Wis. Admin. Code DWD § 290.05
All hours worked by a laborer, worker, mechanic or truck driver in excess of the prevailing hours of labor per day or per week must be paid at a rate at least 1.5 times the hourly basic rate of pay. Sums paid by an employer for bona fide economic benefits shall be excluded in the computation of the overtime premium. In no event can the rate upon which the overtime premium is calculated be less than the amount determined by the department as the hourly basic rate of pay. Nor can the rate upon which the overtime premium is calculated be less than the straight time cash payment made to the laborer, worker, mechanic or truck driver or be less than the employee's normal hourly basic rate of pay, if it is higher. Contributions by employees are not excluded from the rate upon which the overtime premium is computed; that is, an employee's overtime premium rate is computed on the taxable earnings before any deductions are made for the employee's contributions to bona fide economic benefits. The employer's contributions, costs or cash payments for bona fide economic benefits may be excluded in computing the overtime premium rate so long as the exclusions do not reduce the overtime premium rate below the hourly basic rate contained in the prevailing wage rate determination issued for a project.
Wis. Admin. Code Department of Workforce Development § DWD 290.05