20 percent for 14 percent . (ii) Special rule for 1st year of qualified research expenses If the taxpayer has no qualified research expenses in any taxable year preceding the taxable year for which the credit is being determined, subparagraph (B)(ii) shall be applied by substituting 20 percent for 6 percent . (iii) Special rule for other years If the taxpayer is not described in clause (ii) for the taxable year, and subparagraph (B) applies to such taxpayer for such year, at the election of the taxpayer— (I) subparagraph (B)(ii) shall be applied by substituting 10 percent for 6 percent , or (II) subparagraph (B) shall not apply, and the average under subparagraph (A) shall be determined by disregarding any taxable year in the 3-year period described in such subparagraph in which there were no qualified research expenses. . (b) Effective date The amendment made by this section shall apply to taxable years beginning after December 31, 2023.