Michigan Compiled Laws, Chapter 38. Civil Service and Retirement § 38.1136

Sec. 16.  (1) An investment fiduciary may invest in annuity investment contracts or participations in separate real estate, mortgage, bond, stock, or other special investment accounts of a life insurance company authorized to do business in this state.  An investment in such a separate account shall be considered an investment in stock under section 14   1 only to the extent that the separate account's assets include stock, and then only for the purpose of determining the 70% maximum investment limit under section 14.  An investment in such a separate account shall also be considered an investment in real or personal property under section 19(1),  2 but only to the extent that the separate account's assets include real or personal property, and then only for the purpose of determining the 5% maximum investment limit under section 19(1).

(2) An investment fiduciary may invest in the general account of a life insurer authorized to do business in this state under the insurance code of 1956, 1956 PA 218, MCL 500.100 to 500.8302, but the total amount of assets of any 1 system invested in any 1 insurer shall not exceed 50% of the capital and surplus of the insurer.

(3) A life insurance company under this section shall have been in operation for at least 5 years and have assets under management of more than $500,000,000.00.  The insurance company shall have a claims-paying ability rating no less than single A according to A.M.  Best & company or AA- according to Duff & Phelps credit rating corp., and an overall company financial strength rating no less than Aa3 according to Moody's investors service, inc. or AA- according to Standard & Poor's ratings group.