IV Defined benefit plan reforms 401. Cash balance (a) In general Section 414 of the Internal Revenue Code of 1986, as amended by this Act, is amended by adding at the end the following new subsection: (bb) Projected interest crediting rate For purposes of this part, in the case of an applicable defined benefit plan that provides variable interest crediting rates, the interest crediting rate that is treated as in effect and as the projected interest crediting rate shall be a reasonable projection of such variable interest crediting rate, subject to a maximum of 6 percent. . (b) Effective date The amendments made by this section shall apply with respect to years beginning after the date of enactment of this Act. 402. Aligning use of lookback months to determine interest rates The Secretary of the Treasury shall modify Treasury Regulation section 1.417(e)–1(d)(10)(ii) (or any successor provision) to provide that the same rule applicable to modifications of the time for determining the applicable interest rate shall apply to modifications of the time for determining any interest rate used by a plan to the extent that the use of such interest rate is permissible under section 417(e)(3) of the Internal Revenue Code of 1986, provided that the regulations shall require that after any such modification of such time under a plan pursuant to this section, no further modifications of such time are to be permitted for five years with respect to such plan without the consent of the Secretary of the Treasury. As of the date of enactment of this Act, such regulation (or any successor provision) shall be deemed to be amended in such manner, so that this change in the regulations is deemed to have occurred. 403. Aligning employer pension contribution due date with corporate return due date (a) In general Paragraph (1) of section 430(j) of the Internal Revenue Code of 1986 is amended by striking 8 1/2 and inserting 9 1/2 . (b) Effective date The amendment made by this section shall apply to payments made after the date of