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 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, by substituting 2017 for 2016 in subparagraph (A)(ii) thereof. (B) Certain amounts In the case of any taxable year beginning in a calendar year after 1988, each dollar amount contained in paragraph (5) or subsection (f) 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, by substituting for calendar year 2016 in subparagraph (A)(ii) thereof— (I) calendar year 1987 in the case of the dollar amounts contained in paragraph (5)(A) or subsection (f), and (II) calendar year 1997 in the case of the dollar amount contained in paragraph (5)(B). . (c) Conforming amendment Section 63(c) of the Internal Revenue Code of 1986 is amended by striking paragraph (7). (d) Effective date The amendments made by this section shall apply to taxable years beginning after December 31, 2017. 5. Permanent increase and modification of child tax credit (a) Increase in credit amount Section 24(a) of the Internal Revenue Code of 1986 is amended by striking $1,000 and inserting $2,000 . (b) Limitation Paragraph (2) of section 24(b) of the Internal Revenue Code of 1986 is amended to read as follows: (2) Threshold amount For purposes of paragraph (1), the term threshold amount means— (A) $400,000 in the case of a joint return, and (B) $200,000 in any other case. . (c) Partial credit allowed for certain other dependents Subsection (h) of section 24 of the Internal Revenue Code of 1986 is amended to read as follows: (h) Partial credit allowed for certain other dependents (1)