the correction window, a shortfall of distributions from an individual retirement plan which resulted in imposition of a tax under subsection (a), and (B) submits a return, during the correction window, reflecting such tax (modified by this subsection), the first sentence of subsection (a) shall be applied by substituting 10 percent for 50 percent . (2) Correction window For purposes of this subsection, the term correction window means the period of time beginning on the data on which the tax under subsection (a) is imposed with respect to a shortfall of distributions from an individual retirement plan, and ending on the earlier of— (A) the date on which the Secretary initiates an audit, or otherwise demands payment, with respect to the shortfall of distributions, or (B) the last day of the second taxable year that begins after the end of the taxable year in which the tax under subsection (a) is imposed. . 4. Harmonization of treatment of IRAs with employer plans (a) Elimination of additional tax on certain distributions Section 72(t)(2)(A) of the Internal Revenue Code of 1986 is amended— (1) by striking or at the end of clause (vii)