; and (ii) by the close of which the employee has attained the age of 21. (2) Exception Paragraph (1)(B) shall not apply to employees who are included in a unit of employees covered by an agreement which the Secretary finds to be a collective bargaining agreement between employee representatives and 1 or more employers, if there is evidence that retirement benefits were the subject of good faith bargaining between such employee representatives and such employer or employers. (3) Coordination with other rules In the case of employees who are not highly compensated employees (within the meaning of section 414(q) of the Internal Revenue Code of 1986) and who are eligible to participate in the arrangement or agreement solely by reason of paragraph (1)(B): (A) Exclusions An employer may elect to exclude such employees from the determination of whether the plan that includes the arrangement or agreement satisfies the requirements of subsections (a)(4), (k)(3), (k)(12), (k)(13), (m)(2), (m)(11), and (m)(12) of section 401 of such Code, section 410(b) of such Code, and section 416 of such Code. If the employer so excludes such employees with respect to the requirements of any such provision, such employees shall be excluded with respect to the requirements of all such provisions. This subparagraph shall cease to apply to any employee as of the first plan year beginning after the plan year in which the employee completes 1 year of service (without regard to paragraph (1)(B) of this subsection). (B) Time of participation The rules of subsection (a)(4) and section 410(a)(4) of the Internal Revenue Code of 1986 shall apply to such employees. (4) 12-month period For purposes of this subsection, 12-month periods shall be determined in the same manner as under the last sentence of subsection (a)(3)(A), except that 12-month periods beginning before January 1, 2019, shall not be taken into account. . (b) Vesting Section 203(b) of the Employee Retirement Income Security Act of 1974 ( 29 U.S.C. 1053(a) ) is amended by redesignating