Mich. Comp. Laws § 38.1021a

Sec. 21a. The state shall pick up the member contributions required by sections 21, 22, 22c, and 50a for all compensation earned after December 31, 1986. Contributions picked up shall be treated as employer contributions in determining tax treatment under the internal revenue code. The state shall pay these member contributions from the same source of funds that is used in paying compensation to the member. The state may pick up these contributions by a reduction in the cash salary of the member. Member contributions picked up shall be treated for all other purposes in the same manner and to the same extent as member contributions made before the date picked up.