X0306 4 2019-03-12 0 0001623925 Antero Midstream Corp AM 0001528258 Warburg Pincus Private Equity X O&G, L.P. C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 1 0 1 0 0001414561 Warburg Pincus X, L.P. C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 1 0 1 0 0001414564 Warburg Pincus X GP L.P. C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 1 0 1 0 0001621874 WPP GP LLC C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 1 0 1 0 0001621242 Warburg Pincus Partners, L.P. C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 1 0 1 0 0001621224 Warburg Pincus Partners GP LLC C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 1 0 1 0 0000929408 WARBURG PINCUS & CO. C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK, NY 10017 1 0 1 0 0001162870 WARBURG PINCUS LLC C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 1 0 1 0 0001239318 KAYE CHARLES R C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 0001220638 Landy Joseph P. C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 Common Shares representing limited partner interests 2019-03-12 4 D 0 34834296 D 0 D Common Shares representing limited partner interests 2019-03-12 4 D 0 1114410 D 0 I See footnotes Common Shares representing limited partner interests 2019-03-12 4 D 0 53823 D 0 I See footnotes Common Shares representing limited partner interests 2019-03-12 4 D 0 19107060 D 0 I See footnotes Common Stock 2019-03-12 4 A 0 34834296 A 34834296 D Common Stock 2019-03-12 4 A 0 1114410 A 35948706 I See footnotes Common Stock 2019-03-12 4 A 0 53823 A 36002529 I See footnotes Common Stock 2019-03-12 4 A 0 19107060 A 55109589 I See footnotes On March 12, 2019, in connection with the conversion of Antero Midstream GP LP ("AMGP") from a limited partnership to a corporation named Antero Midstream Corporation ("New AM") under the laws of the State of Delaware (the "Conversion"), each common share representing limited partnership interests of AMGP (the "AMGP Common Shares") was converted into one share of common stock of New AM ("New AM Common Shares"). This Form 4 is filed on behalf of Warburg Pincus Private Equity X O&G, L.P., a Delaware limited partnership ("WP X O&G" and, together with its affiliated partnership, Warburg Pincus X Partners, L.P., a Delaware limited partnership ("WP X Partners"), the "WP X O&G Funds"). As of March 12, 2019, prior to the Conversion, the Warburg Pincus Entities (as defined below) collectively owned 55,109,589 AMGP Common Shares, of which (a) 34,834,296 are owned by WP X O&G and 1,114,410 are owned by WP X Partners, for an aggregate total of 35,948,706 AMGP Common Shares owned by the WP X O&G Funds, and (b) 19,160,883 are owned by the WP VIII Funds (as defined below). (Continued from Footnote 2) As of March 12, 2019, after the Conversion, the Warburg Pincus Entities collectively own 55,109,589 New AM Common Shares, of which (i) 34,834,296 are owned by WP X O&G and 1,114,410 are owned by WP X Partners, for an aggregate total of 35,948,706 New AM Common Shares owned by the WP X O&G Funds, and (ii) 19,160,883 are owned by the WP VIII Funds. The Warburg Pincus funds are the WP X O&G Funds and Warburg Pincus Private Equity VIII, L.P., a Delaware limited partnership ("WP VIII"), and its two affiliated partnerships, Warburg Pincus Netherlands Private Equity VIII C.V. I, a limited partnership formed under the laws of the Netherlands ("WP VIII CV I"), and WP-WPVIII Investors, L.P., a Delaware limited partnership ("WP-WPVIII Investors"), and together with WP VIII and WP VIII CV I, the "WP VIII Funds"). Warburg Pincus X, L.P., a Delaware limited partnership ("WP X GP"), is the general partner of each of the WP X O&G Funds. Warburg Pincus X GP L.P., a Delaware limited partnership ("WP X GP LP"), is the general partner of WP X GP. WPP GP LLC, a Delaware limited liability company ("WPP GP"), is the general partner of (a) WP X GP, and (b) WP-WPVIII Investors GP L.P., a Delaware limited partnership ("WP-WPVIII GP"), which, in turn, is the general partner of WP-WPVIII Investors. Warburg Pincus Partners, L.P., a Delaware limited partnership ("WP Partners"), is (i) the managing member of WPP GP, and (ii) the general partner of WP VIII and WP VIII CV I. Warburg Pincus Partners GP LLC, a Delaware limited liability company ("WP Partners GP"), is the general partner of WP Partners. Warburg Pincus & Co., a New York general partnership ("WP"), is the managing member of WP Partners GP. Warburg Pincus LLC, a New York limited liability company ("WP LLC"), is the manager of each of the WP X O&G Funds and the WP VIII Funds. Each of the WP X O&G Funds, the WP VIII Funds, WP-WPVIII GP, WP X GP, WP X GP LP, WPP GP, WP Partners, WP Partners GP, WP and WP LLC are collectively referred to herein as the "Warburg Pincus Entities." Charles R. Kaye and Joseph P. Landy are each Managing General Partners of WP and Managing Members and Co-Chief Executive Officers of WP LLC and may be deemed to control the Warburg Pincus Entities. By reason of the provisions of Rule 16a-1 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), (a) WP X GP, WP X GP LP, WPP GP, WP Partners, WP Partners GP, WP, WP LLC, and Messrs. Kaye and Landy and certain affiliates may be deemed to be beneficial owners of the 35,948,706 AMGP Common Shares (prior to the Conversion) and the 35,948,706 New AM Common Shares (after the Conversion) held collectively by the WP X O&G Funds, and (b) WPP GP, WP Partners, WP Partners GP, WP, WP LLC, and Messrs. Kaye and Landy and certain affiliates may be deemed to be beneficial owners of the 19,160,883 AMGP Common Shares (prior to the Conversion) and the 19,160,883 New AM Common Shares (after the Conversion) held collectively by the WP VIII Funds. (Continued from Footnote 8) The Warburg Pincus Entities, Messrs. Kaye and Landy and such affiliates disclaim beneficial ownership of such AMGP Common Shares and such New AM Common Shares except to the extent of their pecuniary interest therein. Each of WP X O&G, WP X GP, WP X GP LP, WPP GP, WP Partners, WP Partners GP, WP and WP LLC is a director-by-deputization solely for purposes of Section 16 of the Exchange Act. WP X GP and WP X GP LP each indirectly holds, and therefore may be deemed to be the beneficial owner of, the 35,948,706 AMGP Common Shares (prior to the Conversion) and the 35,948,706 New AM Common Shares (after the Conversion) directly held by the WP X O&G Funds. WPP GP indirectly holds, and therefore may be deemed to be the beneficial owner of, the 36,002,529 AMGP Common Shares (prior to the Conversion) and the 36,002,529 New AM Common Shares (after the conversion) directly held by WP-WPVIII Investors and the WP X O&G Funds. WP Partners, WP Partners GP, WP and WP LLC each indirectly holds, and therefore may be deemed to be the beneficial owner of, the 55,109,589 AMGP Common Shares (prior to the Conversion) and the 55,109,589 New AM Common Shares directly held by the WP VIII Funds and the WP X O&G Funds. Exhibit 99.1 - Joint Filers' Signatures /s/ Robert B. Knauss 2019-03-14