Michigan Compiled Laws, Chapter 38. Civil Service and Retirement § 38.1326

Sec. 26.(1) This section does not apply to Tier 2.

(2) The state treasurer shall be treasurer of the retirement system and shall have investment authority, including the custodianship of the funds of the retirement system, and shall have fiduciary responsibility with regard to the investment of funds of the retirement system.

(3) The state treasurer shall deposit the funds of the retirement system in the same manner and subject to the law governing the deposit of state funds by the treasurer. Income earned by the retirement system's funds shall be credited to the respective reserves under this act that earned the income.