Mont. Code Ann. § 19-1-401

The department director, with the approval of the governor, may enter into an agreement on behalf of the state with the commissioner of social security, consistent with the terms and provisions of this chapter, for the purpose of extending the benefits of the federal old age and survivors' insurance system to employees of the state or any political subdivision of the state with respect to services specified in the agreement that constitute "employment", as defined in 19-1-102.