(a) General rule. Except as provided by paragraph (b) or (c) of this section, a plan is not a qualified plan (and a trust forming a part of such plan is not a qualified trust) if the plan requires, as a condition of participation in the plan, that an employee complete a period of service with the employer or employers maintaining the plan extending beyond the later of—
(1) Age 25. The date on which the employee attains the age of 25; or
(2) One year of service. The date on which the employee completes 1 year of service.
(b) Special rule for plan with 3-year 100 percent vesting. A plan which provides that after not more than 3 years of service each participant's right to his accrued benefit under the plan is completely nonforfeitable (within the meaning of section 411 and the regulations thereunder) at the time such benefit accrues satisfies the requirements of paragraph (a) of this section if the period of service required by the plan as a condition of participation does not extend beyond the later of—
(1) Age 25. The date on which the employee attains the age of 25; or
(2) Three years of service. The date on which the employee completes 3 years of service.
(c) Special rule for employees of certain educational institutions. A plan maintained exclusively for employees of an educational institution (as defined in section 170(b)(1)(A)(ii)) by an employer exempt from tax under section 501(a) which provides that after 1 year of service each participant's right to his accrued benefit under the plan is completely nonforfeitable (within the meaning of section 411 and the regulations thereunder) at the time such benefit accrues satisfies the requirements of paragraph (a) of this section if the period of service required by the plan as a condition of participation does not extend beyond the later of—
(1) Age 30. The date on which the employee attains the age of 30; or
(2) One year of service. The date on which the employee completes 1 year of service.
(d) Other conditions. Section 410(a), §1.410(a)-4, and this section relate solely to age and service conditions and do not preclude a plan from establishing conditions, other than conditions relating to age or service, which must be satisfied by plan participants. For example, such provisions would not preclude a qualified plan from requiring, as a condition of participation, that an employee be employed within a specified job classification. See section 410(b) and the regulations thereunder for rules with respect to coverage of employees under qualified plans.
(e) Age and service requirements—(1) General rule. For purposes of applying the rules of this section, plan provisons may be treated as imposing age or service requirements even though the provisions do not specifically refer to age or service. Plan provisions which have the effect of requiring an age or service requirement with the employer or employers maintaing the plan will be treated as if they imposed an age or service requirement. In general, a plan under which an employee cannot participate unless he retires will impose an age and service requirement. However, a plan may provide benefits which supplement benefits provided for employees covered under a pension plan, as defined in section 3(2) of the Employee Retirement Income Security Act of 1974, satisfying the requirements of section 410(a)(1) without violating the age and service rules.
(2) Examples. The rules of this paragraph are illustrated by the following examples:
(Sec. 410 (88 Stat. 898; 26 U.S.C. 410))
[T.D. 7508, 42 FR 47194, Sept. 20, 1977]