Mich. Comp. Laws § 38.111: Resignation or leave of absence; notice required.

Sec. 1.

No teacher on continuing tenure shall discontinue his services with any controlling board except by mutual consent, without giving a written notice to said controlling board at least 60 days before September first of the ensuing school year. Any teacher discontinuing his services in any other manner than as provided in this section shall forfeit his rights to continuing tenure previously acquired under this act.