; and (II) such plan or contract amendment applies retroactively for such period. (c) Special rules for personal casualty losses related to Louisiana severe storms and flooding (1) In general If an individual has a net disaster loss for any taxable year beginning after December 31, 2017, and before January 1, 2026— (A) the amount determined under section 165(h)(2)(A)(ii) of the Internal Revenue Code of 1986 shall be equal to the sum of— (i) such net disaster loss, and (ii) so much of the excess referred to in the matter preceding clause (i) of section 165(h)(2)(A) of such Code (reduced by the amount in clause (i) of this subparagraph) as exceeds 10 percent of the adjusted gross income of the individual, (B) section 165(h)(1) of such Code shall be applied by substituting $500 for $500 ($100 for taxable years beginning after December 31, 2009) , (C) the standard deduction determined under section 63(c) of such Code shall be increased by the net disaster loss, and (D) section 56(b)(1)(E) of such Code shall not apply to so much of the standard deduction as is attributable to the increase under subparagraph (C) of this paragraph. (2) Net disaster loss For purposes of this subsection, the term net disaster loss means the excess of qualified disaster-related personal casualty losses over personal casualty gains (as defined in section 165(h)(3)(A) of the Internal Revenue Code of 1986). (3) Qualified disaster-related personal casualty losses For purposes of this paragraph, the term qualified disaster-related personal casualty losses means losses described in section 165(c)(3) of the Internal Revenue Code of 1986 which arise— (A) in the portion of the Mississippi River Delta flood disaster area described in subsection (a)(1) on or after August 11, 2016, and which are attributable to the severe storms and flooding giving rise to the Presidential declaration described in subsection (a)(1), or (B) in the portion of the Mississippi River Delta flood disaster area described in subsection (a)(2) on or after March 1, 2016, and