taxable income (A) Exception from wage limit In the case of any taxpayer whose taxable income for the taxable year does not exceed the threshold amount, paragraph (2) shall be applied without regard to subparagraph (B). (B) Phase-in of limit for certain taxpayers (i) In general If— (I) the taxable income of a taxpayer for any taxable year exceeds the threshold amount, but does not exceed the sum of the threshold amount plus $50,000 ($100,000 in the case of a joint return), and (II) the amount determined under paragraph (2)(B) (determined without regard to this subparagraph) with respect to any qualified trade or business carried on by the taxpayer is less than the amount determined under paragraph (2)(A) with respect such trade or business, then paragraph (2) shall be applied with respect to such trade or business without regard to subparagraph (B) thereof and by reducing the amount determined under subparagraph (A) thereof by the amount determined under clause (ii). (ii) Amount of reduction The amount determined under this subparagraph is the amount which bears the same ratio to the excess amount as— (I) the amount by which the taxpayer's taxable income for the taxable year exceeds the threshold amount, bears to (II) $50,000 ($100,000 in the case of a joint return). (iii) Excess amount For purposes of clause (ii), the excess amount is the excess of— (I) the amount determined under paragraph (2)(A) (determined without regard to this paragraph), over (II) the amount determined under paragraph (2)(B) (determined without regard to this paragraph). (4) Wages, etc (A) In general The term W-2 wages means, with respect to any person for any taxable year of such person, the amounts described in paragraphs (3) and (8) of section 6051(a) paid by such person with respect to employment of employees by such person during the calendar year ending during such taxable year. (B) Limitation to wages attributable to qualified business income Such term shall not include any amount which is not properly allocable to qualified