or (2) taxable income (determined without regard to this section and section 199) for the taxable year. (b) Limitation based on domestic investment For purposes of this section— (1) In general The amount of the deduction allowable under subsection (a) for any taxable year shall not exceed 25 percent of the taxpayer’s qualifying domestic investment for the taxable year. (2) Qualifying domestic investment amount The term qualifying domestic investment means, with respect to any taxpayer for any taxable year, the sum of— (A) the W–2 wages of such taxpayer for such taxable year, (B) the sum of the deductions allowable under sections 167, 169, 179, and 179D to such taxpayer for such taxable year, plus (C) the deduction allowable under section 174 to such taxpayer for such taxable year. (3) W– 2 wages The term W–2 wages means, with respect to any person for any taxable year, the sum of 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. Such term shall not include any amount which is not properly included in a return filed with the Social Security Administration on or before the 60th day after the due date (including extensions) for such return. (4) Limitation to amounts attributable to domestic production The term qualifying domestic investment shall not include any amount which is not properly allocable to domestic manufacturing gross receipts for purposes of subsection (c) (and shall include any amount which is so allocable under subsection (c)(4)). (5) Acquisitions and dispositions The Secretary shall provide for the application of this subsection in cases where the taxpayer acquires, or disposes of, the major portion of a trade or business or the major portion of a separate unit of a trade or business during the taxable year. (c) Domestic manufacturing income For purposes of this section— (1) In general The term domestic manufacturing income for any taxable year means