described in subsection (d)(2). (f) Married couples must file joint returns Rules similar to the rules of paragraphs (2), (3), and (4) of section 21(e) shall apply for purposes of this section. . (b) Conforming amendments (1) The table of sections for subpart A of part IV of subchapter A of chapter 1 of the Internal Revenue Code of 1986 is amended by inserting before the item relating to section 24 the following new item: Sec. 23A. Credit for certain infertility treatments. . (2) Section 23(c)(1) of such Code is amended by striking 25D and inserting 23A, 25D, . (3) Section 25(e)(1)(C) of such Code is amended by inserting 23A, before 25D, . (4) Section 25D(c) of such Code is amended by inserting and section 23A after other than this section . (5) Section 1400C(d) of such Code is amended by striking section 25D and inserting sections 23A and 25D . (c) Effective date The amendments made by this section shall apply to taxable years beginning after the date of the enactment of this Act.