Section 54.4975-1 - General rules relating to excise tax on prohibited transactions(a)Scope. This section provides general rules for the imposition of the excise taxes on prohibited transactions.(b)Initial tax. Section 4975(a) imposes an initial tax on each prohibited transaction. The initial tax is 5 percent of the amount involved with respect to the prohibited transaction for each year (or part thereof) in the taxable period.(c)Additional tax. Section 4975(b) imposes an excise tax in any case in which an initial tax is imposed under section 4975(a) on a prohibited transaction and the prohibited transaction is not corrected within the taxable period (as defined in paragraph (d) of this section). The additional tax is 100 percent of the amount involved with respect to the prohibited transaction.(d)Taxable period - (1)In general. For purposes of any prohibited transaction, the term "taxable period" means the period beginning with the date on which the prohibited transaction occurs and ending on the earliest of:(i) The date of mailing of a notice of deficiency under section 6212 with respect to the tax imposed by section 4975(a);(ii) The date on which correction of the prohibited transaction is completed; or(iii) The date on which the tax imposed by section 4975(a) is assessed.(2)Special rule. Where a notice of deficiency referred to in paragraph (d)(1)(i) of this section is not mailed because a waiver of the restrictions on assessment and collection of a deficiency has been accepted or because the deficiency is paid, the date of filing of the waiver or the date of such payment, respectively, shall be treated as the end of the taxable period.T.D. 8084, 51 FR 16305, May 2, 1986