1. Short title This Act may be cited as the Research and Development Tax Credit Expansion Act of 2019 . 2. Expansion of refundable research credit for new and small businesses (a) Doubling cap on refundable credit (1) In general Clause (i) of section 41(h)(4)(B) of the Internal Revenue Code of 1986 is amended by striking $250,000 and inserting $500,000 . (2) Adjustment for inflation Paragraph (4) of section 41(h) of such Code is amended— (A) by redesignating subparagraph (C) as subparagraph (D), (B) by redesignating clause (ii) of subparagraph (B) as subparagraph (C), and by moving such subparagraph 2 ems to the left, (C) by striking Limitations in the heading of subparagraph (B) and inserting Limitation on amount of election , (D) by striking Amount in the heading of clause (i) of subparagraph (B) and inserting In general , and (E) by adding at the end of subparagraph (B), as amended by the preceding subparagraphs of this paragraph, the following new clause: (ii) Adjustment for inflation In the case of a taxable year beginning after 2020, the $500,000 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 2019 for 2016 in subparagraph (A)(ii) thereof. If any increase under the preceding sentence is not a multiple of $100, such increase shall be rounded to the nearest multiple of $100. . (3) Conforming amendment Clause (ii) of section 41(h)(5)(B) of such Code is amended by striking the $250,000 amount and inserting the amount in effect . (b) Credit refundable against Medicare and unemployment taxes (1) In general Paragraph (1) of section 3111(f) of the Internal Revenue Code of 1986 is amended by striking subsection (a) and inserting subsections (a) and (b) and section 3301 . (2) Conforming amendments (A) Paragraph (2) of section 3111(f) of such Code is amended by striking the tax imposed by subsection (a) and inserting