of payments made by the taxpayer during the prepayment period. (B) Prepayment period (i) In general For purposes of this paragraph, the term prepayment period means the period of 3 taxable years subsequent to the taxable year in which the credit under subsection (a) is allowed. (ii) Development of prepayment mechanism For purposes of subparagraph (A)(ii), the Secretary shall establish appropriate procedures and mechanisms to allow taxpayers to reduce the amount of the tax imposed under paragraph (1) by making payments during the prepayment period. (3) Recapture period For purposes of this subsection, the term recapture period means the period of 5 taxable years subsequent to the prepayment period. (4) Return requirement If the tax imposed by this chapter for the taxable year is increased under this subsection, the taxpayer shall, notwithstanding section 6012, be required to file a return with respect to the taxes imposed under this subtitle. (5) Joint returns In the case of a credit allowed under subsection (a) with respect to a joint return, half of such credit shall be treated as having been allowed to each individual filing such return for purposes of this subsection. (6) Exception This subsection shall not apply to any taxable year ending after the date of the death of the individual allowed the credit under subsection (a). (g) Definitions In this section: (1) Child The term child means a biological or legally adopted child who has not attained 18 years of age. (2) Parent The term parent means— (A) the biological mother or father of a child, or (B) an individual who legally adopts a child, who is the legal guardian of the child and who intends to maintain the same principal place of abode as the child for more than ½ of the 12-month period following the date of the birth or adoption of the child. (3) Parental leave The term parental leave means any period of leave from employment which is taken by a parent to provide care for a child. . (b) Pre-Calculation of parental leave credit Not later than January 1,