Aggregation rules For purposes of this subparagraph— (I) Family members Individuals who are spouses or who bear any of the relationships described in section 152(d)(2) to each other shall be treated as 1 taxpayer (without regard to whether spouses file a joint return). (II) Corporations and other entities All persons treated as a single employer under subsection (a) or (b) of section 52 or subsection (m) or (o) of section 414 shall be treated as 1 person. (iv) Adjustment for inflation In the case of exchanges completed in a taxable year beginning after December 31, 2017, the $1,000,000 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 calendar year 2016 for calendar year 1992 in subparagraph (B) thereof. If any amount as adjusted under the preceding sentence is not a multiple of $1,000, such amount shall be rounded to the nearest multiple of $1,000. . (b) Exclusion of art and collectibles Subparagraph (A) of section 1031(a)(2) of the Internal Revenue Code of 1986, as amended by subsection (a), is amended— (1) by striking or at the end of clause (v), (2) by striking the period at the end of clause (vi) and inserting , or , and (3) by inserting after clause (vi) the following new clause: (vii) any collectible (within the meaning of section 408(m), without regard to paragraph (3) thereof). . (c) Regulatory authority Subsection (f) of section 1031 of the Internal Revenue Code of 1986 is amended by adding at the end the following new paragraph: (5) Rules relating to dollar limitation The Secretary shall prescribe such guidance as is necessary for applying subsection (a)(2)(B)(i) in the case of the exchange of multiple pieces of real property by related persons. . (d) Conforming amendments (1) Subsection (b) of section 1031 of the Internal Revenue Code of 1986 is amended— (A) by striking in kind .—If an exchange and