Mich. Comp. Laws § 500.3402d

Sec. 3402d. (1) For purposes of this chapter, blanket disability insurance is disability insurance that covers special groups of individuals, as follows: (a) A policy issued to a common carrier as the policyholder and that covers a group defined as all individuals who are passengers of the common carrier. (b) A policy issued to an employer as the policyholder and that covers all employees or any group of employees defined by reference to exceptional hazards incidental to the employment. (c) A policy issued to a university, college, school, or other educational institution, or to the head or principal of the university, college, school, or institution as the policyholder, that covers students or teachers. (d) A policy issued to a volunteer fire department, first aid group, or other volunteer group as the policyholder that covers all of the members of the department or group. (e) A policy issued to a creditor as the policyholder that insures debtors of the creditor. (f) A policy issued to a sports team or camp as the policyholder that covers members or campers. (2) In the discretion of the director, blanket disability insurance may be issued to any other special group of individuals that is substantially similar to a group described in subsection (1).