Mont. Code Ann. § 19-9-410

When an injured nonvested member accepts a transfer under 7-32-4136 to a nonpolice position within the municipality covered under the public employees' retirement system, all service and contributions previously credited with the municipal police officers' retirement system must be transferred from the municipal police officers' retirement system pension trust fund along with the interest to the public employees' retirement system pension trust fund. The employer contributions and interest transferred must be equal to the amount that would have been contributed if the transferred service credit had been normal employment covered under the public employees' retirement system.