taxable year shall be increased by the amount of credit determined for the taxable year under section 41(a)(4) (as added by this section). (2) Taxable years beginning after December 31, 2020 Section 280C(c)(1) of such Code is amended by striking section 41(a)(1) and inserting paragraphs (1) and (4) of section 41(a) . (d) Conforming amendment Section 41(f)(1) of such Code is amended by striking and amounts paid or incurred to energy research consortiums each place it appears and inserting , amounts paid or incurred to energy research consortiums, and specified medical research expenditures . (e) Effective date The amendments made by this section shall apply to amounts paid or incurred after the date of the enactment of this Act, in taxable years ending after such date. 8004. Refundable portion of research credit for small businesses engaging in specified medical research (a) In general Section 41 of the Internal Revenue Code of 1986 is amended by adding at the end the following new subsection: (i) Refundable portion for small businesses engaging in specified medical research (1) In general At the election of a medical research small business, the portion of the credit determined under this section for the taxable year which is properly allocable to specified medical research shall be treated (other than for purposes of section 280C) as a credit allowed under subpart C (and not this subpart). (2) Medical research small business For purposes of this subsection, the term medical research small business means any domestic C corporation— (A) which conducts any specified medical research during the taxable year, and (B) the gross receipts of which (determined under the rules of subsection (c)) for the taxable year do not exceed $1,000,000. (3) Specified medical research For purposes of this subsection, the term specified medical research means any qualified research with respect to qualified countermeasures (as defined in section 319F–1(a)(2) of the Public Health Service Act (42 U.S.C. 247d–6a(a)(2))). (4) Election Any