and (ii) nothing in this subsection shall be construed to affect the amount of any minimum required distribution determined without regard to this subsection or the plan or plans from which it is required to be distributed from. (B) Allocation of increase in minimum required distributions The taxpayer may, in such form and manner as the Secretary may prescribe, allocate any increase in minimum required distributions by reason of this subsection to applicable retirement plans treated as 1 plan under subparagraph (A) in such manner as the taxpayer chooses. (4) Treatment of Roth IRAs (A) In general Notwithstanding section 408A(c)(5)— (i) the aggregate balance to the credit of a payee of any Roth IRA shall be taken into account for purposes of this subsection, and (ii) distributions from a Roth IRA may be taken into account in determining whether the required increase in minimum required distributions by reason of this subsection has been satisfied. (B) Inclusion in income of distributed earnings If any distribution from a Roth IRA is taken into account under subparagraph (A)(ii), then, notwithstanding section 408A(d)(5), the portion of such distribution which is properly allocable to net income on contributions to the Roth IRA shall not be treated as a qualified distribution and shall be included in gross income of the payee. (5) Phase-in for taxpayers with excess balances for taxable year beginning in 2019 (A) In general If there is an excess described in paragraph (2)(A) for the first taxable year of a taxpayer beginning during 2019 (in this paragraph referred to as the historic excess ), then the amount taken into account under paragraph (1)(B)(i) for such first taxable year and each subsequent taxable year to which this paragraph applies shall, in lieu of the excess described in paragraph (2)(A) for each such taxable year, be equal to— (i) in the case of such first taxable year, 10 percent of the historic excess, and (ii) in the case of each subsequent taxable year to which this paragraph applies, the sum of—