determined under section 1(f)(3) for the calendar year in which the taxable year begins, determined by substituting calendar year 2017 for calendar year 1992 in subparagraph (B) thereof. If any amount after adjustment under the preceding sentence is not a multiple of $100, such amount shall be rounded to the next lower multiple of $100. . (b) Excess contributions (1) In general Section 4973(a) of such Code is amended by striking or at the end of paragraph (5), by inserting or at the end of paragraph (6), and by inserting after paragraph (6) the following new paragraph: (7) a first-time homebuyer account (within the meaning of section 530A), . (2) Excess contributions Section 4973 of such Code is amended by adding at the end the following new subsection: (i) Excess contributions to first-Time homebuyer account In the case of a first-time homebuyer account, the term excess contributions means the amount by which the amount contributed for the taxable year to such account (other than contributions described in section 530A(d)(1)(C)(iv) and (v)) exceeds the contribution limits under section 530A(b). For purposes of the preceding sentence, any contribution which is distributed from the account in a distribution to which section 530A(d)(1)(C)(iii)(III) applies shall be treated as an amount not contributed. . (c) Clerical amendment The table of parts for subchapter F of chapter 1 of such Code is amended by adding at the end the following new item: Part IX. First-Time homebuyer accounts . (d) Effective date The amendments made by this section shall apply to taxable years beginning after the date of the enactment of this Act.