(1) A member may not receive service credit or membership service in more than one retirement system, plan, or program under Title 19 for the same service. (2) A member may not receive service credit or membership service in more than one retirement system, plan, or program in Title 19 for the same period of military service.
No Duplication Of Benefits For Same Service
Mont. Code Ann. § 19-2-703, under Service Credit and Additional Contributions.
Mont. Code Ann. § 19-2-703