; and (B) 12-month periods occurring before the 24-month period described in section 202(c)(1)(B) shall not be treated as years of service. For purposes of this paragraph, 12-month periods shall be determined in the same manner as under the last sentence of section 202(a)(3)(A), except that 12-month periods beginning before January 1, 2019, shall not be taken into account. . (c) Penalty Section 502 of the Employee Retirement Income Security Act of 1974 ( 29 U.S.C. 1132 ) is amended by adding at the end the following new subsection: (n) Requirements relating to part-Time employees In the case of a plan that fails to permit participation as required by section 202(c), the Secretary may assess a civil penalty against the plan sponsor in an amount equal to $10,000 per year per employee to whom such failure relates. The Secretary may, in the Secretary’s sole discretion, waive or reduce the penalty under this subsection if the Secretary determines that the plan sponsor acted reasonably and in good faith. . 5. Effective dates (a) Increasing spousal protection under defined contribution plans Except as provided in subsections (c) and (d), the amendments made by section 2 shall apply to distributions and rollover contributions made in plan years beginning after the date that is 6 months after the date of the enactment of this Act. (b) Ensuring coverage for long-Term part-Time workers Except as provided in subsections (c) and (d), the amendments made by section 3 shall apply to plan years beginning after December 31, 2018. (c) Collective bargaining agreements In the case of a plan maintained pursuant to one or more collective bargaining agreements between employee representatives and one or more employers ratified before the date of the enactment of this Act, the amendments made by sections 2 and 3 shall not apply to distributions or rollover contributions on behalf of employees covered by any such agreement for plan years beginning before the earlier of— (1) the later of— (A) the date on which the last of such collective