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 election under this subsection for any taxable year— (A) shall specify the amount of the credit to which such election applies, (B) shall be made on or before the due date (including extensions) of the return of tax for the taxable year, (C) may not be made for any taxable year with respect to any portion of the credit determined under this section with respect to which an election is made under subsection (h), and (D) may be revoked only with the consent of the Secretary. (5) Regulations The Secretary shall prescribe such regulations for purposes of this subsection as may be necessary or appropriate for determining proper allocation to specified medical research of the portion of any credit allowed to a taxpayer for a taxable year under this section. . (b) Conforming amendment Section 1324(b) of title 31, United States Code, is amended by inserting 41(i), after 6428, . (c) Effective date The amendments made by this section shall apply to taxable years beginning after December 31, 2020. 8005. Exception from passive loss rules for investments in specified medical research small business pass-thru entities (a) In general Subsection (c) of section 469 of the Internal Revenue Code of 1986 is amended by redesignating paragraphs (4) through (7) as paragraphs (5) through (8), respectively, and by inserting after paragraph (3) the following new paragraph: (4) Specified medical research activities (A) In general The term passive activity shall not include any qualified medical research activity of the taxpayer carried on by a specified medical research small business pass-thru entity. (B) Treatment of losses and deductions (i) In general Losses or deductions of a taxpayer in connection with qualified medical research activities carried on by a specified medical research