(b) Definitions.

1. (1) Tax normalization means computing the income tax component as if transactions recognized in each period for ratemaking purposes are also recognized in the same amount and in the same period for income tax purposes.
2. (2) Commission-approved ratemaking method means a ratemaking method approved by the Commission in a final decision. This includes a ratemaking method that is part of an approved settlement or arbitration providing that the ratemaking method is to be effective beyond the term of the settlement or arbitration.
3. (3) Income tax purposes means for the purpose of computing actual income tax under the provisions of the Internal Revenue Code or the income tax provisions of the laws of a State or political subdivision of a State (including franchise taxes).
4. (4) Income tax component means that part of the cost-of-service that covers income tax expenses allowable by the Commission.
5. (5) Ratemaking purposes means for the purpose of fixing, modifying, accepting, approving, disapproving, or rejecting rates under the Natural Gas Act.
6. (6) Tax effect means the tax reduction or addition associated with a specific expense or revenue transaction.
7. (7) Transaction means an activity or event that gives rise to an accounting entry.

(c) Reduction of, and addition to, Rate Base.

1. (1) The rate base of an interstate pipeline using tax normalization under this section must be reduced by the balances that are properly recordable in Account 281, “Accumulated deferred income taxes-accelerated amortization property”; Account 282, “Accumulated deferred income taxes—other property”: and Account 283, “Accumulated deferred income taxes—other.” Balances that are properly recordable in Account 190, “Accumulated deferred income taxes,” must be treated as an addition to rate base. Include, as an addition or reduction, as appropriate, amounts in Account 182.3, Other regulatory assets, and Account 254, Other regulatory liabilities, that result from a deficiency or excess in the deferred tax accounts (see paragraph (d) of this section) and which have been, or are soon expected to be, authorized for recovery or refund through rates.
2. (2) Such rate base reductions or additions must be limited to deferred taxes related to rate base, construction, or other costs and revenues affecting jurisdictional cost-of-service.

(d) Special rules.

1. (1) This paragraph applies:

   1. (i) If the rate applicant has not provided deferred taxes in the same amount that would have accrued had tax normalization always been applied; or
   2. (ii) If, as a result of changes in tax rates, the accumulated provision for deferred taxes becomes deficient in, or in excess of, amounts necessary to meet future tax liabilities.
2. (2) The interstate pipeline must compute the income tax component in its cost-of-service by making provision for any excess or deficiency in deferred taxes.
3. (3) The interstate pipeline must apply a Commission-approved ratemaking method made specifically applicable to the interstate pipeline for determining the cost-of-service provision described in paragraph (d)(2) of this section. If no Commission-approved ratemaking method has been made specifically applicable to the interstate pipeline, then the interstate pipeline must use some ratemaking method for making such provision, and the appropriateness of such method will be subject to case-by-case determination.
4. (4) An interstate pipeline must continue to include, as an addition or reduction to rate base, any deficiency or excess attributable to prior flow-through or changes in tax rates (paragraphs (d)(1)(i) and (d)(1)(ii) of this section), until such deficiency or excess is fully amortized in accordance with a Commission approved ratemaking method.