applicable tax limit
(1) Carryforward of unused credit (A) In general If the credit allowable under subsection (a) for any taxable year exceeds the applicable tax limit for such taxable year, such excess shall be a carryover to each of the 3 succeeding taxable years and, subject to the limitations of subparagraph (B), shall be added to the credit allowable by subsection (a) for such succeeding taxable year. (B) Limitation The amount of the unused credit which may be taken into account under subparagraph (A) for any taxable year shall not exceed the amount (if any) by which the applicable tax limit for such taxable year exceeds the sum of— (i) the credit allowable under subsection (a) for such taxable year determined without regard to this paragraph, and (ii) the amounts which, by reason of this paragraph, are carried to such taxable year and are attributable to taxable years before the unused credit year. (C) Applicable tax limit For purposes of this paragraph, the term “applicable tax limit” means the limitation imposed by section 26(a) for the taxable year reduced by the sum of the credits allowable under this subpart (other than this section and sections 23 and 25D).