employer contributions, and (ii) satisfies sections 401(k)(3)(A)(ii), 401(m)(2), and 416 taking into account all applicable rules, including— (I) paragraphs (11), (12), and (13) of section 401(k), (II) paragraphs (10), (11), and (12) of section 401(m), and (III) section 416(g)(4)(H). (D) Grandfathered automatic contribution plan A plan described in clause (i), (ii), (iv), (v), or (vi) of section 219(g)(5)(A) that— (i) is maintained by an employer as of the date of enactment of the Automatic Retirement Plan Act of 2017 , (ii) has been maintained by such employer (or a predecessor employer) for at least 1 year before such date of enactment, and (iii) except as provided by the Secretary, has not had its coverage or benefits substantially decreased for any plan year beginning after such date of enactment. (3) Eligibility requirements (A) In general Subject to subparagraph (B), the eligibility requirements described in this paragraph are that all employees of the employer are eligible to participate in an automatic contribution plan maintained by the employer. (B) Certain exclusions Subparagraph (A) shall not apply to the following: (i) Individuals less than 21 years old The employer may, but need not, include an employee who has not attained age 21 in an automatic contribution plan maintained by the employer. (ii) Certain other employees The employer may, but need not, include an employee described in section 410(b)(3) in an automatic contribution plan maintained by the employer. (iii) Part time employees, etc No employee may be treated as ineligible in an automatic contribution plan maintained by the employer solely by reason of working on a part-time, temporary, or seasonal basis, except as otherwise provided in this subparagraph. (iv) New employee The employer may, but need not, exclude an employee from an automatic contribution plan maintained by the employer until the first day of the second calendar month beginning on or after the day the individual begins work for the employer. (v) Seasonal or temporary