Mich. Comp. Laws § 24.231

Sec. 31. (1) Rules which became effective before July 1, 1970 continue in effect until amended or rescinded. (2) When a law authorizing or directing an agency to promulgate rules is repealed and substantially the same rule-making power or duty is vested in the same or a successor agency by a new provision of law or the function of the agency to which the rules are related is transferred to another agency, by law or executive order, the existing rules of the original agency relating thereto continue in effect until amended or rescinded, and the agency or successor agency may rescind any rule relating to the function. When a law creating an agency or authorizing or directing it to promulgate rules is repealed or the agency is abolished and substantially the same rule-making power or duty is not vested in the same or a successor agency by a new provision of law and the function of the agency to which the rules are related is not transferred to another agency, the existing applicable rules of the original agency are automatically rescinded as of the effective date of the repeal of such law or the abolition of the agency. (3) The rescission of a rule does not revive a rule which was previously rescinded. (4) The amendment or rescission of a valid rule does not defeat or impair a right accrued, or affect a penalty incurred, under the rule. (5) Except in the case of the amendment of rules concerning inmates as described in section 7(k), a rule may be amended or rescinded by another rule which constitutes the whole or a part of a filing of rules or as a result of an act of the legislature.