On January 11, 2011, the U.S. Supreme Court issued a unanimous ruling that medical residents, those engaged in paid employment of 40 or more hours per week, must pay Federal payroll taxes and are not considered “students” under IRS regulations for purposes of payroll tax exemption.  The suit, brought by the Mayo Clinic and the University of Minnesota, sought to recover payroll taxes previously withheld from residents employed at both facilities.  Chief Justice John Roberts wrote, “We do not doubt that Mayo’s residents are engaged in a valuable educational pursuit or that they are students of their craft.  The question is whether they are ‘students’ for purposes of [the federal statute] … Because it is one to which Congress has not directly spoken, and because the Treasury Department’s rule is a reasonable construction of what Congress has said, the judgment of the court of appeals [to require payroll tax withholdings] must be affirmed.”