(1) Section 1 of the Internal Revenue Code of 1986 is amended by striking subsections (i) and (j). (2) Section 3402(q)(1) of such Code is amended by striking third lowest and inserting fourth lowest . (j) Section 15 not To apply Section 15 of the Internal Revenue Code of 1986 shall not apply to any change in a rate of tax by reason of this section. (k) Effective date The amendments made by this section shall apply to taxable years beginning after December 31, 2018. 2. Permanent extension of deduction for qualified business income of pass-thru entities (a) In general Section 199A of the Internal Revenue Code of 1986 is amended by striking subsection (i). (b) Effective date The amendment made by this section shall apply to taxable years beginning after December 31, 2017. 3. Permanent extension of limitation on losses for taxpayers other than corporations (a) In general Paragraph (1) of section 461(l) of the Internal Revenue Code of 1986 is amended to read as follows: (1) Limitation In the case of taxable year of a taxpayer other than a corporation, any excess business loss of the taxpayer for the taxable year shall not be allowed. . (b) Conforming amendment Section 461 of the Internal Revenue Code of 1986 is amended by striking subsection (j) (relating to limitation on excess farm losses of certain taxpayers). (c) Effective date The amendments made by this section shall apply to taxable years beginning after December 31, 2017. 4. Permanent extension of increase in standard deduction (a) In general Section 63(c)(2) of the Internal Revenue Code of 1986 is amended— (1) by striking $4,400 in subparagraph (B) and inserting $18,800 , and (2) by striking $3,000 in subparagraph (C) and inserting $12,000 . (b) Inflation adjustment Paragraph (4) of section 63(c) of the Internal Revenue Code of 1986 is amended to read as follows: (4) Adjustments for inflation (A) In general In the case of any taxable year beginning in a calendar year after 2018, the $18,000 and $12,000 amounts in subparagraph (A) shall each be increased by