((a))

((1))

((A)) No pension plan may require, 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 the following dates—

((i)) the date on which the employee attains the age of 21; or

((ii)) the date on which he completes 1 year of service.

((B))

((i)) In the case of any plan which provides that after not more than 2 years of service each participant has a right to 100 percent of his accrued benefit under the plan which is nonforfeitable at the time such benefit accrues, clause (ii) of subparagraph (A) shall be applied by substituting “2 years of service” for “1 year of service”.

((ii)) In the case of any plan maintained exclusively for employees of an educational organization (as defined in ) by an employer which is exempt from tax under , which provides that each participant having at least 1 year of service has a right to 100 percent of his accrued benefit under the plan which is nonforfeitable at the time such benefit accrues, clause (i) of subparagraph (A) shall be applied by substituting “26” for “21”. This clause shall not apply to any plan to which clause (i) applies.

((2)) No pension plan may exclude from participation (on the basis of age) employees who have attained a specified age.

((3))

((A)) For purposes of this section, the term “year of service” means a 12-month period during which the employee has not less than 1,000 hours of service. For purposes of this paragraph, computation of any 12-month period shall be made with reference to the date on which the employee’s employment commenced, except that, in accordance with regulations prescribed by the Secretary, such computation may be made by reference to the first day of a plan year in the case of an employee who does not complete 1,000 hours of service during the 12-month period beginning on the date his employment commenced.

((B)) In the case of any seasonal industry where the customary period of employment is less than 1,000 hours during a calendar year, the term “year of service” shall be such period as may be determined under regulations prescribed by the Secretary.

((C)) For purposes of this section, the term “hour of service” means a time of service determined under regulations prescribed by the Secretary.

((D)) For purposes of this section, in the case of any maritime industry, 125 days of service shall be treated as 1,000 hours of service. The Secretary may prescribe regulations to carry out the purposes of this subparagraph.

((4)) A plan shall be treated as not meeting the requirements of paragraph (1) unless it provides that any employee who has satisfied the minimum age and service requirements specified in such paragraph, and who is otherwise entitled to participate in the plan, commences participation in the plan no later than the earlier of—

((A)) the first day of the first plan year beginning after the date on which such employee satisfied such requirements, or

((B)) the date 6 months after the date on which he satisfied such requirements,

((b))

((1)) Except as otherwise provided in paragraphs (2), (3), and (4), all years of service with the employer or employers maintaining the plan shall be taken into account in computing the period of service for purposes of subsection (a)(1).

((2)) In the case of any employee who has any 1-year break in service (as defined in ) under a plan to which the service requirements of clause (i) of subsection (a)(1)(B) apply, if such employee has not satisfied such requirements, service before such break shall not be required to be taken into account.

((3)) In computing an employee’s period of service for purposes of subsection (a)(1) in the case of any participant who has any 1-year break in service (as defined in ), service before such break shall not be required to be taken into account under the plan until he has completed a year of service (as defined in subsection (a)(3)) after his return.

((4))

((A)) For purposes of paragraph (1), in the case of a nonvested participant, years of service with the employer or employers maintaining the plan before any period of consecutive 1-year breaks in service shall not be required to be taken into account in computing the period of service if the number of consecutive 1-year breaks in service within such period equals or exceeds the greater of—

((i)) 5, or

((ii)) the aggregate number of years of service before such period.

((B)) If any years of service are not required to be taken into account by reason of a period of breaks in service to which subparagraph (A) applies, such years of service shall not be taken into account in applying subparagraph (A) to a subsequent period of breaks in service.

((C)) For purposes of subparagraph (A), the term “nonvested participant” means a participant who does not have any nonforfeitable right under the plan to an accrued benefit derived from employer contributions.

((5))

((A)) In the case of each individual who is absent from work for any period—

((i)) by reason of the pregnancy of the individual,

((ii)) by reason of the birth of a child of the individual,

((iii)) by reason of the placement of a child with the individual in connection with the adoption of such child by such individual, or

((iv)) for purposes of caring for such child for a period beginning immediately following such birth or placement,

((B)) The hours described in this subparagraph are—

((i)) the hours of service which otherwise would normally have been credited to such individual but for such absence, or

((ii)) in any case in which the plan is unable to determine the hours described in clause (i), 8 hours of service per day of such absence,

((C)) The hours described in subparagraph (B) shall be treated as hours of service as provided in this paragraph—

((i)) only in the year in which the absence from work begins, if a participant would be prevented from incurring a 1-year break in service in such year solely because the period of absence is treated as hours of service as provided in subparagraph (A); or

((ii)) in any other case, in the immediately following year.

((D)) For purposes of this paragraph, the term “year” means the period used in computations pursuant to subsection (a)(3)(A).

((E)) A plan may provide that no credit will be given pursuant to this paragraph unless the individual furnishes to the plan administrator such timely information as the plan may reasonably require to establish—

((i)) that the absence from work is for reasons referred to in subparagraph (A), and

((ii)) the number of days for which there was such an absence.

((c))

((1)) ** .—** A pension plan that includes either a qualified cash or deferred arrangement (as defined in ) or a salary reduction agreement (as described in ) shall not require, as a condition of participation in the arrangement or agreement, that an employee complete a period of service with the employer (or employers) maintaining the plan extending beyond the close of the earlier of—

((A)) the period permitted under subsection (a)(1) (determined without regard to subparagraph (B)(i) thereof); or

((B)) the first 24-month period—

((i)) consisting of 2 consecutive 12-month periods during each of which the employee has at least 500 hours of service; and

((ii)) by the close of which the employee has met the requirement of subsection (a)(1)(A)(i).

((2)) ** .—** Paragraph (1)(B) shall not apply to any employee described in .

((3)) ** .—** In the case of employees who are eligible to participate in the arrangement or agreement solely by reason of paragraph (1)(B), or by reason of such paragraph and , the rules of subsection (a)(4) shall apply to such employees.

((4)) ** 12.—** 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 , shall not be taken into account.