As filed with the Securities and Exchange Commission on February 7, 2018

Registration No. 333-222810

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Amendment No. 1

to

FORM S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

AMERICAN MIDSTREAM PARTNERS, LP

(Exact Name of Registrant as Specified in its Charter)

Copies To:

Hillary H. Holmes

Gibson, Dunn & Crutcher LLP

1221 McKinney Street, 37^th Floor

Houston, Texas 77010

(346) 718-6600

Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this Registration Statement.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box.  ☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box.  ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box.  ☐

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box.  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer, “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.  ☐

The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, or until the registration statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

EXPLANATORY NOTE

This Amendment No. 1 is being filed for the purpose of filing an updated Exhibit 8.1 to the Registration Statement (File No. 333-222810). No changes or additions are being made hereby to the Prospectus constituting Part I of the Registration Statement (not included herein) or to Items 14, 15, 16 or 17 of Part II of this Registration Statement.

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PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

The following sets forth the expenses in connection with the issuance and distribution of the securities being registered hereby, other than underwriting discounts and commissions.

Section 7.7(a) of the AMID Partnership Agreement, provides that American Midstream Partners, LP (“AMID”) will, to the fullest extent permitted by law but subject to the limitations expressly provided in the AMID Partnership Agreement, indemnify and hold harmless the following persons (together, the “Indemnitees”) from and against any and all losses, claims, damages, liabilities, joint or several, expenses (including legal fees and expenses), judgments, fines, penalties, interest, settlements or other amounts arising from any and all threatened pending or completed claims, demands, actions, suits or proceedings, whether civil, criminal, administrative or investigative, and whether formal or informal and including appeals, in which any Indemnitee may be involved, or is threatened to be involved, as a party or otherwise, by reason of its status as an Indemnitee and acting (or refraining to act) in such capacity:

provided, that the Indemnitee shall not be indemnified and held harmless pursuant to the AMID Partnership Agreement if there has been a final and non-appealable judgment entered by a court of competent jurisdiction

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determining that, in respect of the matter for which the Indemnitee is seeking indemnification pursuant to the AMID Partnership Agreement, the Indemnitee acted in bad faith or engaged in fraud, willful misconduct or, in the case of a criminal matter, acted with knowledge that the Indemnitee’s conduct was unlawful. Any indemnification pursuant to Section 7.7 of the AMID Partnership Agreement shall be made only out of the assets of the AMID, it being agreed that the AMID GP shall not be personally liable for such indemnification and shall have no obligation to contribute or loan any monies or property to AMID to enable it to effectuate such indemnification.

Section 7.7(b) of the AMID Partnership Agreement states that to the fullest extent permitted by law, expenses (including legal fees and expenses) incurred by an Indemnitee who is indemnified pursuant to Section 7.7(a) of the AMID Partnership Agreement in appearing at, participating in or defending any claim, demand, action, suit or proceeding shall, from time to time, be advanced by AMID prior to a final and non-appealable judgment entered by a court of competent jurisdiction determining that, in respect of the matter for which the Indemnitee is seeking indemnification, the Indemnitee is not entitled to be indemnified upon receipt by the AMID of any undertaking by or on behalf of the Indemnitee to repay such amount if it shall be ultimately determined that the Indemnitee is not entitled to be indemnified as authorized by this Section 7.7 of the AMID Partnership Agreement.

Section 7.7(d) of the AMID Partnership Agreement states that AMID may purchase and maintain insurance (or reimburse AMID GP or affiliates for the cost of), on behalf of AMID GP, its affiliates, the Indemnitees and such other persons as AMID GP shall determine, against any liability that may be asserted against, or expense that may be incurred by, such person in connection with AMID’s activities or such person’s activities on behalf of AMID, regardless of whether AMID would have the power to indemnify such person against such liability under the provisions of the AMID Partnership Agreement.

Section 17-108 of the Delaware Revised Uniform Limited Partnership Act provides that, subject to such standards and restrictions, if any, as are set forth in its partnership agreement, a Delaware limited partnership may, and shall have the power to, indemnify and hold harmless any partner or other person from and against any and all claims and demands whatsoever.

Section 18-108 of the Delaware Limited Liability Company Act provides that, subject to such standards and restrictions, if any, as are set forth in its limited liability company agreement, a Delaware limited liability company may, and shall have the power to, indemnify and hold harmless any member or manager or other person from and against any and all claims and demands whatsoever.

(a) The following is a list of exhibits filed as part of this Amendment No. 1 to the Registration Statement.

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(b) Financial Statement Schedules.

Not Applicable.

provided, however, that paragraphs (a)(1)(i), (a)(1)(ii) and (a)(1)(iii) do not apply if the registration statement is on Form S-3 and the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrants pursuant to section 13 or section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the registrant has duly caused this Amendment No. 1 to the Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Houston, State of Texas, on February 7, 2018.

Pursuant to the requirements of the Securities Act, this registration statement has been signed by the following persons in the indicated capacities, which are with American Midstream GP, LLC, the general partner of American Midstream Partners, LP, on February 7, 2018.

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