applicable percentage
In addition to other taxes, there is hereby imposed on the income of each employee a tax equal to the applicable percentage of the compensation received during any calendar year by such employee for services rendered by such employee. 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 for the calendar year.
Source
26 USC § 3201(a)
Scoping language
None identified, default scope is assumed to be the parent (subchapter A) of this section.