26 U.S.C. § 3211: Rate of tax

In addition to other taxes, there is hereby imposed on the income of each employee representative a tax equal to the applicable percentage of the compensation received during any calendar year by such employee representative for services rendered by such employee representative. For purposes of the preceding sentence, the term “applicable percentage” means the percentage equal to the sum of the rates of tax in effect under subsections (a) and (b) of section 3101 and subsections (a) and (b) of section 3111 for the calendar year. In addition to other taxes, there is hereby imposed on the income of each employee representative a tax equal to the percentage determined under section 3241 for any calendar year of the compensation received during such calendar year by such employee representative for services rendered by such employee representative. For application of different contribution bases with respect to the taxes imposed by subsections (a) and (b), see section 3231(e)(2).