be a determined in accordance with section 143(f)(2) and 143(f)(4). (D) Timing For purposes of this paragraph, the income of a taxpayer shall be determined— (i) in the case of a residence that is built or substantially rehabilitated as part of a qualified project and sold, at the time a binding contract for purchase is made, or (ii) in the case of a residence that is occupied by a qualified homeowner and intended to be substantially rehabilitated as part of a qualified project, at the time a binding contract to undertake such rehabilitation is made. (7) Neighborhood homes credit agency The term neighborhood homes credit agency means the agency designated by the governor of a State as the neighborhood homes credit agency of the State. (g) Allocation (1) State neighborhood homes credit ceiling The State neighborhood homes credit amount for a State for a calendar year is an amount equal to the sum of— (A) the greater of— (i) the product of $3, multiplied by the State population (determined in accordance with section 146(j)), or (ii) $4,000,000, plus (B) the converted private activity bond amount with respect to the State for the calendar year. (2) Unused amount The State neighborhood homes credit amount for a calendar year shall be increased by the sum of— (A) any amount certified by the neighborhood homes credit agency of the State as having been previously allocated to a qualified project and not used during the 5-year period described in subsection (b)(2)(iii), plus (B) sum of the amount by which the amount determined under paragraph (1) (without application of this paragraph) exceeded the amount allocated to qualified projects in each of the three immediately preceding calendar years. (3) Converted private activity bond amount (A) In general For purposes of this paragraph, the converted private activity bond amount with respect to any State for any calendar year shall be 60 percent of the amount elected by— (i) the State agency that is an issuer of qualified mortgage bonds (as defined in section 143) that is