under section 481(a) shall be made. . (c) Effective date The amendment made by this section shall apply to contracts entered into after December 31, 2017, in taxable years ending after such date. III Modifications of expensing and cost recovery rules A Expensing rules 301. Modifications of rules for expensing depreciable business assets (a) Increase in limitation (1) Dollar limitation Section 179(b)(1) by striking $500,000 and inserting $2,000,000 . (2) Reduction in limitation Section 179(b)(2) is amended by striking $2,000,000 and inserting $3,000,000 . (3) Inflation adjustments (A) In general Subparagraph (A) of section 179(b)(6) is amended— (i) by striking 2015 and inserting 2018 , and (ii) by striking calendar year 2014 in clause (ii) and inserting calendar year 2017 . (B) Sport utility vehicles Section 179(b)(6) is amended— (i) by striking paragraphs (1) and (2) in subparagraph (A) and inserting paragraphs (1), (2), and (5)(A) , and (ii) by inserting (($100 in the case of any increase in the amount under paragraph (5)(A)) after $10,000 in subparagraph (B). (b) Section 179 property To include qualified real property (1) In general Subparagraph (B) of section 179(d)(1) is amended to read as follows: (B) which is— (i) section 1245 property (as defined in section 1245(a)(3)), or (ii) qualified real property (as defined in subsection (f)), and . (2) Qualified real property defined Section 179(f) is amended to read as follows: (f) Qualified real property For purposes of this subsection, the term qualified real property means— (1) any qualified improvement property described in section 168(k)(3), and (2) any of the following improvements to nonresidential real property placed in service after the date such property was first placed in service: (A) Roofs. (B) Heating, ventilation, and air-conditioning property. (C) Fire protection and alarm systems. (D) Security systems. . (c) Repeal of exclusion for certain property The last sentence of section 179(d)(1) is amended by inserting (other than paragraph (2) thereof)