(a) Any department, agency or instrumentality of the state, county, city, municipality, or college or university operated by the state or any local government is authorized to participate in a program of interchange of employees with departments, agencies or instrumentalities of the federal government, another state or locality, or other agencies, municipalities, or instrumentalities of this state as a sending and/or receiving agency.

(b) The period of individual assignment or detail under an interchange program shall not exceed two years. However, the sending agency may extend the period of assignment for not more than two additional years. Details relating to any matter covered in this act may be the subject of an agreement between the sending and receiving agencies. Elected officials shall not be assigned from a sending agency nor detailed to a receiving agency.