who is not a highly compensated employee (as defined in section 414(q)) and who is eligible to participate in the eligible employer plan maintained by the eligible employer, or (ii) $5,000, and . (b) Effective date The amendment made by this section shall apply to taxable years beginning after December 31, 2018. 106. Small employer automatic enrollment credit (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: 45S. Auto-enrollment option for retirement savings options provided by small employers (a) In general For purposes of section 38, in the case of an eligible employer, the retirement auto-enrollment credit determined under this section for any taxable year is an amount equal to— (1) $500 for any taxable year occurring during the credit period, and (2) zero for any other taxable year. (b) Credit period For purposes of subsection (a)— (1) In general The credit period with respect to any eligible employer is the 3-taxable-year period beginning with the first taxable year for which the employer includes an eligible automatic contribution arrangement (as defined in section 414(w)(3)) in a qualified employer plan (as defined in section 4972(d)) sponsored by the employer. (2) Maintenance of arrangement No taxable year with respect to an employer shall be treated as occurring within the credit period unless the arrangement described in paragraph (1) is included in the plan for such year. (c) Eligible employer For purposes of this section, the term eligible employer has the meaning given such term in section 408(p)(2)(C)(i). . (b) Credit To be part of general business credit Subsection (b) of section 38 of the Internal Revenue Code of 1986 is amended by striking plus at the end of paragraph (35), by striking the period at the end of paragraph (36) and inserting , plus , and by adding at the end the following new paragraph: (37) in the case of an eligible employer (as defined in section 45S(c)), the retirement