Mont. Code Ann. § 19-9-705

All gifts, bequests, or emoluments given to an employer or member for the benefit of the retirement system or because of any member's service as a police officer, except when specifically allowed to be retained by the member by the member's employer, and all money withheld from the compensation of a member for violation of the rules of the member's employer must be paid to the pension trust fund. The amounts are employer contributions but are in addition to the amounts required by 19-9-703.