member means the youngest individual who— (I) is taken into account in determining the applicable taxpayer's family size under subsection (d)(1) and is covered under the qualified health plan, and (II) has attained 18 years of age but not attained 35 years of age as of the close of the taxable year. (iv) Rounding Any reduction determined under clause (i) shall be rounded to the nearest 1/10th of 1 percentage point. . (b) Effective date The amendment made by this section shall apply to taxable years beginning after the date of the enactment of this Act.