be substituting $10,500 (half such dollar amount for $5,000 ($2,500 . (ii) Inflation adjustment In the case of any taxable year beginning after 2021, the $10,500 amount in clause (i) shall be increased by an amount equal to— (I) such dollar amount, multiplied by (II) the cost-of-living adjustment determined under section 1(f)(3) for the calendar year in which the taxable year begins, determined by substituting 2020 for 2016 in subparagraph (A)(ii) thereof. Any increase determined under the preceding sentence which is not a multiple of $50, shall be rounded to the nearest multiple of $50. . (b) Effective date The amendment made by this section shall apply to taxable years beginning after December 31, 2020. E Net operating losses 241. Five-year carryback of net operating losses and temporary suspension of taxable income limitation (a) In general Section 172 of the Internal Revenue Code of 1986 is amended by redesignating subsection (g) as subsection (h) and by inserting after subsection (f) the following new subsection: (g) Special rules for 2018, 2019, and 2020 For purposes of this section— (1) Five-year carryback (A) In general Any net operating loss arising in a taxable year beginning after December 31, 2017, and before January 1, 2021— (i) shall be a net operating loss carryback to each of the 5 taxable years preceding the taxable year of such loss (but not to any taxable year beginning before January 1, 2015), and (ii) subparagraphs (B) and (C)(i) of subsection (b)(1) shall not apply. (B) Election out A taxpayer may elect not to have subparagraph (A) apply for any taxable year. Such election shall be made in such manner as may be prescribed by the Secretary, and shall be made— (i) in the case of any election relating to a net operating loss arising in a taxable 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