years. (3) Exclusion of gain on qualified gigabit opportunity zone property held for at least 10 years Except as provided in paragraph (2), in the case of the sale or exchange of qualified gigabit opportunity zone property, or an investment in a qualified opportunity fund, held for at least 10 years, gross income for the taxable year shall not include any gain from the sale or exchange of such property or investment. (4) One election per property No election may be made under paragraph (1) with respect to a sale or exchange if an election previously made with respect to such sale or exchange is in effect. (b) Basis rules relating to qualified gigabit opportunity zone property (1) Reduced by gain deferred under subsection (a)(1) The basis of a qualified gigabit opportunity zone property immediately after its acquisition under subsection (a) shall be reduced by the amount of gain deferred by reason of subsection (a)(1)(A) with respect to such property. (2) Increase for gain recognized under subsection (a)(2) The basis of qualified gigabit opportunity zone property shall be increased by the amount of gain recognized by reason of subsection (a)(2) with respect to such property. (3) Subsequent increase in basis for property held for at least 5 years but less than 10 years In the case of qualified gigabit opportunity zone property held for at least 5 years but less than 10 years— (A) Property held for 5 years For qualified gigabit opportunity zone property held for at least 5 years, the basis of such property shall be increased by an amount equal to 10 percent of the amount of gain deferred by reason of subsection (a)(1)(A) with respect to such property. (B) Property held for 7 years For qualified gigabit opportunity zone property held for at least 7 years, the basis of such property shall be increased by an amount equal to 5 percent of the amount of gain deferred by reason of subsection (a)(1)(A) with respect to such property. (c) Eligible taxpayer For purposes of this section, the term eligible taxpayer means any