plan maintained by the eligible employer, or (ii) $5,000, and . (c) Effective date The amendments made by this section shall apply to taxable years beginning after December 31, 2018. 112. Credit for re-enrollment (a) In general Subpart D of part IV of subchapter A of chapter 1, as amended by this Act, is further amended by adding at the end the following new section: 45U. Credit for re-enrollment provisions in plans provided by small employers (a) In general For purposes of section 38, in the case of an eligible employer, the retirement re-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 a re-enrollment provision in 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 provision 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). (d) Re-Enrollment provision For purposes of this section, the term re-enrollment provision means a provision of an eligible automatic contribution arrangement under which— (1) In general Each employee eligible to participate in the arrangement who is not contributing or is contributing less than the percentage applicable to an eligible employee in the first year of eligibility is treated as being in such first year of eligibility in each applicable year with respect to the employee. (2) Election out The election treated as