IRS Regulation 1.411(a)-5 (shown below) says that for a plan that uses computation periods, service within a computation period during which an employee attains age 22 must be taken into account for vesting. Should this regulation be used for guidance as if it had been updated to replace "age 22" with "age 18"? Or should the regulation be ignored since it has not been updated?
1.411(a)-5 Service included in determination of nonforfeitable percentage.
(a) In general.
Under section 411(a)(4), for purposes of determining the nonforfeitable percentage of an employee's right to his employer-derived accrued benefit under section 411(a)(2) and § 1.411(a)-3, all of an employee's years of service with an employer or employers maintaining the plan shall be taken into account except that years of service described in paragraph (B) of this section may be disregarded.
(B) Certain service.
For purposes of paragraph (a) of this section, the following years of service may be disregarded:
(1) Service before age 22.
(i) In the case of a plan which satisfies the requirements of section 411(a)(2) (A) or (B) (relating to 10-year vesting and 5-15-year vesting, respectively), a year of service completed by an employee before he attains age 22.
(ii) In the case of a plan which does not satisfy the requirements of section 411(a)(2) (A) or (B), a year of service completed by an employee before he attains age 22 if the employee is not a participant (for purposes of section 410) in the plan at any time during such year.
(iii) For purposes of this subparagraph in the case of a plan utilizing computation periods, service during a computation period described in section 411(a)(5)(A) within which the employee attains age 22 may not be disregarded. In the case of a plan utilizing the elapsed time method described in § 1.410(a)-7, service on or after the date on which the employee attains age 22 may not be disregarded.