Mich. Comp. Laws § 15.602

Sec. 2. (1) Except as provided in subsection (2), a public employer shall not require, by collective bargaining agreement or otherwise, that a person reside within a specified geographic area or within a specified distance or travel time from his or her place of employment as a condition of employment or promotion by the public employer. (2) Subsection (1) does not prohibit a public employer from requiring, by collective bargaining agreement or otherwise, that a person reside within a specified distance from the nearest boundary of the public employer. However, the specified distance shall be 20 miles or another specified distance greater than 20 miles. (3) A requirement described in subsection (2) does not apply to a person if the person is married and both of the following conditions are met: (a) The person's spouse is employed by another public employer. (b) The person's spouse is subject to a condition of employment or promotion that, if not for this section, would require him or her to reside a distance of less than 20 miles from the nearest boundary of the public employer. (4) Subsection (1) does not apply if the person is a volunteer or paid on-call firefighter, an elected official, or an unpaid appointed official.