applicable percentage
In addition to other taxes, there is hereby imposed on every employer an excise tax, with respect to having individuals in his employ, equal to the applicable percentage of compensation paid during any calendar year by such employer for services rendered to such employer. 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 3111 for the calendar year.
Source
26 USC § 3221(a)
Scoping language
None identified, default scope is assumed to be the parent (subchapter C) of this section.