such section 802 for the taxable year or any of the 4 taxable years preceding such year. . (d) Effective date The amendments made by this section shall apply to taxable years beginning after the date of the enactment of this Act. 5. Credit for minimum employer contributions (a) In general Subpart D of part IV of subchapter A of chapter 1 of the Internal Revenue Code of 1986 is amended by adding at the end the following new section: 45T. Credit for minimum employer contributions (a) General rule For purposes of section 38, the minimum employer contribution credit determined under this section for any taxable year is an amount equal to the applicable percentage of the qualified retirement contributions paid or incurred by the taxpayer during the taxable year. (b) Applicable percentage For purposes of subsection (a), the applicable percentage is— (1) 50 percent, in the case of contributions made with respect to not more than 15 employees of the employer (or the number of employees of the employer which is the equivalent of 15 full-time employees), and (2) 25 percent, in the case of contributions made with respect to so many of the employees of the employer (or the equivalent of so many full-time employees) as exceeds 15 but does not exceed 30. (c) Qualified retirement contributions For purposes of this section— (1) In general The term qualified retirement contributions means— (A) contributions made by an employer as required under section 802 of the Employee Retirement Income Security Act of 1974, and (B) contributions to a plan described in section 802(b)(2) of such Act made by an employer which is not subject to the requirement of section 802(a)(1) of such Act. (2) Only required contribution amount taken into account The term qualified retirement contributions does not include any amount in excess of— (A) the amount determined under section 802(a)(2) of the Employee Retirement Income Security Act with respect to each employee of the employer, or (B) the amount which would be so determined if the employer were