SCHEDULE 13G/A 0001193125-24-258532 1000264 XXXXXXXX LIVE 1 Common Stock 12/31/2024 0001643615 Montrose Environmental Group, Inc. 615111101 5120 Northshore Drive North Little Rock AR 72118 Rule 13d-1(b) Alger Associates, Inc. NY 607051 0 1013896 0 1013896 N 3.0 HC Montrose Environmental Group, Inc. 5120 Northshore Drive, North Little Rock, AR 72118 Alger Associates, Inc. 100 Pearl Street, 27th Floor, New York, NY 10004 New York N HC 1,013,896 3.0% 607,051 0 1,013,896 0 N Y N The securities reported herein are beneficially owned by one or more open-end investment companies or other managed accounts that are investment management clients of Weatherbie Capital, LLC ("WC"), a registered investment adviser. Previously, Fred Alger Management, LLC ("FAM"), a registered investment adviser, also reported securities of the issuer, which were owned by one or more open-end investment companies or other managed accounts that are investment management clients of FAM. Each of FAM and WC is a 100% owned subsidiary of Alger Group Holdings, LLC ("AGH"), a holding company. AGH is a 100% owned subsidiary of Alger Associates, Inc., a holding company. N See Exhibit A. Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. Alger Associates, Inc. /s/ Hal Liebes 02/14/2025