Mont. Code Ann. § 2-18-302

The department shall maintain a schedule of all salaries paid to personnel of civil executive state offices and shall only approve payroll claims agreeing with that schedule. All changes in personnel or salary status shall be authorized as provided by law, and the department shall alter the schedule accordingly when notified by the authorizing agency. However, no changes in personnel or salary status may be authorized that will cause an agency to exceed its appropriation or that will result in a deficiency or supplemental appropriation request to the legislature.