ANTERO MIDSTREAM PARTNERS LP (NYSE:AM) Files An 8-K Entry into a Material Definitive Agreement
Item 1.01 Entry into a Material Definitive Agreement.

Underwriting Agreement

On September6, 2017, Antero Midstream Partners LP, a Delaware limited partnership (the “Partnership”), Antero Midstream Partners GP LLC, a Delaware limited liability company the general partner of the Partnership (the “General Partner”), and Antero Resources Corporation, a Delaware corporation (the “Selling Unitholder”), entered into an Underwriting Agreement (the “Underwriting Agreement”) with Barclays Capital Inc. and Wells Fargo Securities, LLC (the “Underwriters”), relating to the offer and sale by the Selling Unitholder of common units representing limited partner interests in the Partnership (the “Common Units”). The Underwriting Agreement provides for the offer and sale (the “Offering”) by the Selling Unitholder, and purchase by the Underwriters, of 10,000,000 Common Units at a price of $31.11. to the Underwriting Agreement, the Selling Unitholder has granted the Underwriters a 30-day option to purchase up to an aggregate of 1,500,000 additional Common Units. The material terms of the Offering are described in the prospectus, dated September6, 2016 (the “Prospectus”), filed by the Partnership with the Securities and Exchange Commission (the “Commission”) on September8, 2017, to Rule424(b)under the Securities Act of 1933, as amended (the “Securities Act”). The Offering is registered with the Commission to a Registration Statement on FormS-3 (File No.333-220359), filed by the Partnership on September6, 2017. The Partnership will not receive any proceeds from the sale of Common Units in the Offering. The Partnership will pay certain expenses, other than underwriting discounts and commissions, associated with the sale of Common Units in the Offering.

The Underwriting Agreement contains customary representations and warranties, agreements and obligations, closing conditions and termination provisions. The Partnership, the General Partner and the Selling Unitholder have agreed to indemnify the Underwriters against certain liabilities, including liabilities under the Securities Act, and to contribute to payments the Underwriters may be required to make because of any of those liabilities.

The Offering is expected to close on September11, 2017, subject to the satisfaction of customary closing conditions.

The foregoing description is qualified in its entirety by reference to the full text of the Underwriting Agreement, which is attached as Exhibit1.1 to this Current Report on Form8-K and incorporated in this Item 1.01 by reference.

Relationships

As more fully described under the caption “Underwriting” in the Prospectus, the Underwriters and their affiliates have, from time to time, performed, and may in the future perform, various financial advisory and investment banking services for the Partnership, for which they received or will receive customary fees and expenses. In particular, affiliates of Barclays Capital Inc. and Wells Fargo Securities, LLC are lenders under the Partnership’s credit facility.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.