Mich. Comp. Laws § 35.551

Sec. 1. The status of any member of the armed forces of the United States, any auxiliary thereof, or the merchant marine or nurse, who was duly licensed to engage in any profession or occupation by this state, or was registered in meeting the preliminary requirements for any such license, at the time of induction or entering into any such service, shall remain unchanged and in full force and effect, without further action on the part of any such person, until discharged or until the leaving of any such service.