Mich. Comp. Laws § 380.1407: “High school” defined.

Sec. 1407.

A high school approved for the collection of high school tuition shall be a school district operating grades above the eighth grade having 1 of the following:

Twelve grades with at least 3 teachers devoting their entire teaching time to the work of the seventh to twelfth grades.

Twelve grades with at least 2 teachers devoting their entire teaching time to the work of the ninth to twelfth grades.

Nine grades with at least 1 teacher devoting the teacher's entire teaching time to the work of the seventh to ninth grades.

Ten grades with at least 1 teacher devoting the teacher's entire teaching time to the work of the ninth and tenth grades, or the eighth to tenth grades.

Eleven grades with at least 2 teachers devoting their teaching time to the work of the ninth to eleventh grades, or the eighth to eleventh grades.