Mich. Comp. Laws § 484.3220

Sec. 20. The notes and bonds of the authority are securities in which public officers and bodies of this state and municipalities and municipal subdivisions, insurance companies and associations and other persons carrying on an insurance business, banks, trust companies, savings banks and savings associations, savings and loan associations, investment companies, administrators, guardians, executors, trustees and other fiduciaries, and any other person who is now or may be authorized to invest in bonds or other obligations of this state, may properly and legally invest funds, including capital, in their control or belonging to them.