X0306 4 2021-03-18 0 0001643615 Montrose Environmental Group, Inc. MEG 0001817851 Afsari Nasym 1 PARK PLAZA, SUITE 1000 IRVINE CA 92614 0 1 0 0 General Counsel and Secretary Stock Option (Right to Buy) 47.72 2021-03-18 4 A 0 10563 0.00 A 2031-03-18 Common Stock 10563 10563 D This option represents the right to purchase a total of 10,563 shares of the Common Stock which will vest in two equal installments on September 18, 2021 and March 18, 2022, subject to the Reporting Person's continued service to the Issuer. /s/ Nasym Afsari 2021-03-19