundings of indebtedness (other than working capital borrowings and items purchased on open account or for a deferred purchase price in the ordinary course of business) and sales of debt securities, (ii) sales of equity securities, and (iii) sales or other dispositions of assets, other than sales or other dispositions of inventory, accounts receivable and other assets in the ordinary course of business and sales or other dispositions of assets as part of normal asset retirements or replacements.

        We define operating expenditures as all of our cash expenditures, including, but not limited to, taxes, reimbursements of expenses of our general partner and its affiliates, director and employee compensation, debt service payments, payments made in the ordinary course of business under interest rate hedge contracts and commodity hedge contracts (provided that payments made in connection with the termination of any interest rate hedge contract or commodity hedge contract prior to the expiration of its settlement or termination date specified therein will be included in operating expenditures in equal quarterly installments over the remaining scheduled life of such interest rate hedge contract or commodity hedge contract and amounts paid in connection with the initial purchase of a rate hedge contract or a commodity hedge contract will be amortized at the life of such rate hedge contract or commodity hedge contract), maintenance capital expenditures (as discussed in further detail below), and repayment of working capital borrowings; provided, however, that operating expenditures will not include:

    repayments of working capital borrowings where such borrowings have previously been deemed to have been repaid (as described above);

    payments (including prepayments and prepayment penalties) of principal of and premium on indebtedness other than working capital borrowings;

    expansion capital expenditures;

    investment capital expenditures;

    payment of transaction expenses (including taxes) relating to interim capital transactions;

    distributions to our partners; or

    repurchases of partnership interests (excluding repurchases we make to satisfy obligations under employee benefit plans).

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    Capital Surplus

        Capital surplus is defined in our partnership agreement as any distribution of available cash in excess of our cumulative operating surplus. Accordingly, except as described above, capital surplus would generally be generated by:

    borrowings other than working capital borrowings;

    sales of our equity and debt securities; and

    sales or other dispositions of assets, other than inventory, accounts receivable and other assets sold in the ordinary course of business or as part of ordinary course retirement or replacement of assets.

    Characterization of Cash Distributions

        Our partnership agreement requires that we treat all available cash distributed as coming from operating surplus until the sum of all available cash distributed since the closing of our initial public offering equals the operating surplus from the closing of the initial public offering through the end of the quarter immediately preceding that distribution. Our partnership agreement requires that we treat any amount distributed in excess of operating surplus, regardless of its source, as capital surplus. We do not anticipate that we will make any distributions from capital surplus.

Capital Expenditures

        Expansion capital expenditures are cash expenditures incurred for acquisitions or capital improvements that we expect will increase our operating income or operating capacity over the long term. Examples of expansion capital expenditures include the acquisition of equipment and the construction, development or acquisition of additional transmission, storage or gathering capacity to the extent such capital expenditures are expected to expand our operating capacity or our operating income. Expansion capital expenditures include interest payments (and related fees) on debt incurred to finance all or a portion of expansion capital expenditures in respect of the period from the date that we enter into a binding obligation to commence the construction, development, replacement, improvement or expansion of a capital asset and ending on the earlier to occur of the date that such capital improvement commences commercial service and the date that such capital improvement is abandoned or disposed of.

        Maintenance capital expenditures are cash expenditures (including expenditures for the construction or development of new capital assets or the replacement, improvement or expansion of existing capital assets) made to maintain, over the long term, our operating capacity or operating income. Examples of maintenance capital expenditures are expenditures to repair, refurbish and replace pipelines, to connect new wells to maintain throughput, to maintain equipment reliability, integrity and safety and to address environmental laws and regulations.

        Investment capital expenditures are those capital expenditures that are neither maintenance capital expenditures nor expansion capital expenditures. Investment capital expenditures largely will consist of capital expenditures made for investment purposes. Examples of investment capital expenditures include traditional capital expenditures for investment purposes, such as purchases of securities, as well as other capital expenditures that might be made in lieu of such traditional investment capital expenditures, such as the acquisition of a capital asset for investment purposes or development of facilities that are in excess of the maintenance of our existing operating capacity or operating income, but that are not expected to expand our operating capacity or operating income over the long term.

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        Capital expenditures that are made in part for maintenance capital purposes, investment capital purposes and/or expansion capital purposes will be allocated as maintenance capital expenditures, investment capital expenditures or expansion capital expenditures by our general partner.

Adjusted Operating Surplus

        Adjusted operating surplus is intended to reflect the cash generated from operations during a particular period and therefore excludes net drawdowns of reserves of cash established in prior periods. Adjusted operating surplus for a period consists of:

    operating surplus generated with respect to that period (excluding any amounts attributable to the item described in the first bullet point under the caption "—Operating Surplus and Capital Surplus—Operating Surplus" above); less

    any net increase in working capital borrowings with respect to that period; less

    the amount of any payments by EQT pursuant to an omnibus agreement for certain unrecoverable pipeline safety tracker costs; less

    any net decrease in cash reserves for operating expenditures with respect to that period not relating to an operating expenditure made with respect to that period; plus

    any net decrease in working capital borrowings with respect to that period; plus

    any net decrease made in subsequent periods to cash reserves for operating expenditures initially established with respect to that period to the extent such decrease results in a reduction in adjusted operating surplus in subsequent periods; plus

    any net increase in cash reserves for operating expenditures with respect to that period required by any debt instrument for the repayment of principal, interest or premium.

Distributions of Available Cash from Operating Surplus

        Our common units have the right to receive distributions of available cash from operating surplus each quarter in an amount equal to $0.3500 per common unit (the minimum quarterly distribution), and are not entitled to any arrearages in the payment of the minimum quarterly distribution on the common units from prior quarters.

        We will make distributions of available cash from operating surplus for any quarter in the following manner:

    first, 98.0% to all unitholders, pro rata, and 2.0% to our general partner, until we distribute for each outstanding unit an amount equal to the minimum quarterly distribution for that quarter; and

    thereafter, in the manner described in "—General Partner Interest and Incentive Distribution Rights" below.

        The preceding discussion is based on the assumptions that our general partner maintains its 2.0% general partner interest and that we do not issue additional classes of equity securities.

General Partner Interest and Incentive Distribution Rights

        As of the date of this prospectus, our general partner is entitled to a percentage of all quarterly distributions equal to its 2.0% general partnership interest. Our general partner has the right, but not the obligation, to contribute a proportionate amount of capital to us in order to maintain its 2.0% general partner interest if we issue additional units. Our general partner's 2.0% interest, and the percentage of our cash distributions to which it is entitled from such 2.0% interest, will be

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proportionately reduced if we issue additional units in the future and our general partner does not contribute a proportionate amount of capital to us in order to maintain its 2.0% general partner interest. Our partnership agreement does not require that our general partner fund its capital contribution with cash. It may instead fund its capital contribution by the contribution to us of common units or other property.

        Incentive distribution rights represent the right to receive an increasing percentage (13.0%, 23.0% and 48.0%) of quarterly distributions of available cash from operating surplus after the minimum quarterly distribution and the target distribution levels have been achieved. The target distribution levels are based on the amounts of available cash from operating surplus distributed above the payments made under the minimum quarterly distribution, if any, and the related 2.0% distribution to our general partner. Our general partner currently holds the incentive distribution rights, but may transfer these rights separately from its general partner interest, subject to restrictions in our partnership agreement. The following discussion assumes that our general partner maintains its 2.0% general partner interest and that our general partner continues to own the incentive distribution rights.

        For any quarter that we have distributed available cash from operating surplus to the common unitholders in an amount equal to the minimum quarterly distribution, we will distribute any additional available cash from operating surplus for that quarter among the unitholders and our general partner in the following manner:

    first, 98.0% to all unitholders, pro rata, and 2.0% to our general partner, until each unitholder receives a total of $0.4025 per unit for that quarter (the "first target distribution");

    second, 85.0% to all unitholders, pro rata, and 15.0% to our general partner, until each unitholder receives a total of $0.4375 per unit for that quarter (the "second target distribution");

    third, 75.0% to all unitholders, pro rata, and 25.0% to our general partner, until each unitholder receives a total of $0.5250 per unit for that quarter (the "third target distribution"); and

    thereafter, 50.0% to all unitholders, pro rata, and 50.0% to our general partner.

Percentage Allocations of Available Cash from Operating Surplus

        The following table illustrates the percentage allocations of available cash from operating surplus between the unitholders and our general partner based on the specified target distribution levels. The amounts set forth under "Marginal Percentage Interest in Distributions" are the percentage interests of our general partner and the unitholders in any available cash from operating surplus we distribute up to and including the corresponding amount in the column "Total Quarterly Distribution Per Unit Target Amount." The percentage interests shown for our unitholders and our general partner for the minimum quarterly distribution are also applicable to quarterly distribution amounts that are less than the minimum quarterly distribution. The percentage interests set forth below for our general partner include its 2.0% general partner interest and assume that our general partner has contributed any

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additional capital necessary to maintain its 2.0% general partner interest and our general partner has not transferred its incentive distribution rights.

 
   
   
  Marginal Percentage
Interest in Distributions
 
 
  Total Quarterly
Distribution Per Unit
Target Amount
  Unitholders   General
Partner
 

Minimum Quarterly Distribution

        $ 0.3500     98.0 %   2.0 %

First Target Distribution

    above   $ 0.3500     98.0 %   2.0 %

    up to   $ 0.4025              

Second Target Distribution

    above   $ 0.4025     85.0 %   15.0 %

    up to   $ 0.4375              

Third Target Distribution

    above   $ 0.4375     75.0 %   25.0 %

    up to   $ 0.5250              

Thereafter

    above   $ 0.5250     50.0 %   50.0 %

General Partner's Right to Reset Incentive Distribution Levels

        Our general partner, as the current holder of our incentive distribution rights, has the right under our partnership agreement, subject to certain conditions, to elect to relinquish the right to receive incentive distribution payments based on the initial target distribution levels and to reset, at higher levels, the minimum quarterly distribution amount and target distribution levels upon which the incentive distribution payments to our general partner would be set. If our general partner transfers all or a portion of our incentive distribution rights in the future, then the holder or holders of a majority of our incentive distribution rights will be entitled to exercise this right. The following discussion assumes that our general partner holds all of the incentive distribution rights at the time that a reset election is made. Our general partner's right to reset the minimum quarterly distribution amount and the target distribution levels upon which the incentive distributions payable to our general partner are based may be exercised, subject to certain restrictions, without approval of our unitholders or the conflicts committee of our general partner's board of directors, at any time when there are no subordinated units outstanding, we have made cash distributions to the holders of the incentive distribution rights at the highest level of incentive distribution for each of the four consecutive fiscal quarters immediately preceding such time and the amount of each such distribution did not exceed adjusted operating surplus for such quarter, respectively. If our general partner and its affiliates are not the holders of a majority of the incentive distribution rights at the time an election is made to reset the minimum quarterly distribution amount and the target distribution levels, then the proposed reset will be subject to the prior written concurrence of the general partner that the conditions described above have been satisfied. The reset minimum quarterly distribution amount and target distribution levels will be higher than the minimum quarterly distribution amount and the target distribution levels prior to the reset such that our general partner will not receive any incentive distributions under the reset target distribution levels until cash distributions per unit following this event increase as described below. We anticipate that our general partner would exercise this reset right in order to facilitate acquisitions or internal growth projects that would otherwise not be sufficiently accretive to cash distributions per common unit, taking into account the existing levels of incentive distribution payments being made to our general partner.

        In connection with the resetting of the minimum quarterly distribution amount and the target distribution levels and the corresponding relinquishment by our general partner of incentive distribution payments based on the target distributions prior to the reset, our general partner will be entitled to receive a number of newly issued common units based on a predetermined formula described below that takes into account the "cash parity" value of the average cash distributions related to the incentive distribution rights received by our general partner for the two quarters immediately preceding the reset

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event as compared to the average cash distributions per common unit during that two-quarter period. In addition, our general partner will be issued the number of general partner units necessary to maintain our general partner's interest in us immediately prior to the reset election.

        The number of common units that our general partner would be entitled to receive from us in connection with a resetting of the minimum quarterly distribution amount and the target distribution levels then in effect would be equal to the quotient determined by dividing (x) the average aggregate amount of cash distributions received by our general partner in respect of its incentive distribution rights during the two consecutive fiscal quarters ended immediately prior to the date of such reset election by (y) the average of the aggregate amount of cash distributed per common unit during each of these two quarters.

        Following a reset election, the minimum quarterly distribution amount will be reset to an amount equal to the average cash distribution amount per common unit for the two fiscal quarters immediately preceding the reset election (which amount we refer to as the "reset minimum quarterly distribution") and the target distribution levels will be reset to be correspondingly higher such that we would distribute all of our available cash from operating surplus for each quarter thereafter as follows:

    first, 98.0% to all unitholders, pro rata, and 2.0% to our general partner, until each unitholder receives an amount equal to 115.0% of the reset minimum quarterly distribution for that quarter;

    second, 85.0% to all unitholders, pro rata, and 15.0% to our general partner, until each unitholder receives an amount per unit equal to 125.0% of the reset minimum quarterly distribution for the quarter;

    third, 75.0% to all unitholders, pro rata, and 25.0% to our general partner, until each unitholder receives an amount per unit equal to 150.0% of the reset minimum quarterly distribution for the quarter; and

    thereafter, 50.0% to all unitholders, pro rata, and 50.0% to our general partner.

        Our general partner will be entitled to cause the minimum quarterly distribution amount and the target distribution levels to be reset on more than one occasion, provided that it may not make a reset election except at a time when it has received incentive distributions for the immediately preceding four consecutive fiscal quarters based on the highest level of incentive distributions that it is entitled to receive under our partnership agreement.

Distributions from Capital Surplus

    How Distributions from Capital Surplus Will Be Made

        We will make distributions of available cash from capital surplus, if any, in the following manner:

    first, 98.0% to all unitholders, pro rata, and 2.0% to our general partner, until the minimum quarterly distribution is reduced to zero, as described below under "—Effect of a Distribution from Capital Surplus"; and

    thereafter, as if such distributions were from operating surplus.

        The preceding discussion is based on the assumptions that our general partner maintains its 2.0% general partner interest and that we do not issue additional classes of equity securities.

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    Effect of a Distribution from Capital Surplus

        Our partnership agreement treats a distribution of capital surplus as the repayment of the initial unit price, which is a return of capital. The initial unit price less any distributions of capital surplus per unit is referred to as the "unrecovered initial unit price." Each time a distribution of capital surplus is made, the minimum quarterly distribution and the target distribution levels will be reduced in the same proportion as the corresponding reduction in the unrecovered initial unit price.

        Once we distribute capital surplus on a unit in an amount equal to the initial unit price:

    the minimum quarterly distribution and the target distribution levels will be reduced to zero for subsequent quarters;

    all distributions of available cash will be treated as operating surplus; and

    50.0% of distributions of available cash will be to all unitholders, pro rata, 2.0% will be to our general partner, and 48.0% will be to the holder of our incentive distribution rights.

        Distributions of capital surplus will reduce the minimum quarterly distribution; however, any distribution of capital surplus before the unrecovered initial unit price is reduced to zero cannot be applied to the payment of the minimum quarterly distribution.

Adjustment to the Minimum Quarterly Distribution and Target Distribution Levels

        In addition to adjusting the minimum quarterly distribution and target distribution levels to reflect a distribution of capital surplus, if we combine our units into fewer units or subdivide our units into a greater number of units (but not if we issue additional common units for cash or property), we will proportionately adjust:

    the minimum quarterly distribution;

    target distribution levels;

    the unrecovered initial unit price; and

    the number of general partner units comprising the general partner interest.

        For example, in the event of a two-for-one split of the common units, the minimum quarterly distribution, the target distribution levels and the unrecovered initial unit price would each be reduced to 50.0% of their initial levels.

        In addition, if legislation is enacted or if existing law is modified or interpreted by the relevant governmental authority so that we become taxable as a corporation or otherwise subject to taxation as an entity for federal, state or local income tax purposes, we will reduce the minimum quarterly distribution and the target distribution levels for each quarter by multiplying each distribution level by a fraction, which is equal to (i) the available cash for that quarter divided by (ii) the sum of available cash for that quarter plus our general partner's estimate of our aggregate liability for the quarter for such income taxes payable by reason of such legislation or interpretation. To the extent that the actual tax liability differs from the estimated tax liability for any quarter, the difference may be accounted for in subsequent quarters.

Distribution of Cash Upon Liquidation

    General

        If we were to dissolve, we would sell our assets or otherwise dispose of our assets in a process called liquidation. We would first apply the proceeds of liquidation to the payment of our creditors in the order of priority provided in our partnership agreement and by law, and thereafter, distribute any

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remaining proceeds to the unitholders and our general partner, in accordance with their capital account balances, as adjusted to reflect any gain or loss upon the sale or other disposition of our assets in liquidation.

    Manner of Adjustment

        If we were to liquidate, we would allocate any gain to our general partner and each unitholder as follows:

    first, to our general partner to the extent of any negative balance in its capital account;

    second, 98.0% to all unitholders, pro rata, and 2.0% to our general partner, until the capital account for each unit is equal to the sum of: (1) the unrecovered initial unit price; and (2) the amount of the minimum quarterly distribution for the quarter during which our liquidation occurs;

    third, 98.0% to all unitholders, pro rata, and 2.0% to our general partner, until we allocate under this paragraph an amount per unit equal to: (1) the sum of the excess of the first target distribution per unit over the minimum quarterly distribution per unit for each quarter of our existence; less (2) the cumulative amount per unit of any distributions of available cash from operating surplus in excess of the minimum quarterly distribution per unit that we distributed 98.0% to the unitholders, pro rata, and 2.0% to our general partner, for each quarter of our existence;

    fourth, 85.0% to all unitholders, pro rata, and 15.0% to our general partner, until we allocate under this paragraph an amount per unit equal to: (1) the sum of the excess of the second target distribution per unit over the first target distribution per unit for each quarter of our existence; less (2) the cumulative amount per unit of any distributions of available cash from operating surplus in excess of the first target distribution per unit that we distributed 85.0% to the unitholders, pro rata, and 15.0% to our general partner for each quarter of our existence;

    fifth, 75.0% to all unitholders, pro rata, and 25.0% to our general partner, until we allocate under this paragraph an amount per unit equal to: (1) the sum of the excess of the third target distribution per unit over the second target distribution per unit for each quarter of our existence; less (2) the cumulative amount per unit of any distributions of available cash from operating surplus in excess of the second target distribution per unit that we distributed 75.0% to the unitholders, pro rata, and 25.0% to our general partner for each quarter of our existence;

    thereafter, 50.0% to all unitholders, pro rata, and 50.0% to our general partner.

        The percentages set forth above are based on the assumption that our general partner has not transferred its incentive distribution rights and that we do not issue additional classes of equity securities.

        If we were to liquidate, we would allocate any losses, after making allocations of loss to our general partner and the unitholders in a manner intended to offset in reverse order the allocations of gains set forth above, to our general partner and each unitholder as follows:

    first, 98.0% to the holders of common units in proportion to the positive balances in their capital accounts and 2.0% to our general partner, until the capital accounts of the common unitholders have been reduced to zero; and

    thereafter, 100.0% to our general partner.

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    Adjustments to Capital Accounts

        Our partnership agreement requires that we make adjustments to capital accounts upon the issuance of additional units. In this regard, our partnership agreement specifies that we allocate any unrealized and, for tax purposes, unrecognized gain resulting from the adjustments to the unitholders and the general partner in the same manner as we allocate gain upon liquidation. In the event that we make positive adjustments to the capital accounts upon the issuance of additional units, our partnership agreement requires that we generally allocate any later negative adjustments to the capital accounts resulting from the issuance of additional units or upon our liquidation in a manner which results, to the extent possible, in the partners' capital account balances equaling the amount which they would have been if no earlier positive adjustments to the capital accounts had been made. In contrast to the allocations of gain, and except as provided above, we generally will allocate any unrealized and unrecognized loss resulting from the adjustments to capital accounts upon the issuance of additional units to the unitholders and our general partner based on their respective percentage ownership of us. If we make negative adjustments to the capital accounts as a result of such loss, future positive adjustments resulting from the issuance of additional units will be allocated in a manner designed to reverse the prior negative adjustments, and special allocations will be made upon liquidation in a manner that results, to the extent possible, in our unitholders' capital account balances equaling the amounts they would have been if no earlier adjustments for loss had been made.

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MATERIAL INCOME TAX CONSIDERATIONS

        This section is a summary of the material tax considerations that may be relevant to prospective unitholders who are individual citizens or residents of the U.S. and, unless otherwise noted in the following discussion, is the opinion of Baker Botts L.L.P., counsel to our general partner and us, insofar as it relates to legal conclusions with respect to matters of U.S. federal income tax law. This section is based upon current provisions of the Internal Revenue Code of 1986, as amended (the Code), existing and proposed Treasury regulations promulgated under the Code (the Treasury Regulations) and current administrative rulings and court decisions, all of which are subject to change. Later changes in these authorities may cause the tax consequences to vary substantially from the consequences described below. Unless the context otherwise requires, references in this section to "us," "our" or "we" are references to EQT Midstream Partners, LP and our operating subsidiaries.

        The following discussion does not comment on all federal income tax matters affecting us or our unitholders. Moreover, the discussion focuses on unitholders who are individual citizens or residents of the U.S. and has only limited application to corporations, estates, trusts, partnerships and entities treated like partnerships for federal income tax purposes, nonresident aliens, U.S. expatriates and former citizens or long-term residents of the United States or other unitholders subject to specialized tax treatment, such as banks, insurance companies and other financial institutions, tax-exempt institutions, foreign persons (including, without limitation, controlled foreign corporations, passive foreign investment companies and non-U.S. persons eligible for the benefits of an applicable income tax treaty with the United States), IRAs, real estate investment trusts (REITs), employee benefit plans or mutual funds, dealers in securities or currencies, traders in securities, U.S. persons whose "functional currency" is not the U.S. dollar, persons holding their units as part of a "straddle," "hedge," "conversion transaction" or other risk reduction transaction, and persons deemed to sell their units under the constructive sale provisions of the Code. In addition, the discussion only comments to a limited extent on state, and does not comment on local or foreign, tax consequences. Accordingly, we encourage each prospective unitholder to consult, and depend on, his own tax advisor in analyzing the federal, state, local and foreign tax consequences particular to him of the ownership or disposition of common units.

        All statements as to matters of law and legal conclusions, but not as to factual matters, contained in this section, unless otherwise noted, are the opinion of Baker Botts L.L.P. and are based on the accuracy of the representations made by us.

        We are relying on opinions and advice of Baker Botts L.L.P. An opinion of counsel represents only counsel's best legal judgment and does not bind the Internal Revenue Service (IRS) or the courts. Accordingly, the opinions and statements made herein may not be sustained by a court if contested by the IRS. Any contest of this sort with the IRS may materially and adversely impact the market for our common units and the prices at which common units trade. In addition, the costs of any contest with the IRS, principally legal, accounting and related fees, will result in a reduction in cash available for distribution to our unitholders and our general partner and thus will be borne indirectly by our unitholders and our general partner. Furthermore, the tax treatment of us, or of an investment in us, may be significantly modified by future legislative or administrative changes or court decisions. Any modifications may or may not be retroactively applied.

        For the reasons described below, Baker Botts L.L.P. has not rendered an opinion with respect to the following specific federal income tax issues: (i) the treatment of a unitholder whose common units are loaned to a short seller to cover a short sale of common units (please read "—Tax Consequences of Unit Ownership—Treatment of Securities Loans"); (ii) whether our monthly convention for allocating taxable income and losses is permitted by existing Treasury Regulations (please read "—Disposition of Common Units—Allocations Between Transferors and Transferees"); and (iii) whether our method for

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depreciating Section 743 adjustments is sustainable in certain cases (please read "—Tax Consequences of Unit Ownership—Section 754 Election" and "—Uniformity of Units").

Partnership Status

        A partnership is not a taxable entity and incurs no federal income tax liability. Instead, each partner of a partnership is required to take into account his share of items of income, gain, loss and deduction of the partnership in computing his federal income tax liability, regardless of whether cash distributions are made to him by the partnership. Pursuant to Code Section 731, distributions by a partnership to a partner are generally not taxable to the partnership or the partner unless the amount of cash distributed to him is in excess of the partner's adjusted basis in his partnership interest.

        Section 7704 of the Code provides that publicly traded partnerships will, as a general rule, be taxed as corporations. However, an exception, referred to as the "Qualifying Income Exception," exists with respect to publicly traded partnerships of which 90.0% or more of the gross income for every taxable year consists of "qualifying income." Qualifying income includes income and gains derived from the transportation, storage, processing and marketing of crude oil, natural gas and other products thereof. Other types of qualifying income include interest (other than from a financial business), dividends, gains from the sale of real property and gains from the sale or other disposition of capital assets held for the production of income that otherwise constitutes qualifying income. We estimate that less than 5% of our current gross income is not qualifying income; however, this estimate could change from time to time. Based upon and subject to this estimate, the factual representations made by us and our general partner and a review of the applicable legal authorities, Baker Botts L.L.P. is of the opinion that at least 90.0% of our current gross income constitutes qualifying income. The portion of our income that is qualifying income may change from time to time.

        It is the opinion of Baker Botts L.L.P. that, based upon the Code, its regulations, published revenue rulings and court decisions and the representations described below that:

    We will be classified as a partnership for federal income tax purposes; and

    Each of our operating subsidiaries, other than EQT Midstream Finance Corporation, will be disregarded as an entity separate from us or will be treated as a partnership for federal income tax purposes.

        In rendering its opinion, Baker Botts L.L.P. has relied on factual representations made by us and our general partner. The representations made by us and our general partner upon which Baker Botts L.L.P. has relied include, without limitation:

    Neither we nor any of the operating subsidiaries, other than EQT Midstream Finance Corporation, is organized as, has elected to be treated as or will elect to be treated as a corporation; and

    For every taxable year, more than 90.0% of our gross income has been and will be income of the type that Baker Botts L.L.P. has opined or will opine is "qualifying income" within the meaning of Section 7704(d) of the Code.

        We believe that these representations have been true in the past and expect that these representations will continue to be true in the future.

        We are a publicly traded partnership. The present federal income tax treatment of publicly traded partnerships, or an investment in the common units of publicly traded partnership, may be modified by administrative, legislative or judicial interpretation at any time. For example, from time to time, members of the U.S. Congress propose and consider substantive changes to the existing federal income tax laws that affect publicly traded partnerships, such as proposals eliminating the qualifying income exception upon which we rely for our treatment as a partnership for U.S. federal income tax purposes.

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Additionally, on May 6, 2015, the IRS and the U.S. Department of the Treasury published proposed regulations that provide industry-specific guidance regarding whether income earned from certain activities will constitute qualifying income. We are unable to predict whether any of these changes or any other proposals will ultimately be enacted, or whether proposed regulations, once issued in final form, will materially change interpretations of the current law, but it is possible that a change in law could affect us and may, if enacted, be applied retroactively. Any such changes could affect our ability to meet the Qualifying Income Exception and could negatively impact the value of an investment in our common units.

        If we fail to meet the Qualifying Income Exception, other than a failure that is determined by the IRS to be inadvertent and that is cured within a reasonable time after discovery (in which case the IRS may also require us to make adjustments with respect to our unitholders or pay other amounts), we will be treated as if we had transferred all of our assets, subject to liabilities, to a newly formed corporation, on the first day of the year in which we fail to meet the Qualifying Income Exception, in return for stock in that corporation, and then distributed that stock to the unitholders in liquidation of their interests in us. This deemed contribution and liquidation should be tax-free to unitholders and us so long as we, at that time, do not have liabilities in excess of the tax basis of our assets. Thereafter, we would be treated as a corporation for federal income tax purposes.

        If we were taxed as a corporation for federal income tax purposes in any taxable year, either as a result of a failure to meet the Qualifying Income Exception or otherwise, our items of income, gain, loss and deduction would be reflected only on our tax return rather than being passed through to our unitholders, and our net income would be taxed to us at corporate rates. In addition, pursuant to Code Section 301, any distribution made to a unitholder would be treated as taxable dividend income, to the extent of our current and accumulated earnings and profits, or, in the absence of earnings and profits, a nontaxable return of capital, to the extent of the unitholder's tax basis in his common units, or taxable capital gain, after the unitholder's tax basis in his common units is reduced to zero. Accordingly, taxation as a corporation would result in a material reduction in a unitholder's cash flow and after-tax return and thus would likely result in a substantial reduction of the value of the units.

        The discussion below is based on Baker Botts L.L.P.'s opinion that we will be classified as a partnership for federal income tax purposes.

Limited Partner Status

        Unitholders who are admitted as limited partners of EQT Midstream Partners, LP will be treated as partners of EQT Midstream Partners, LP for federal income tax purposes. Also, unitholders whose common units are held in street name or by a nominee and who have the right to direct the nominee in the exercise of all substantive rights attendant to the ownership of their common units will be treated as partners of EQT Midstream Partners, LP for federal income tax purposes.

        A beneficial owner of common units whose units have been transferred to a short seller to complete a short sale would appear to lose his status as a partner with respect to those units for federal income tax purposes. Please read "—Tax Consequences of Unit Ownership—Treatment of Securities Loans."

        Income, gains, deductions or losses would not appear to be reportable by a unitholder who is not a partner for federal income tax purposes, and any cash distributions received by a unitholder who is not a partner for federal income tax purposes would therefore be fully taxable as ordinary income. These holders are urged to consult their own tax advisors with respect to the tax consequences of holding common units in EQT Midstream Partners, LP. The references to "unitholders" in the discussion that follows are to persons who are treated as partners in EQT Midstream Partners, LP for federal income tax purposes.

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Tax Consequences of Unit Ownership

        Flow-Through of Taxable Income.    Subject to the discussion below under "—Entity-Level Collections," we will not pay any federal income tax. Instead, each unitholder will be required to report on his income tax return his share of our income, gains, losses and deductions without regard to whether we make cash distributions to him. Consequently, we may allocate income to a unitholder even if he has not received a cash distribution. The income we allocate to common unitholders will generally be taxable as ordinary income. Each unitholder will be required to include in income his allocable share of our income, gains, losses and deductions for our taxable year ending with or within his taxable year. Our taxable year ends on December 31.

        Treatment of Distributions.    Pursuant to Code Section 731, distributions by us to a unitholder generally will not be taxable to the unitholder for federal income tax purposes, except to the extent the amount of any such cash distribution exceeds his tax basis in his common units immediately before the distribution. Cash distributions made by us to a unitholder in an amount in excess of a unitholder's tax basis generally will be considered to be gain from the sale or exchange of our common units, taxable in accordance with the rules described under "—Disposition of Common Units" below. Any reduction in a unitholder's share of our liabilities for which no partner, including the general partner, bears the economic risk of loss, known as "nonrecourse liabilities," will be treated as a distribution by us of cash to that unitholder. To the extent our distributions cause a unitholder's "at-risk" amount to be less than zero at the end of any taxable year, Section 465 of the Code requires the recapture of any losses deducted in previous years. Please read "—Limitations on Deductibility of Losses."

        A decrease in a unitholder's percentage interest in us because of our issuance of additional common units will decrease his share of our nonrecourse liabilities under Section 752 of the Code, and thus will result in a corresponding deemed distribution of cash. This deemed distribution may constitute a non-pro rata distribution. A non-pro rata distribution of money or property may result in ordinary income to a unitholder, regardless of his tax basis in his common units, if the distribution reduces the unitholder's share of our "unrealized receivables," including depreciation recapture, depletion recapture and/or substantially appreciated "inventory items," each as defined in the Code, and collectively, "Section 751 Assets." To that extent, the unitholder will be treated as having been distributed his proportionate share of the Section 751 Assets and then having exchanged those assets with us in return for the non-pro rata portion of the actual distribution made to him. This latter deemed exchange will generally result in the unitholder's realization of ordinary income, which will equal the excess of (i) the non-pro rata portion of that distribution over (ii) the unitholder's tax basis for the share of Section 751 Assets deemed relinquished in the exchange.

        Basis of Common Units.    A unitholder's initial tax basis for his common units will be determined under Sections 722, 742 and 752 of the Code and will generally equal the amount he paid for the common units plus his share of our nonrecourse liabilities. That basis will be increased under Section 705 of the Code by his share of our income and by any increases in his share of our nonrecourse liabilities and decreased, but not below zero, by distributions from us, by the unitholder's share of our losses, by any decreases in his share of our nonrecourse liabilities and by his share of our expenditures that are not deductible in computing taxable income and are not required to be capitalized. A unitholder will have no share of our debt that is recourse to our general partner to the extent of the general partner's "net value," as defined in Treasury Regulations under Section 752 of the Code, but will have a share, generally based on his share of profits, of our nonrecourse liabilities. Please read "—Disposition of Common Units—Recognition of Gain or Loss."

        Limitations on Deductibility of Losses.    Under Sections 704 and 465 of the Code, the deduction by a unitholder of his share of our losses will be limited to the tax basis in his units and, in the case of an individual unitholder, estate, trust, or corporate unitholder (if more than 50.0% of the value of the corporate unitholder's stock is owned directly or indirectly by or for five or fewer individuals or some

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tax-exempt organizations) to the amount for which the unitholder is considered to be "at-risk" with respect to our activities, if that is less than his tax basis. A common unitholder subject to these limitations must recapture losses deducted in previous years to the extent that distributions cause his at-risk amount to be less than zero at the end of any taxable year. Losses disallowed to a unitholder or recaptured as a result of these limitations will carry forward and will be allowable as a deduction to the extent that his at-risk amount is subsequently increased, provided such losses do not exceed such common unitholder's tax basis in his common units. Upon the taxable disposition of a unit, any gain recognized by a unitholder can be offset by losses that were previously suspended by the at-risk limitation but may not be offset by losses suspended by the basis limitation. Any loss previously suspended by the at-risk limitation in excess of that gain would no longer be utilizable.

        In general, a unitholder will be at-risk to the extent of the tax basis of his units, excluding any portion of that basis attributable to his share of our nonrecourse liabilities, reduced by (i) any portion of that basis representing amounts otherwise protected against loss because of a guarantee, stop loss agreement or other similar arrangement and (ii) any amount of money he borrows to acquire or hold his units, if the lender of those borrowed funds owns an interest in us, is related to another unitholder or can look only to the units for repayment. A unitholder's at-risk amount will increase or decrease as the tax basis of the unitholder's units increases or decreases, other than tax basis increases or decreases attributable to increases or decreases in his share of our nonrecourse liabilities.

        In addition to the basis and at-risk limitations on the deductibility of losses, the passive loss limitations of Code Section 469 generally provide that individuals, estates, trusts and some closely-held corporations and personal service corporations can deduct losses from passive activities, which are generally defined as trade or business activities in which the taxpayer does not materially participate, only to the extent of the taxpayer's income from those passive activities. The passive loss limitations are applied separately with respect to each publicly traded partnership. Consequently, any passive losses we generate will only be available to offset our passive income generated in the future and will not be available to offset income from other passive activities or investments, including our investments or a unitholder's investments in other publicly traded partnerships, or salary or active business income. Passive losses that are not deductible because they exceed a unitholder's share of income we generate may be deducted in full when he disposes of his entire investment in us in a fully taxable transaction with an unrelated party. The passive loss limitations are applied after other applicable limitations on deductions, including the at-risk rules and the basis limitation.

        A unitholder's share of our net income may be offset by any of our suspended passive losses, but it may not be offset by any other current or carryover losses from other passive activities, including those attributable to other publicly traded partnerships.

        Limitations on Interest Deductions.    Section 163 of the Code generally limits the deductibility of a non-corporate taxpayer's "investment interest expense" to the amount of that taxpayer's "net investment income." Investment interest expense includes:

    interest on indebtedness properly allocable to property held for investment;

    our interest expense attributed to portfolio income; and

    the portion of interest expense incurred to purchase or carry an interest in a passive activity to the extent attributable to portfolio income.

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        The computation of a unitholder's investment interest expense will take into account interest on any margin account borrowing or other loan incurred to purchase or carry a unit. Net investment income includes gross income from property held for investment and amounts treated as portfolio income under the passive loss rules, less deductible expenses, other than interest, directly connected with the production of investment income, but generally does not include gains attributable to the disposition of property held for investment or (if applicable) qualified dividend income. The IRS has indicated in Notice 88-75, 1988-2 C.B. 386, that the net passive income earned by a publicly traded partnership will be treated as investment income to its unitholders. In addition, the unitholder's share of our portfolio income will be treated as investment income.

        Entity-Level Collections.    If we are required or elect under applicable law to pay any federal, state, local or foreign income tax on behalf of any unitholder or our general partner or any former unitholder, we are authorized to pay those taxes from our funds. That payment, if made, will be treated as a distribution of cash to the unitholder on whose behalf the payment was made. If the payment is made on behalf of a person whose identity cannot be determined, we are authorized to treat the payment as a distribution to all current unitholders. We are authorized to amend our partnership agreement in the manner necessary to maintain uniformity of intrinsic tax characteristics of units and to adjust later distributions, so that after giving effect to these distributions, the priority and characterization of distributions otherwise applicable under our partnership agreement is maintained as nearly as is practicable. Payments by us as described above could give rise to an overpayment of tax on behalf of an individual unitholder in which event the unitholder would be required to file a claim in order to obtain a credit or refund.

        Allocation of Income, Gain, Loss and Deduction.    In general, under Section 704 of the Code, if we have a net profit, our items of income, gain, loss and deduction will be allocated among our general partner and the unitholders in accordance with their percentage interests in us. At any time that incentive distributions are made to our general partner, gross income will be allocated to the recipients to the extent of those distributions. If we have a net loss, that loss will be allocated first to our general partner and the unitholders in accordance with their percentage interests in us to the extent of their positive capital accounts and, second, to our general partner.

        Section 704(c) of the Code and related Treasury Regulations require us to adjust the "book" basis of all assets held by us prior to an issuance of additional units to equal their fair market values at the time of unit issuance. Purchasers of units in an offering are entitled to calculate tax depreciation and amortization deductions and other relevant tax items with respect to our assets based upon that "book" basis, which effectively puts purchasers in that offering in the same position as if our assets had a tax basis equal to their fair market value at the time of unit issuance. This may have the effect of decreasing the amount of our tax depreciation or amortization deductions thereafter allocated to purchasers of units in an earlier offering or of requiring purchasers of units in an earlier offering to thereafter recognize "remedial income" rather than depreciation and amortization deductions. In this context, we use the term "book" as that term is used in Treasury Regulations under Section 704 of the Code. The "book" basis assigned to our assets for this purpose may not be the same as the book value of our property for financial reporting purposes.

        It may not be administratively feasible to make the relevant adjustments to "book" basis and the relevant Section 704(c) allocations separately each time we issue units. If that is the case, we may use simplifying conventions to make those adjustments and allocations, which may include the aggregation of certain issuances of units. Our counsel, Baker Botts L.L.P., is unable to opine as to the validity of such conventions.

        In addition, items of recapture income will be allocated to the extent possible to the unitholder who was allocated the deduction giving rise to the treatment of that gain as recapture income in order to minimize the recognition of ordinary income by some unitholders. Finally, although we do not

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expect that our operations will result in the creation of negative capital accounts, if negative capital accounts nevertheless result, items of our income and gain will be allocated in an amount and manner sufficient to eliminate the negative balance as quickly as possible.

        An allocation of items of our income, gain, loss or deduction, other than an allocation required under the Section 704(c) principles described above, will generally be given effect for federal income tax purposes in determining a partner's share of an item of income, gain, loss or deduction only if the allocation has "substantial economic effect." In any other case, a partner's share of an item will be determined on the basis of his interest in us, which will be determined by taking into account all the facts and circumstances, including:

    his relative contributions to us;

    the interests of all the partners in profits and losses;

    the interests of all the partners in cash flows; and

    the rights of all the partners to distributions of capital upon liquidation.

        Baker Botts L.L.P. is of the opinion that, with the exception of the issues described in "—Section 754 Election," "—Disposition of Common Units—Allocations Between Transferors and Transferees," and "—Uniformity of Units," allocations under our partnership agreement will be given effect under Section 704 of the Code for federal income tax purposes in determining a partner's share of an item of income, gain, loss or deduction.

        Treatment of Securities Loans.    A unitholder whose units are loaned to a "short seller" to cover a short sale of units may be considered as having disposed of those units. If so, he would no longer be treated for tax purposes as a partner with respect to those units during the period of the loan and may recognize gain or loss from the disposition. As a result, during this period:

    any of our income, gain, loss or deduction with respect to those units would not be reportable by the unitholder;

    any cash distributions received by the unitholder as to those units would be fully taxable; and

    all of these distributions would appear to be ordinary income.

        Because there is no direct or indirect controlling authority on the issue relating to partnership interests, Baker Botts L.L.P. has not rendered an opinion regarding the tax treatment of a unitholder whose common units are loaned to a short seller to cover a short sale of common units; therefore, unitholders desiring to assure their status as partners and avoid the risk of gain recognition from a loan to a short seller are urged to modify any applicable brokerage account agreements to prohibit their brokers from borrowing and loaning their units. The IRS has previously announced in the preamble to certain temporary regulations, 53 FR 34488-01, 1988-2 C.B. 346, that it is studying issues relating to the tax treatment of short sales of partnership interests. Please also read "—Disposition of Common Units—Recognition of Gain or Loss."

        Alternative Minimum Tax.    Each unitholder will be required to take into account his distributive share of any items of our income, gain, loss or deduction for purposes of the alternative minimum tax. For many but not all noncorporate taxpayers, the current minimum tax is 26.0% on the first $185,400 of alternative minimum taxable income in excess of the exemption amount and 28.0% on any additional alternative minimum taxable income. Prospective unitholders are urged to consult with their tax advisors as to the impact of an investment in units on their liability for the alternative minimum tax.

        Tax Rates.    The highest marginal U.S. federal income tax rates applicable to ordinary income and long-term capital gains (generally, capital gains on certain assets held for more than twelve months) of

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individuals currently are 39.6% and 20.0%, respectively. These rates are subject to change by new legislation at any time.

        Section 1411 of the Code imposes a 3.8% Medicare tax on certain net investment income earned by individuals, estates and trusts. For these purposes, net investment income generally includes a unitholder's allocable share of our income and gain realized by a unitholder from a sale of units. In the case of an individual, the tax will be imposed on the lesser of (i) the unitholder's net investment income or (ii) the amount by which the unitholder's modified adjusted gross income exceeds $250,000 (if the unitholder is married and filing jointly or a surviving spouse), $125,000 (if the unitholder is married and filing separately) or $200,000 (in any other case). In the case of an estate or trust, the tax will be imposed on the lesser of (i) undistributed net investment income, or (ii) the excess adjusted gross income over the dollar amount at which the highest income tax bracket applicable to an estate or trust begins.

        Section 754 Election.    We will make the election permitted by Section 754 of the Code. That election is irrevocable without the consent of the IRS unless there is a constructive termination of the partnership. Please read "—Disposition of Common Units—Constructive Termination." The election will generally permit us to adjust a common unit purchaser's tax basis in our assets, or inside basis, under Section 743(b) of the Code to reflect his purchase price. This election does not apply with respect to a person who purchases common units directly from us. The Section 743(b) adjustment belongs to the purchaser and not to other unitholders. For purposes of this discussion, the inside basis in our assets with respect to a unitholder will be considered to have two components: (i) his share of our tax basis in our assets, or common basis, and (ii) his Section 743(b) adjustment to that basis.

        The timing of deductions attributable to a Section 743(b) adjustment to our common basis will depend upon a number of factors, including the nature of the assets to which the adjustment is allocable, the extent to which the adjustment offsets any Section 704(c) type gain or loss with respect to an asset and certain elections we make as to the manner in which we apply Section 704(c) principles with respect to an asset with respect to which the adjustment is allocable. Please read "—Allocation of Income, Gain, Loss and Deduction." The timing of these deductions may affect the uniformity of our units. Please read "—Uniformity of Units."

        A Section 754 election is advantageous if the transferee's tax basis in his units is higher than the units' share of the aggregate tax basis of our assets immediately prior to the transfer. In that case, as a result of the election, the transferee would have, among other items, a greater amount of depreciation deductions and his share of any gain or loss on a sale of our assets would be less. Conversely, a Section 754 election is disadvantageous if the transferee's tax basis in his units is lower than those units' share of the aggregate tax basis of our assets immediately prior to the transfer. Thus, the fair market value of the units may be affected either favorably or unfavorably by the election. A basis adjustment is required regardless of whether a Section 754 election is made in the case of a transfer of an interest in us if we have a substantial built-in loss immediately after the transfer, or if we distribute property and have a substantial basis reduction. Generally a built-in loss or a basis reduction is substantial if it exceeds $250,000.

        The calculations involved in the Section 754 election are complex and will be made on the basis of assumptions as to the value of our assets and other matters. For example, the allocation of the Section 743(b) adjustment among our assets must be made in accordance with the Code. The IRS could seek to reallocate some or all of any Section 743(b) adjustment allocated by us to our tangible assets to goodwill instead. Goodwill, as an intangible asset, is generally nonamortizable or amortizable over a longer period of time or under a less accelerated method than our tangible assets. We cannot assure you that the determinations we make will not be successfully challenged by the IRS and that the deductions resulting from them will not be reduced or disallowed altogether. Should the IRS require a different basis adjustment to be made, and should, in our opinion, the expense of compliance exceed

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the benefit of the election, we may seek permission from the IRS to revoke our Section 754 election. If permission is granted, a subsequent purchaser of units may be allocated more income than he would have been allocated had the election not been revoked.

Tax Treatment of Operations

        Accounting Method and Taxable Year.    We use the year ending December 31 as our taxable year and the accrual method of accounting for federal income tax purposes. Each unitholder will be required to include in income his share of our income, gain, loss and deduction for our taxable year ending within or with his taxable year. In addition, a unitholder who has a taxable year ending on a date other than December 31 and who disposes of all of his units following the close of our taxable year but before the close of his taxable year must include his share of our income, gain, loss and deduction in income for his taxable year, with the result that he will be required to include in income for his taxable year his share of more than twelve months of our income, gain, loss and deduction. Please read "—Disposition of Common Units—Allocations Between Transferors and Transferees."

        Tax Basis, Depreciation and Amortization.    The tax basis of our assets will be used for purposes of computing depreciation and cost recovery deductions and, ultimately, gain or loss on the disposition of these assets. Under Section 704 of the Code, the federal income tax burden associated with the difference between the fair market value of our assets and their tax basis immediately prior to an offering will be borne by our general partner and all of our unitholders as of that time. Please read "—Tax Consequences of Unit Ownership—Allocation of Income, Gain, Loss and Deduction."

        To the extent allowable, we may elect to use the depreciation and cost recovery methods, including bonus depreciation to the extent available, that will result in the largest deductions being taken in the early years after assets subject to these allowances are placed in service. Part or all of the goodwill, going concern value and other intangible assets we have acquired or will acquire may not produce any amortization deductions because of the application of the anti-churning restrictions of Section 197 of the Code. Please read "—Uniformity of Units." Property we subsequently acquire or construct may be depreciated using accelerated methods permitted by the Code.

        If we dispose of depreciable property by sale, foreclosure or otherwise, all or a portion of any gain, determined by reference to the amount of depreciation previously deducted and the nature of the property, may be subject to the recapture rules under Section 1245 or Section 1250 of the Code and taxed as ordinary income rather than capital gain. Similarly, a unitholder who has taken cost recovery or depreciation deductions with respect to property we own will likely be required to recapture some or all of those deductions as ordinary income upon a sale of his interest in us. Please read "—Tax Consequences of Unit Ownership—Allocation of Income, Gain, Loss and Deduction" and "—Disposition of Common Units—Recognition of Gain or Loss."

        The costs we incur in selling our units (called "syndication expenses") must be capitalized under Section 709 of the Code and cannot be deducted currently, ratably or upon our termination. There are uncertainties regarding the classification of costs as organization expenses, which may be amortized by us, and as syndication expenses, which may not be amortized by us. The underwriting discounts and commissions we incur will be treated as syndication expenses.

        Valuation and Tax Basis of Our Properties.    The federal income tax consequences of the ownership and disposition of units will depend in part on our estimates of the relative fair market values, and the initial tax bases, of our assets. Although we may from time to time consult with professional appraisers regarding valuation matters, we will make many of the relative fair market value estimates ourselves. These estimates and determinations of basis are subject to challenge and will not be binding on the IRS or the courts. If the estimates of fair market value or basis are later found to be incorrect, the character and amount of items of income, gain, loss or deductions previously reported by unitholders

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might change, and unitholders might be required to adjust their tax liability for prior years and incur interest and penalties with respect to those adjustments.

Disposition of Common Units

        Recognition of Gain or Loss.    Gain or loss will be recognized on a sale of units equal to the difference between the amount realized and the unitholder's tax basis for the units sold. A unitholder's amount realized will be measured by the sum of the cash or the fair market value of other property received by him plus his share of our nonrecourse liabilities. Because the amount realized includes a unitholder's share of our nonrecourse liabilities, the gain recognized on the sale of units could result in a tax liability in excess of any cash received from the sale.

        Prior distributions from us that in the aggregate were in excess of cumulative net taxable income for a common unit and, therefore, decreased a unitholder's tax basis in that common unit will, in effect, become taxable income if the common unit is sold at a price greater than the unitholder's tax basis in that common unit, even if the price received is less than his original cost.

        Except as noted below, gain or loss recognized by a unitholder, other than a "dealer" in units, on the sale or exchange of a unit will generally be taxable as capital gain or loss. Capital gain recognized by an individual on the sale of units held for more than twelve months will generally be taxed at a maximum U.S. federal income tax rate of 20.0%. However, a portion of this gain or loss, which will likely be substantial, will be separately computed and taxed as ordinary income or loss under Section 751 of the Code to the extent attributable to assets giving rise to depreciation recapture or other "unrealized receivables" or to "inventory items" we own. The term "unrealized receivables" includes potential recapture items, including depreciation recapture. Ordinary income attributable to unrealized receivables, inventory items and depreciation recapture may exceed net taxable gain realized upon the sale of a unit and may be recognized even if there is a net taxable loss realized on the sale of a unit. Thus, a unitholder may recognize both ordinary income and a capital loss upon a sale of units. Capital losses may offset capital gains and no more than $3,000 of ordinary income each year, in the case of individuals, and may only be used to offset capital gains in the case of corporations.

        The IRS ruled in Rev. Rul. 84-53, 1984-1 C.B. 159, that a partner who acquires interests in a partnership in separate transactions must combine those interests and maintain a single adjusted tax basis for all those interests. Upon a sale or other disposition of less than all of those interests, a portion of that tax basis must be allocated to the interests sold using an "equitable apportionment" method, which generally means that the tax basis allocated to the interest sold equals an amount that bears the same relation to the partner's tax basis in his entire interest in the partnership as the value of the interest sold bears to the value of the partner's entire interest in the partnership. Treasury Regulations under Section 1223 of the Code allow a selling unitholder who can identify common units transferred with an ascertainable holding period to elect to use the actual holding period of the common units transferred. Thus, according to the ruling discussed above, a common unitholder will be unable to select high or low basis common units to sell as would be the case with corporate stock, but, according to the Treasury Regulations, he may designate specific common units sold for purposes of determining the holding period of units transferred. A unitholder electing to use the actual holding period of common units transferred must consistently use that identification method for all subsequent sales or exchanges of common units. A unitholder considering the purchase of additional units or a sale of common units purchased in separate transactions is urged to consult his tax advisor as to the possible consequences of this ruling and application of the Treasury Regulations.

        Section 1259 of the Code can affect the taxation of some financial products and securities, including partnership interests, by treating a taxpayer as having sold an "appreciated" partnership

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interest, one in which gain would be recognized if it were sold, assigned or terminated at its fair market value, if the taxpayer or related persons enter(s) into:

    a short sale;

    an offsetting notional principal contract; or

    a futures or forward contract;

in each case, with respect to the partnership interest or substantially identical property.

        Moreover, if a taxpayer has previously entered into a short sale, an offsetting notional principal contract or a futures or forward contract with respect to the partnership interest, the taxpayer will be treated as having sold that position if the taxpayer or a related person then acquires the partnership interest or substantially identical property. The Secretary of the Treasury is also authorized to issue regulations that treat a taxpayer that enters into transactions or positions that have substantially the same effect as the preceding transactions as having constructively sold the financial position.

        Allocations Between Transferors and Transferees.    In general, our taxable income and losses will be determined annually, will be prorated on a monthly basis and will be subsequently apportioned among the unitholders in proportion to the number of units owned by each of them as of the opening of the applicable exchange on the first business day of the month, which we refer to in this prospectus as the "Allocation Date." However, gain or loss realized on a sale or other disposition of our assets other than in the ordinary course of business will be allocated among the unitholders on the Allocation Date in the month in which that gain or loss is recognized. As a result, a unitholder transferring units may be allocated income, gain, loss and deduction realized after the date of transfer.

        Although simplifying conventions are contemplated by the Code and most publicly traded partnerships use similar simplifying conventions, the use of this method may not be permitted under existing Treasury Regulations as there is no direct or indirect controlling authority on this issue. Even though the Department of the Treasury and the IRS have issued proposed Treasury Regulations under Section 706 of the Code that provide a safe harbor pursuant to which a publicly traded partnership may use a similar monthly simplifying convention to allocate tax items among transferor and transferee unitholders, the proposed regulations do not specifically authorize the use of the proration method we have adopted. Existing publicly traded partnerships are entitled to rely on these proposed Treasury Regulations; however, they are not binding on the IRS and are subject to change until final Treasury Regulations are issued. Accordingly, Baker Botts L.L.P. is unable to opine on the validity of this method of allocating income and deductions between transferor and transferee unitholders because the issue has not been finally resolved by the IRS or the courts. If this method is not allowed under the Treasury Regulations, or only applies to transfers of less than all of the unitholder's interest, our taxable income or losses might be reallocated among the unitholders. We are authorized to revise our method of allocation between transferor and transferee unitholders, as well as unitholders whose interests vary during a taxable year, to conform to a method permitted under future Treasury Regulations.

        A unitholder who disposes of units prior to the record date set for a cash distribution for any quarter will be allocated items of our income, gain, loss and deductions attributable to the month of sale but will not be entitled to receive that cash distribution.

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        Notification Requirements.    A unitholder who sells any of his units is generally required by regulations under Section 6050K of the Code to notify us in writing of that sale within 30 days after the sale (or, if earlier, January 15 of the year following the sale). A purchaser of units who purchases units from another unitholder is also generally required under Section 743 of the Code to notify us in writing of that purchase within 30 days after the purchase. Upon receiving such notifications, we are required to notify the IRS of that transaction and to furnish specified information to the transferor and transferee. Failure to notify us of a sale may lead to the imposition of penalties under Section 6723 of the Code. However, these reporting requirements do not apply to a sale by an individual who is a citizen of the U.S. and who effects the sale or exchange through a broker who will satisfy such requirements.

        Constructive Termination.    We will be considered under Section 708 of the Code to have terminated our tax partnership for federal income tax purposes upon the sale or exchange of our interests that, in the aggregate, constitute 50.0% or more of the total interests in our capital and profits within a twelve-month period. For purposes of measuring whether the 50.0% threshold is reached, multiple sales of the same interest are counted only once. A constructive termination results in the closing of our taxable year for all unitholders. In the case of a unitholder reporting on a taxable year other than a fiscal year ending December 31, the closing of our taxable year may result in more than twelve months of our taxable income or loss being includable in his taxable income for the year of termination. A constructive termination occurring on a date other than December 31 will result in us filing two tax returns (and unitholders could receive two Schedules K-1 if the relief discussed below is not available) for one fiscal year and the cost of the preparation of these returns will be borne by all common unitholders. We would be required to make new tax elections after a termination, including a new election under Section 754 of the Code, and a termination would result in a deferral of our deductions for depreciation. A termination could also result in penalties if we were unable to determine that the termination had occurred. Moreover, a termination might either accelerate the application of, or subject us to, any tax legislation enacted before the termination. The IRS also provides in an Industry Director Communication, LMSB-04-0210-006, a relief procedure whereby if a publicly traded partnership that has technically terminated requests publicly traded partnership technical termination relief and the IRS grants such relief, among other things, the partnership will only have to provide one Schedule K-1 to unitholders for the year notwithstanding two partnership tax years.

Uniformity of Units

        Because we cannot match transferors and transferees of units, we must maintain uniformity of the economic and tax characteristics of the units to a purchaser of these units. In the absence of uniformity, we may be unable to completely comply with a number of federal income tax requirements, both statutory and regulatory. Any non-uniformity could have an impact upon the value of our units. The timing of deductions attributable to Section 743(b) adjustments to the common basis of our assets with respect to persons purchasing units from another unitholder may affect the uniformity of our units. Please read "—Tax Consequences of Unit Ownership—Section 754 Election."

        For example, some types of depreciable assets are not subject to the typical rules governing depreciation (under Section 168 of the Code) or amortization (under Section 197 of the Code). If we were to acquire any assets of that type, the timing of a unit purchaser's deductions with respect to Section 743(b) adjustments to the common basis of those assets might differ depending upon when and to whom the unit he purchased was originally issued. We do not currently expect to acquire any assets of that type. However, if we were to acquire a material amount of assets of that type, we intend to adopt tax positions as to those assets that will not result in any such lack of uniformity. Any such tax positions taken by us might result in allocations to some unitholders of smaller depreciation deductions than they would otherwise be entitled to receive. Baker Botts L.L.P. has not rendered an opinion with

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respect to those types of tax positions. Moreover, the IRS might challenge those tax positions. If we took such a tax position and the IRS successfully challenged the position, the uniformity of our units might be affected, and the gain from the sale of our units might be increased without the benefit of additional deductions. Please read "—Disposition of Common Units—Recognition of Gain or Loss."

        In addition, as described above at "—Tax Consequences of Unit Ownership—Allocation of Income, Gain, Loss and Deduction," if we aggregate multiple issuances of units for purposes of making adjustments to "book" basis and related tax allocations, we will treat each of our units as having the same capital account balance, regardless of the price actually paid by each purchaser of units in the aggregated offerings. Our counsel, Baker Botts L.L.P., is unable to opine as to validity of such an approach. We do not expect the number of affected units, or the differences between the purchase price of a unit and the initial capital account balance assigned to the unit, to be material, and we do not expect this convention to have a material effect upon the trading of our units.

Tax-Exempt Organizations and Other Investors

        Ownership of units by employee benefit plans, other tax-exempt organizations, non-resident aliens, foreign corporations and other foreign persons raises issues unique to those investors and, as described below to a limited extent, may have substantially adverse tax consequences to them. If you are a tax-exempt entity or a non-U.S. person, you should consult your tax advisor before investing in our common units.

        Employee benefit plans and most other organizations exempt from federal income tax, including individual retirement accounts and other retirement plans, are subject to federal income tax under Section 511 of the Code on unrelated business taxable income. Virtually all of our income allocated to a unitholder that is a tax-exempt organization will be unrelated business taxable income and will be taxable to it.

        Non-resident aliens and foreign corporations, trusts or estates that own units will be considered under Section 875 of the Code to be engaged in business in the U.S. because of the ownership of units. As a consequence, they will be required to file federal tax returns to report their share of our income, gain, loss or deduction and pay federal income tax at regular rates on their share of our net income or gain. Moreover, under rules applicable to publicly traded partnerships, we will withhold at the highest applicable effective tax rate from cash distributions made quarterly to foreign unitholders. Each foreign unitholder must obtain a taxpayer identification number from the IRS and submit that number to our transfer agent on a Form W-8BEN or applicable substitute form in order to obtain credit for these withholding taxes. A change in applicable law may require us to change these procedures.

        In addition, because a foreign corporation that owns units will be treated as engaged in a U.S. trade or business, that corporation may be subject to the U.S. branch profits tax under Section 884 of the Code at a rate of 30.0%, in addition to regular federal income tax, on its share of our income and gain, as adjusted for changes in the foreign corporation's "U.S. net equity," which is effectively connected with the conduct of a U.S. trade or business. That tax may be reduced or eliminated by an income tax treaty between the U.S. and the country in which the foreign corporate unitholder is a "qualified resident." In addition, this type of unitholder is subject to special information reporting requirements under Section 6038C of the Code.

        A foreign unitholder who sells or otherwise disposes of a common unit will be subject to U.S. federal income tax on gain realized from the sale or disposition of that unit to the extent the gain is effectively connected with a U.S. trade or business of the foreign unitholder. Under Rev. Rul. 91-32, 1991-1 C.B. 107, interpreting the scope of "effectively connected income," a foreign unitholder would be considered to be engaged in a trade or business in the U.S. by virtue of the U.S. activities of the partnership, and part or all of that unitholder's gain would be effectively connected with that unitholder's indirect U.S. trade or business. Moreover, under the Foreign Investment in Real Property

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Tax Act, a foreign common unitholder generally will be subject to U.S. federal income tax upon the sale or disposition of a common unit if (i) he owned (directly or constructively applying certain attribution rules) more than 5.0% of our common units at any time during the five-year period ending on the date of such disposition and (ii) 50.0% or more of the fair market value of all of our assets consisted of U.S. real property interests at any time during the shorter of the period during which such unitholder held the common units or the five-year period ending on the date of disposition. Currently, more than 50.0% of our assets consist of U.S. real property interests and we do not expect that to change in the foreseeable future. Therefore, foreign unitholders may be subject to federal income tax on gain from the sale or disposition of their units.

Administrative Matters

        Information Returns and Audit Procedures.    We intend to furnish to each unitholder, within 90 days after the close of each taxable year, specific tax information, including a Schedule K-1, which describes his share of our income, gain, loss and deduction for our preceding taxable year. In preparing this information, which will not be reviewed by counsel, we will take various accounting and reporting positions, some of which have been mentioned earlier, to determine each unitholder's share of income, gain, loss and deduction. We cannot assure you that those positions will yield a result that conforms to the requirements of the Code, Treasury Regulations or administrative interpretations of the IRS. Neither we nor Baker Botts L.L.P. can assure prospective unitholders that the IRS will not successfully contend in court that those positions are impermissible. Any challenge by the IRS could negatively affect the value of the units.

        The IRS may audit our federal income tax information returns. Adjustments resulting from an IRS audit may require each unitholder to adjust a prior year's tax liability, and possibly may result in an audit of his return. Any audit of a unitholder's return could result in adjustments not related to our returns as well as those related to our returns.

        Partnerships generally are treated as separate entities under Section 6221 of the Code for purposes of federal tax audits, judicial review of administrative adjustments by the IRS and tax settlement proceedings. The tax treatment of partnership items of income, gain, loss and deduction are determined in a partnership proceeding rather than in separate proceedings with the partners. The Code requires that one partner be designated as the "Tax Matters Partner" for these purposes. Our partnership agreement names our general partner as our Tax Matters Partner.

        The Tax Matters Partner has made and will make some elections on our behalf and on behalf of unitholders. In addition, the Tax Matters Partner can extend the statute of limitations for assessment of tax deficiencies against unitholders for items in our returns. The Tax Matters Partner may bind a unitholder with less than a 1.0% profits interest in us to a settlement with the IRS unless that unitholder elects, by filing a statement with the IRS, not to give that authority to the Tax Matters Partner. The Tax Matters Partner may seek judicial review, by which all the unitholders are bound, of a final partnership administrative adjustment and, if the Tax Matters Partner fails to seek judicial review, judicial review may be sought by any unitholder having at least a 1.0% interest in profits or by any group of unitholders having in the aggregate at least a 5.0% interest in profits. However, only one action for judicial review will go forward, and each unitholder with an interest in the outcome may participate.

        A unitholder must file a statement with the IRS pursuant to Section 6222 of the Code identifying the treatment of any item on his federal income tax return that is not consistent with the treatment of the item on our return. Intentional or negligent disregard of this consistency requirement may subject a unitholder to substantial penalties.

        Additional Withholding Requirements.    Withholding taxes may apply to certain types of payments made to "foreign financial institutions" (as specially defined in the Code) and certain other non-U.S.

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entities. Specifically, a 30.0% withholding tax may be imposed on interest, dividends and other fixed or determinable annual or periodical gains, profits and income from sources within the U.S. (FDAP Income), or gross proceeds from the sale or other disposition of any property of a type which can produce interest or dividends from sources within the U.S. (Gross Proceeds) paid to a foreign financial institution or to a "non-financial foreign entity" (as specially defined in the Code), unless (i) the foreign financial institution undertakes certain diligence and reporting, (ii) the non-financial foreign entity either certifies it does not have any substantial U.S. owners or furnishes identifying information regarding each substantial U.S. owner or (iii) the foreign financial institution or non-financial foreign entity otherwise qualifies for an exemption from these rules. If the payee is a foreign financial institution and is subject to the diligence and reporting requirements in clause (i) above, it must enter into an agreement with the U.S. Treasury requiring, among other things, that it undertake to identify accounts held by certain U.S. persons or U.S.-owned foreign entities, annually report certain information about such accounts, and withhold 30.0% on payments to noncompliant foreign financial institutions and certain other account holders. An intergovernmental agreement between the United States and an applicable foreign country, or future Treasury Regulations, may modify these requirements.

        These rules generally apply to payments of FDAP Income currently and generally will apply to payments of relevant Gross Proceeds made on or after January 1, 2017. Thus, to the extent we have FDAP Income or will have Gross Proceeds on or after January 1, 2017 that are not treated as effectively connected with a U.S. trade or business (please read "—Tax-Exempt Organizations and Other Investors"), unitholders who are foreign financial institutions or certain other non-U.S. entities may be subject to withholding on distributions they receive from us, or their distributive share of our income, pursuant to the rules described above.

        Prospective investors should consult their own tax advisors regarding the potential application of these withholding provisions to their investment in our common units.

        Nominee Reporting.    Persons who hold an interest in us as a nominee for another person are required under Section 6031 of the Code to furnish to us:

    the name, address and taxpayer identification number of the beneficial owner and the nominee;

    a statement regarding whether the beneficial owner is:

    a person that is not a U.S. person;

    a foreign government, an international organization or any wholly-owned agency or instrumentality of either of the foregoing; or

    a tax-exempt entity;

    the amount and description of units held, acquired or transferred for the beneficial owner; and

    specific information including the dates of acquisitions and transfers, means of acquisitions and transfers, and acquisition cost for purchases, as well as the amount of net proceeds from sales.

        Brokers and financial institutions are required under Section 6031 of the Code to furnish additional information, including whether they are U.S. persons and specific information on units they acquire, hold or transfer for their own account. A penalty of $100 per failure, up to a maximum of $1.5 million per calendar year, is imposed by Section 6722 of the Code for failure to report that information to us. The nominee is required to supply the beneficial owner of the units with the information furnished to us.

        Accuracy-Related Penalties.    An additional tax equal to 20.0% of the amount of any portion of an underpayment of tax that is attributable to one or more specified causes, including negligence or disregard of rules or regulations, substantial understatements of income tax and substantial valuation

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misstatements, is imposed under Section 6662 of the Code. No penalty will be imposed, however, for any portion of an underpayment if it is shown that there was a reasonable cause for that portion and that the taxpayer acted in good faith regarding that portion.

        For individuals, a substantial understatement of income tax in any taxable year exists if the amount of the understatement exceeds the greater of 10.0% of the tax required to be shown on the return for the taxable year or $5,000 ($10,000 for most corporations). The amount of any understatement subject to penalty generally is reduced if any portion is attributable to a position adopted on the return:

    for which there is, or was, "substantial authority"; or

    as to which there is a reasonable basis and the pertinent facts of that position are disclosed on the return.

        If any item of income, gain, loss or deduction included in the distributive shares of unitholders might result in that kind of an "understatement" of income for which no "substantial authority" exists, we must disclose the pertinent facts on our return. In addition, we will make a reasonable effort to furnish sufficient information for unitholders to make adequate disclosure on their returns and to take other actions as may be appropriate to permit unitholders to avoid liability for this penalty. More stringent rules apply to "tax shelters," which we do not believe includes us, or any of our investments, plans or arrangements.

        A substantial valuation misstatement exists if (a) the value of any property, or the adjusted basis of any property, claimed on a tax return is 150.0% or more of the amount determined to be the correct amount of the valuation or adjusted basis, (b) the price for any property or services (or for the use of property) claimed on any such return with respect to any transaction between persons described in Section 482 of the Code is 200.0% or more (or 50.0% or less) of the amount determined under Code Section 482 to be the correct amount of such price, or (c) the net Section 482 transfer price adjustment for the taxable year exceeds the lesser of $5 million or 10.0% of the taxpayer's gross receipts. No penalty is imposed unless the portion of the underpayment attributable to a substantial valuation misstatement exceeds $5,000 ($10,000 for most corporations). If the valuation claimed on a return is 200.0% or more than the correct valuation or certain other thresholds are met, the penalty imposed increases to 40.0%. We do not anticipate making any valuation misstatements.

        In addition, the 20.0% accuracy-related penalty also applies to any portion of an underpayment of tax that is attributable to transactions lacking economic substance. To the extent that such transactions are not disclosed, the penalty imposed is increased to 40.0%. Additionally, there is no reasonable cause defense to the imposition of this penalty to such transactions.

        Reportable Transactions.    If we were to engage in a "reportable transaction," we (and possibly you and others) would be required under Treasury Regulations under Section 6011 of the Code and related provisions to make a detailed disclosure of the transaction to the IRS. A transaction may be a reportable transaction based upon any of several factors, including the fact that it is a type of tax avoidance transaction publicly identified by the IRS as a "listed transaction" or that it produces certain kinds of losses for partnerships, individuals, S corporations, and trusts in excess of $2 million in any single year, or $4 million in any combination of six successive tax years. Our participation in a reportable transaction could increase the likelihood that our federal income tax information return (and possibly your tax return) would be audited by the IRS. Please read "—Information Returns and Audit Procedures."

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        Moreover, if we were to participate in a reportable transaction with a significant purpose to avoid or evade tax, or in any listed transaction, you may be subject to the following provisions of the American Jobs Creation Act of 2004:

    accuracy-related penalties with a broader scope, significantly narrower exceptions, and potentially greater amounts than described above at "—Accuracy-Related Penalties";

    for those persons otherwise entitled to deduct interest on federal tax deficiencies, nondeductibility of interest on any resulting tax liability; and

    in the case of a listed transaction, an extended statute of limitations.

        We do not expect to engage in any "reportable transactions."

State, Local, Foreign and Other Tax Considerations

        In addition to federal income taxes, you likely will be subject to other taxes, such as state, local and foreign income taxes, unincorporated business taxes, and estate, inheritance or intangible taxes that may be imposed by the various jurisdictions in which we do business or own property or in which you are a resident. We currently do business or own property in several states, most of which impose personal income taxes on individuals. Most of these states also impose an income or gross receipts tax on corporations and other entities. Moreover, we may also own property or do business in other states in the future that impose income or similar taxes on nonresident individuals. Although an analysis of those various taxes is not presented here, each prospective unitholder should consider their potential impact on his investment in us. A unitholder may be required to file income tax returns and to pay income taxes in many of these jurisdictions in which we do business or own property and may be subject to penalties for failure to comply with those requirements. In some jurisdictions, tax losses may not produce a tax benefit in the year incurred and may not be available to offset income in subsequent taxable years. Some of the jurisdictions may require us, or we may elect, to withhold a percentage of income from amounts to be distributed to a unitholder who is not a resident of the jurisdiction. Withholding, the amount of which may be greater or less than a particular unitholder's income tax liability to the jurisdiction, generally does not relieve a nonresident unitholder from the obligation to file an income tax return. Amounts withheld will be treated as if distributed to unitholders for purposes of determining the amounts distributed by us. Please read "—Tax Consequences of Unit Ownership—Entity-Level Collections." Based on current law and our estimate of our future operations, our general partner anticipates that any amounts required to be withheld will not be material.

        It is the responsibility of each unitholder to investigate the legal and tax consequences, under the laws of pertinent jurisdictions, of his investment in us. Accordingly, each prospective unitholder is urged to consult, and depend upon, his tax counsel or other advisor with regard to those matters. Further, it is the responsibility of each unitholder to file all state, local and foreign, as well as U.S. federal tax returns, that may be required of him. Baker Botts L.L.P. has not rendered an opinion on the state, local or foreign tax consequences of an investment in us.

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PLAN OF DISTRIBUTION

        We may sell the securities being offered hereby in and outside the U.S. (1) through underwriters or underwriting syndicates led by one or more managing underwriters, (2) to or through brokers or dealers, (3) to or through agents, (4) directly to one or more purchasers, including our affiliates, (5) pursuant to delayed delivery contracts or forward contracts or (6) through a combination of any of these methods.

        The prospectus supplement will set forth the terms of the offering and the method of distribution and will include the following information:

    the names of any underwriters or agents;

    the name or names of any managing underwriter or underwriters;

    the purchase price of the securities from us;

    the net proceeds to us from the sale of the securities;

    any delayed delivery arrangements;

    any over-allotment options under which underwriters may purchase additional securities from us;

    any underwriting discounts, commissions and other items constituting compensation to underwriters, dealers or agents;

    any public offering price;

    any discounts or concessions allowed or reallowed or paid to dealers;

    any commissions paid to agents; and

    any securities exchange or market on which the securities offered in the prospectus supplement may be listed.

Sale Through Underwriters or Dealers

        If we use underwriters in the sale of securities, we will execute an underwriting agreement with the underwriter at the time of sale and we will provide the name of any underwriter in the prospectus supplement that the underwriter will use to make resales of securities to the public. The underwriters will acquire the securities for their own account, and the underwriters may resell the securities from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. Underwriters may offer securities to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more firms acting as underwriters. The obligations of the underwriters to purchase the securities will be subject to conditions, and any underwritten offering may be on a firm commitment basis. The underwriters may change from time to time any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers.

        If we use dealers in the sale of securities, we will sell the securities to them as principals. They may then resell those securities to the public at varying prices determined by the dealers at the time of resale. The dealers participating in any sale of the securities may be deemed to be underwriters within the meaning of the Securities Act, with respect to any sale of those securities. We will include in the prospectus supplement the names of the dealers and the terms of the transaction.

        To the extent that we make sales through one or more underwriters or agents in at-the-market offerings, we will do so pursuant to the terms of a sales agency financing agreement or other at-the-market offering arrangement between us and the underwriters or agents. If we engage in at-the-market sales pursuant to any such agreement, we will issue and sell common units through one

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or more underwriters or agents, which may act on an agency basis or on a principal basis. During the term of any such agreement, we may sell common units on a daily basis in exchange transactions or otherwise as we agree with the underwriters or agents. The agreement will provide that any common units sold will be sold at prices related to the then prevailing market prices for such securities. Therefore, exact figures regarding proceeds that will be raised or commissions to be paid cannot be determined at this time. Pursuant to the terms of the agreement, we also may agree to sell, and the relevant underwriters or agents may agree to solicit offers to purchase, blocks of common units. The terms of each such agreement will be set forth in more detail in the applicable prospectus supplement and any related free writing prospectus. In the event that any underwriter or agent acts as principal, or broker-dealer acts as underwriter, it may engage in certain transactions that stabilize, maintain, or otherwise affect the price of our common units. We will describe any such activities in the prospectus supplement or any related free writing prospectus relating to the transaction.

Sales Through Agents

        We may also sell the securities through agents we designate from time to time. In the prospectus supplement, we will name any agent involved in the offer or sale of the offered securities, and we will describe any commissions payable by us to the agent. Unless we inform you otherwise in the prospectus supplement, any agent will agree to use its reasonable best efforts to solicit purchases for the period of its appointment.

Direct Sales

        We may sell the securities directly. In that event, no underwriters or agents would be involved. We may use electronic media, including the Internet, to sell offered securities directly.

General Information

        In connection with the sale of the securities, underwriters, dealers or agents may be deemed to have received compensation from us in the form of underwriting discounts or commissions and may also receive commissions from securities purchasers for whom they may act as agent. Underwriters may sell the securities to or through dealers, and the dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters or commissions from the purchasers for whom they may act as agent. We will provide in the applicable prospectus supplement information regarding any underwriting discounts or other compensation that we pay to underwriters or agents in connection with the securities offering, and any discounts, concessions or commissions which underwriters allow to dealers.

        We may have agreements with the agents, dealers and underwriters to indemnify them against certain civil liabilities, including liabilities under the Securities Act, or to contribute with respect to payments that the agents, dealers or underwriters may be required to make because of those liabilities. Agents, dealers and underwriters, or their affiliates or associates, may be customers of, engage in transactions with or perform services for us in the ordinary course of their businesses.

        In connection with an offering, certain persons participating in the offering may make a market in the securities or engage in transactions that stabilize, maintain or otherwise affect the market price of the offered securities. This may include, among other transactions, over-allotments or short sales of the securities, which involves the sale by persons participating in the offering of more securities than we sold to them. In these circumstances, these persons would cover such over-allotments or short positions by making purchases in the open market or by exercising their over-allotment option. As a result, the price of the securities may be higher than the price that might otherwise prevail in the open market. If these activities are commenced, these transactions may be discontinued at any time.

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        Because FINRA views our common units as interests in a direct participation program, any offering of common units pursuant to this registration statement will be made in compliance with FINRA Rule 2310.

        To the extent required, this prospectus may be amended or supplemented from time to time to describe a specific plan of distribution. The place and time of delivery for the securities in respect of which this prospectus is delivered are set forth in the accompanying prospectus supplement.


LEGAL MATTERS

        In connection with particular offerings of the common units offered in this prospectus in the future, and if stated in the applicable prospectus supplements, the validity of the issuance of the common units and certain other legal matters will be passed upon for us by Baker Botts L.L.P., Houston, Texas. Baker Botts L.L.P. will also render an opinion on the material federal income tax considerations regarding the common units. If certain legal matters in connection with an offering of the common units made by this prospectus and a related prospectus supplement are passed on by counsel for the underwriters of such offering, that counsel will be named in the applicable prospectus supplement related to that offering.


EXPERTS

        The consolidated financial statements of EQT Midstream Partners, LP as of December 31, 2014 and 2013, and for each of the years in the three-year period ended December 31, 2014, appearing in EQT Midstream Partners, LP's Current Report on Form 8-K filed on April 1, 2015, and the effectiveness of EQT Midstream Partners, LP's internal control over financial reporting as of December 31, 2014 included in its Annual Report on Form 10-K have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their reports thereon, included therein, and incorporated by reference herein. Such financial statements are, and audited financial statements to be included in subsequently filed documents will be, incorporated herein in reliance upon the reports of Ernst & Young LLP pertaining to such financial statements and the effectiveness of our internal control over financial reporting as of the respective dates (to the extent covered by consents filed with the Securities and Exchange Commission) given on the authority of Ernst & Young LLP as experts in accounting and auditing.


WHERE YOU CAN FIND MORE INFORMATION

        We have filed a registration statement with the SEC under the Securities Act that registers the securities offered by this prospectus. The registration statement, including the attached exhibits, contains additional relevant information about us. The rules and regulations of the SEC allow us to omit some information included in the registration statement from this prospectus.

        In addition, we file annual, quarterly and other reports and other information with the SEC. You may read and copy any document we file at the SEC's public reference room at 100 F Street, N.E., Washington, D.C. 20549. Please call the SEC at 1-800-732-0330 for further information on the operation of the SEC's public reference room. Our SEC filings are available on the SEC's website at http://www.sec.gov. We also make available free of charge on our website at www.eqtmidstreampartners.com all materials that we file electronically with the SEC, including our annual report on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, Section 16 reports and amendments to these reports as soon as reasonably practicable after such materials are electronically filed with, or furnished to, the SEC. Information contained on our website or any other website is not incorporated by reference into this prospectus and does not constitute a part of this prospectus.

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        The SEC allows us to "incorporate by reference" the information we have filed with the SEC. This means that we can disclose important information to you without actually including the specific information in this prospectus by referring you to other documents filed separately with the SEC. These other documents contain important information about us, our financial condition and results of operations. The information incorporated by reference is an important part of this prospectus. Information that we file later with the SEC will automatically update and may replace information in this prospectus and information previously filed with the SEC.

        We incorporate by reference in this prospectus the documents listed below and any subsequent filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934 (excluding information deemed to be furnished and not filed with the SEC) until all offerings under this registration statement are completed:

    our annual report on Form 10-K for the year ended December 31, 2014;

    our quarterly reports on Form 10-Q for the quarters ended March 31, 2015 and June 30, 2015;

    our current reports on Form 8-K filed on January 22, 2015, March 10, 2015, March 17, 2015, March 31, 2015, April 1, 2015 and May 15, 2015 (in each case to the extent filed and not furnished); and

    the description of our common units in our registration statement on Form 8-A (File No. 001-35574) filed pursuant to the Securities Exchange Act of 1934 on June 18, 2012.

        You may obtain any of the documents incorporated by reference in this prospectus from the SEC through the SEC's website at the address provided above. You also may request a copy of any document incorporated by reference in this prospectus (including exhibits to those documents specifically incorporated by reference in those documents), at no cost, by visiting our internet website at www.eqtmidstreampartners.com, or by writing or calling us at the following address:

EQT Midstream Partners, LP
625 Liberty Avenue, Suite 1700
Pittsburgh, Pennsylvania 15222
Attention: Investor Relations
Telephone: (412) 553-5700

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LOGO

EQT Midstream Partners, LP

Common Units Representing Limited Partner Interests
Having an Aggregate Offering Price of up to $750,000,000



Prospectus Supplement

August 27, 2015



Deutsche Bank Securities   Barclays   BNP PARIBAS   BofA Merrill Lynch

Citigroup   Credit Suisse   Goldman, Sachs & Co.   J.P. Morgan

MUFG   RBC Capital Markets   Scotia Howard Weil

SunTrust Robinson Humphrey   U.S. Capital Advisors   Wells Fargo Securities