of tracts contiguous with low-Income communities (1) In general A population census tract that is not a low-income community may be designated as a qualified opportunity zone under this section if— (A) the tract is contiguous with the low-income community that is designated as a qualified opportunity zone, and (B) the median family income of the tract does not exceed 125 percent of the median family income of the low-income community with which the tract is contiguous. (2) Limitation Not more than 5 percent of the population census tracts designated in a State as a qualified opportunity zone may be designated under paragraph (1). (g) Period for which designation is in effect A designation as a qualified opportunity zone shall remain in effect for the period beginning on the date of the designation and ending at the close of the 10th calendar year beginning on or after such date of designation. 1400Z–2. Special rules for capital gains invested in opportunity zones (a) In general In the case of gain from the sale to, or exchange with, an unrelated person of any property held by the taxpayer, at the election of the taxpayer— (1) gross income for the taxable year shall not include so much of such gain as does not exceed the aggregate amount invested by the taxpayer in a qualified opportunity fund during the 180-day period beginning on the date of such sale or exchange, (2) the amount of gain excluded by paragraph (1) shall be included in gross income as provided by subsection (b), and (3) subsection (c) shall apply. No election may be made under the preceding sentence with respect to a sale or exchange if an election previously made with respect to such sale or exchange is in effect. (b) Deferral of gain invested in opportunity zone property (1) Year of inclusion Gain to which subsection (a)(2) applies shall be included in income in the taxable year which includes the earlier of— (A) the date on which such investment is sold or exchanged, or (B) December 31, 2026. (2) Amount includible (A) In general The amount of