year beginning in 2018 or 2019, by the due date (including extension of time) for filing the return for the taxpayer’s first taxable year ending after the date of the enactment of this subparagraph. (ii) in the case of any election relating to a net operating loss arising in a taxable year beginning in 2020, by the due date (including extensions of time) for such taxable year. Any such election, once made, shall be irrevocable. (2) Suspension of net operating loss limitation For taxable years beginning after December 31, 2017, and before January 1, 2021, the amount of the deduction allowed under subsection (a) shall be the aggregate of the net operating loss carryovers to such year, plus the net operating loss carrybacks to such year. (3) Disqualified taxpayer Paragraphs (1) and (2) shall not apply with respect to any taxable year in which the taxpayer is a disqualified taxpayer. Any taxpayer who is a disqualified taxpayer in the first taxable year ending after the date of the enactment of this paragraph, shall be treated as a disqualified taxpayer for taxable years beginning on or after January 1, 2018. (4) Definitions For purposes of this subsection— (A) Disqualified taxpayer A taxpayer is a disqualified taxpayer with respect to a taxable year if— (i) in the case of a taxable year ending after December 31, 2019, and beginning before January 1, 2021, the taxpayer (or any related person) is not allowed a deduction under this chapter for the taxable year by reason of section 162(m) or section 280G, or (ii) the taxpayer (or any related person) is a specified corporation for the taxable year. (B) Specified corporation (i) In general The term specified corporation means, with respect to any taxable year, a corporation the aggregate distributions (including redemptions) of which during any taxable year ending after December 31, 2017, exceed the sum of applicable stock issued of such corporation and 5 percent of the fair market value of the stock of such corporation as of the last day of the taxable year. (ii)