X0206 3 2021-01-07 0 0000010254 EARTHSTONE ENERGY INC ESTE 0001774131 Warburg Pincus Private Equity (E&P) XI-A, L.P. C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 0001774130 Warburg Pincus XI (E&P) Partners - A, L.P. C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 0001840237 WP IRH Holdings, L.P. C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 0001840108 Warburg Pincus XI (E&P) Partners-B IRH, LLC C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 0001676974 WARBURG PINCUS XI (E&P) PARTNERS-B, L.P. C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 0001678774 WARBURG PINCUS (E&P) XI, L.P. C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 0001678784 WARBURG PINCUS (E&P) XI LLC C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 0001678783 WARBURG PINCUS PARTNERS (E&P) XI LLC C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 0001162870 WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 Class A Common Stock 12719594 I See footnotes The shares reported herein are held of record by Independer Resources Holdings, LLC ("IRH LLC"). Warburg Pincus Private Equity (E&P) XI - A, L.P. ("WP E&P XI A"), Warburg Pincus XI (E&P) Partners - A, L.P. ("WP XI E&P Partners A"), WP IRH Holdings, L.P. ("WP IRH Holdings"), Warburg Pincus XI (E&P) Partners-B IRH, LLC ("WP XI E&P Partners B IRH"), WP Energy IRH Holdings, L.P. ("WPE IRH Holdings"), WP Energy Partners IRH Holdings, L.P. ("WPE Partners IRH Holdings"), Warburg Pincus Energy (E&P) Partners-B IRH, LLC ("WPE E&P Partners B IRH"), Warburg Pincus Energy (E&P) Partners-A, L.P. ("WPE E&P Partners A") and Warburg Pincus Energy (E&P)-A, L.P. ("WPE E&P A") collectively hold a majority of the membership interests in IRH LLC. Warburg Pincus XI (E&P) Partners - B, L.P. ("WP XI E&P Partners B") is the general partner of WP XI E&P Partners B IRH. Warburg Pincus (E&P) XI, L.P. ("WP XI E&P GP") is the general partner of WP E&P XI A, WP XI E&P Partners A, WP IRH Holdings, and WP XI E&P Partners B. Warburg Pincus (E&P) XI LLC ("WP XI E&P GP LLC") is the general partner of WP XI E&P GP. Warburg Pincus Partners (E&P) XI LLC ("WPP E&P XI") is the managing member of WP XI E&P GP LLC. Warburg Pincus Energy (E&P) Partners-B, L.P. ("WPE E&P Partners B") is the general partner of WPE E&P Partners B IRH. Warburg Pincus (E&P) Energy GP, L.P. ("WPE E&P GP") is the general partner of WPE IRH Holdings, WPE Partners IRH Holdings, WPE E&P Partners B, WPE E&P Partners A, and WPE E&P A. Warburg Pincus (E&P) Energy LLC ("WPE E&P GP LLC") is the general partner of WPE E&P GP. Warburg Pincus Partners II (US), L.P. ("WPP II US") is the managing member of WPP E&P XI and WPE E&P GP LLC. Warburg Pincus & Company US, LLC ("WP & Co. US LLC") is the general partner of WPP II US. Warburg Pincus LLC ("WP LLC") is a registered investment adviser, and the manager of WP E&P XI A, WP XI E&P Partners A, WPE E&P Partners A, and WPE E&P A. Due to the limitations of the electronic filing system certain Reporting Persons are filing a separate Form 3. Warburg Pincus Private Equity (E&P) XI - A, L.P., By: Warburg Pincus & Company US, LLC By: /s/ Robert B. Knauss, Authorized Signatory 2021-01-11 Warburg Pincus XI (E&P) Partners - A, L.P., By: Warburg Pincus & Company US, LLC By: /s/ Robert B. Knauss, Authorized Signatory 2021-01-11 WP IRH Holdings, L.P., By: Warburg Pincus & Company US, LLC By: /s/ Robert B. Knauss, Authorized Signatory 2021-01-11 Warburg Pincus XI (E&P) Partners-B IRH, LLC, By: Warburg Pincus & Company US, LLC By: /s/ Robert B. Knauss, Authorized Signatory 2021-01-11 Warburg Pincus XI (E&P) Partners - B, L.P., By: Warburg Pincus & Company US, LLC By: /s/ Robert B. Knauss, Authorized Signatory 2021-01-11 Warburg Pincus (E&P) XI, L.P., By: Warburg Pincus & Company US, LLC By: /s/ Robert B. Knauss, Authorized Signatory 2021-01-11 Warburg Pincus (E&P) XI LLC, By: Warburg Pincus & Company US, LLC By: /s/ Robert B. Knauss, Authorized Signatory 2021-01-11 Warburg Pincus Partners (E&P) XI LLC, By: Warburg Pincus & Company US, LLC By: /s/ Robert B. Knauss, Authorized Signatory 2021-01-11 Warburg Pincus LLC By: /s/ Robert B. Knauss, Authorized Signatory 2021-01-11