Mich. Comp. Laws § 339.6117a

Sec. 1117a. (1) The ratio of journey plumbers or master plumbers who provide direct, on-site, in-person supervision as required under section 1117 to an apprentice is on the basis of 1 journey plumber or master plumber to not more than 2 apprentices. The department or an enforcing agency shall enforce the ratio on a jobsite basis. (2) If a plumbing contractor violates this section, the plumbing contractor is subject to the following punishments: (a) For a first violation, a $5,000.00 administrative fine. (b) For a second violation, a $10,000.00 administrative fine. (c) For a third violation, a suspension, for not less than 90 days, of the plumbing contractor's plumbing contractor license. After 90 days, the plumbing contractor may have the license reinstated if the plumbing contractor passes the plumbing contractor examination described in section 1111. (3) The department shall pay any money collected under this section for an administrative fine to the enforcing agency that discovered the violation that resulted in the administrative fine. (4) If the department issues an order for a violation of this section, the department is entitled to actual costs and attorney fees related to the investigation and adjudication of the violation.