X0306 4 2019-03-12 0 0001623925 Antero Midstream Corp AM 0001370287 Keenan W Howard JR C/O YORKTOWN PARTNERS LLC 410 PARK AVENUE, 19TH FLOOR NEW YORK NY 10022 1 0 0 0 Common shares representing limited partner interests 2019-03-12 4 D 0 9619 D 0 D Common shares representing limited partner interests 2019-03-12 4 D 0 1875802 D 0 I See footnote Common shares representing limited partner interests 2019-03-12 4 D 0 1970846 D 0 I See footnote Common shares representing limited partner interests 2019-03-12 4 D 0 4596064 D 0 I See footnote Common shares representing limited partner interests 2019-03-12 4 D 0 7091699 D 0 I See footnote Common Stock 2019-03-12 4 A 0 9619 A 9619 D Common Stock 2019-03-12 4 A 0 25613 A 35232 D Common Stock 2019-03-12 4 A 0 1875802 A 1875802 I See footnote Common Stock 2019-03-12 4 A 0 1970846 A 1970846 I See footnote Common Stock 2019-03-12 4 A 0 4596064 A 4596064 I See footnote Common Stock 2019-03-12 4 A 0 7091699 A 7091699 I See footnote 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 was converted into one share of common stock of New AM. The reporting person disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein, and this report shall not be deemed an admission that the reporting person is the beneficial owner of the securities for Section 16 or any other purpose. These securities are owned directly by Yorktown Energy Partners V, L.P. ("Yorktown V"). The reporting person is a member and manager of Yorktown V Company LLC, the general partner of Yorktown V. These securities are owned directly by Yorktown Energy Partners VI, L.P. ("Yorktown VI"). The reporting person is a member and manager of Yorktown VI Associates LLC, the general partner of Yorktown VI Company LP, the general partner of Yorktown VI. These securities are owned directly by Yorktown Energy Partners VII, L.P. ("Yorktown VII"). The reporting person is a member and manager of Yorktown VII Associates LLC, the general partner of Yorktown VII Company LP, the general partner of Yorktown VII. These securities are owned directly by Yorktown Energy Partners VIII, L.P. ("Yorktown VIII"). The reporting person is a member and manager of Yorktown VIII Associates LLC, the general partner of Yorktown VIII Company LP, the general partner of Yorktown VIII. On March 12, 2019, simultaneously with the Conversion, Antero Midstream Merger Sub LLC, a Delaware limited liability company and wholly owned subsidiary of Antero Midstream Newco Inc., a Delaware corporation and wholly owned subsidiary of New AM, was merged with and into Antero Midstream Partners LP, a Delaware limited partnership ("Antero Midstream"), with Antero Midstream surviving such merger as an indirect wholly owned subsidiary of New AM (the "Merger"), as a result of which all outstanding common units of Antero Midstream were converted into an aggregate of approximately $598.7 million in cash and approximately 303.1 million shares of common stock, par value $0.01 per share (the "Merger Shares"). In connection, with the Merger, the reporting person made an election to convert his outstanding common units of Antero Midstream into Merger Shares and cash for consideration of $3.415 in cash and 1.6350 in Merger Shares per outstanding common unit of Antero Midstream. /s/ W. Howard Keenan, Jr. 2019-03-14