Mont. Code Ann. § 26-2-515

An employee of the state must receive all regular pay and benefits for time spent answering a subpoena when called to testify in connection with the employee's official duties in a civil action in which the state or one of its agencies is not a party. The person requesting issuance of the subpoena shall, if requested by the affected state agency, reimburse the agency for the compensation, including regular pay and benefits, paid to the employee for time spent answering the subpoena. As used in this section, "employee" means an employee of the executive, legislative, or judicial branch of state government.