§ 3321. Imposition of tax
(a)
General rule
There is hereby imposed on every rail employer for each calendar month an excise tax, with respect to having individuals in his employ, equal to 4 percent of the total rail wages paid by him during such month.
(b)
Tax on employee representatives
(c)
Termination if loans to railroad unemployment fund repaid
The tax imposed by this section shall not apply to rail wages paid on or after the 1st day of any calendar month if, as of such 1st day, there is—