(a) Computation period.

1. (1) Under sections 202(b) and 203(b)(3) of the Act and sections 410(a)(5) and 411(a)(6) of the Code, a plan may provide that an employee incurs a one-year break in service for a computation period or periods if the employee fails to complete more than 500 hours of service or, in the case of any maritime industry, 62 days of service in such period or periods.
2. (2) For purposes of section 202(b) of the Act and section 410(a)(5) of the Code, relating to one-year breaks in service for eligibility to participate, in determining whether an employee incurs a one-year break in service, a plan shall use the eligibility computation period designated under § 2530.202-2(b) for measuring years of service after the intital eligibility computation period.
3. (3) For purposes of section 203(b)(3) of the Act and section 411(a)(6) of the Code, relating to breaks in service for purposes of vesting, in determining whether an employee incurs a one-year break in service, a plan shall use the vesting computation period designated under § 2530.203-2(a).
4. (4) For rules regarding service which is not required to be taken into account for purposes of benefit accrual, see § 2530.204-1(b)(1).

(b) Service following a break in service.

1. (1) For purposes of section 202(b)(3) of the Act and section 410(a)(5)(C) of the Code (relating to completion of a year of service for eligibility to participate after a one-year break in service), the following rules shall be applied in measuring completion of a year of service upon an employee's return after a one-year break in service:

   1. (i) In the case of a plan which, after the initial eligibility computation period, measures years of service for purposes of eligibility to participate on the basis of eligibility computation periods beginning on anniversaries of an employee's employment commencement date, as permitted under § 2530.202-2(b)(1), the plan shall use the 12-consecutive-month period beginning on an employee's reemployment commencement date (as defined in paragraphs (b)(1)(iii) and (iv) of this section) and, where necessary, subsequent 12-consecutive-month periods beginning on anniversaries of the reemployment of commencement date.
   2. (ii) In the case of a plan which, after the initial eligibility computation period, measures years of service for eligibility to participate on the basis of plan years beginning with the plan year which includes the first anniversary of the initial eligibility computation period, as permitted under § 2530.202-2(b)(2), the plan shall use the 12-consecutive-month period beginning on an employee's reemployment commencement date (as defined in paragraphs (b)(1)(iii) and (iv) of this section and, where necessary, plan years beginning with the plan year which includes the first anniversary of the employee's reemployment commencement date.
   3. (iii) Except as provided in paragraph (b)(1)(iv) of this section, an employee's reemployment commencement date shall be the first day on which the employee is entitled to be credited with an hour of service described in § 2530.200b-2(a)(1) after the first eligibility computation period in which the employee incurs a one-year break in service following an eligibility computation period in which the employee is credited with more than 500 hours of service.
   4. (iv) In the case of an employee who is credited with no hours of service in an eligibility computation period beginning after the employee's reemployment commencement date established under paragraph (b)(1)(iii) of this section, the employee shall be treated as having a new reemployment commencement date as of the first day on which the employee is entitled to be credited with an hour of service described in § 2530.200b-2(a)(1) after such eligibility computation period.
2. (2) For purposes of section 203(b)(3)(B) of the Act and section 411(a)(6)(B) of the Code (relating to the completion of a year of service for vesting following a one-year break in service), in measuring completion of a year of service upon an employee's return after a one-year break in service, a plan shall use the vesting computation period designated under § 2530.203-2. In the case of a plan which designates a separate vesting computation period for each employee (rather than one vesting computation period for all employees), when an employee who has incurred a one-year break in service later completes an initial hour of service, the plan may change the employee's vesting computation period to a 12-consecutive-month period beginning on the day on which such initial hour of service is completed, provided that the plan follows the rules for changing the vesting computation period set forth in § 2530.203-2(c)(1). Specifically, such a plan must ensure that as a result of the change of the vesting computation period of an employee who has incurred a one-year break in service to the 12-month period beginning on the first day on which the employee later completes an initial hour of service, the employee's vested percentage of the accrued benefit derived from employer contributions will not be less on any date after the change than such nonforfeitable percentage would be in the absence of the change. As under § 2530.203-2(c)(1), the plan will be deemed to satisfy the requirement of that paragraph if, in the case of an employee who has incurred a one-year break in service, the vesting computation period beginning on the day on which the employee completes an hour of service after the one-year break in service begins before the end of the last vesting computation period established before the change of vesting computation periods and, if the employee is credited with 1000 hours of service in both such vesting computation periods, the employee is credited with 2 years of service for purposes of vesting.
3. (3) For purposes of section 203(b)(3)(B) of the Act and section 411(a)(6)(B) of the Code (relating to the completion of a year of service for vesting following a one-year break in service), in measuring completion of a year of service upon an employee's return after a one-year break in service, a plan shall use the vesting computation period designated under § 2530.203-2. In the case of a plan which designates a separate vesting computation period for each employee (rather than one vesting computation period for all employees), when an employee who has incurred a one-year break in service later completes an initial hour of service, the plan may change the employee's vesting computation period to a 12-consecutive-month period beginning on the day on which such initial hour of service is completed, provided that the plan follows the rules for changing the vesting computation period set forth in § 2530.203-2(c)(1).

4. (4) Examples.

   1. (i) Employer X maintains a pension plan. The plan uses a calendar year vesting computation period and plan year. As conditions for participation, the plan requires that an employee of X complete one year of service and attain age 25, and, in accordance with § 2530.202-2(b)(2), provides that after the initial eligibility computation period, plan years will be used as eligibility computation periods, beginning with the plan year which includes the first anniversary of an employee's employment commencement date. Thus, under paragraph (a)(2) of this section, the plan must use plan years in measuring one-year breaks in service for eligibility to participate. The plan provides that an employee acquires a nonforfeitable right to 100 percent of the accrued benefit derived from employer contributions upon completion of 10 years of service. Under the plan, for purposes of vesting, years of service completed before an employee attains age 22 are not taken into account. The plan also provides that if an employee has incurred a one-year break in service, in computing the employee's period of service for eligibility to participate, years of service before such break will not be taken into account until the employee has completed a year of service with X after the employee's return. The plan further provides that in the case of an employee who has no vested right to an accrued benefit derived from employer contributions, years of service for purposes of eligibility to participate or vesting before a one-year break in service for eligibility or vesting (as the case may be) shall not be required to be taken into account if the number of consecutive one-year breaks in service equals or exceeds the aggregate number of such years of service before such consecutive one-year breaks in service.

      1. (A) Employee A commences employment with X on January 1, 1976 at age 30 and completes a year of service for eligibility to participate and vesting in both the 1976 and 1977 computation periods. A becomes a participant in the plan on January 1, 1977. A terminates employment with X on November 3, 1977, after completing 1,000 hours of service; completes no hours of service in 1978, incurring a one-year break in service; and is reemployed by X on June 1, 1979. A completes 800 hours of service during the remainder of 1979 and 600 hours of service from January 1, 1980 through May 31, 1980. Under paragraph (b)(1)(iii) of this section, A's reemployment commencement date is June 1, 1979. By June 1, 1980, A has completed a year of service during the eligibility computation period following his return, and receives credit for his pre-break service to the extent required under section 202 of the Act and section 410 of the Code and the regulations thereunder. The plan is not, however, required to credit A with a year of service for vesting during 1979 because he failed to complete 1,000 hours of service during that vesting computation period. If A completes 400 or more hours of service from June 1, 1980 to December 31, 1980, then A will be credited with one year of service for vesting purposes for the 1980 vesting computation period.
      2. (B) Employee B was born on February 22, 1955 and commenced employment with Employer X on July 1, 1975. B is credited with a year of service for eligibility to participate in the plan for the eligibility computation period beginning on his employment commencement date (July 1, 1975) and a year of service for eligibility and vesting for the 1976 and 1977 plan years. As of the end of the 1977 plan year, B is credited with 3 years of service for purposes of eligibility to participate, but only one year of service for purposes of vesting. Not having attained age 25, however, B is not admitted to participation in the plan upon completion of his first year of service with X. In the 1978 plan year, B fails to be credited with 500 hours of service, thereby incurring a one-year break in service. As a result of B's one-year break in service in the 1978 plan year, the year of service for vesting which was earlier credited to B for the 1977 plan year is disregarded because the one-year break in service equals the one year of service credited to B before the one-year break in service. After the end of the 1978 plan year, B does not perform an hour of service with X until February 3, 1979. February 3, 1979, therefore, is B's reemployment commencement date under paragraph (b)(1)(i) of this section. B fails to be credited with 1,000 hours of service in the first eligibility computation period beginning on February 3, 1979, and also for the vesting computation period beginning January 1, 1979. Because, in accordance with § 2530.202-2(b)(2), the plan provides that after the initial eligibility computation period, plan years will be used as eligibility computation periods, under paragraph (b)(1)(ii) of this section the plan must provide that, in measuring completion of a year of service for eligibility to participate after a one-year break in service, plan years beginning with the plan year which includes an employee's reemployment commencement date will be used. B is credited with 1,000 hours of service for the plan year beginning on January 1, 1980 and is therefore credited with a year of service for the 1980 plan year. Under section 202(b)(3) of the Act and section 410(a)(5)(C) of the Code, as a consequence of B's completion of a year of service in the 1980 plan year, B's service before his one-year break in service in the 1978 plan year must be taken into account for eligibility purposes. As conditions of participation, the plan requires that an employee attain age 25 and complete one year of service. Upon his completion of a year of service for the 1980 plan year, B is deemed to have met the plan's participation requirements as of February 22, 1980, his twenty-fifth birthday, because the year of service completed by B in B's eligibility computation period beginning on January 1, 1976 is taken into account for eligibility purposes.
   2. (ii) Employer Y maintains a defined benefit pension plan. The plan provides that an employee acquires a nonforfeitable right to 100 percent of the employee's accrued benefit derived from employer contributions upon completion of 10 years of service. As conditions for participation, the plan requires that an employee of Y complete one year of service and provides that if an employee has incurred a one-year break in service, in computing the employee's period of service for eligibility to participate, years of service before such break will not be taken into account until the employee has completed a year of service with Y after the employee's return. In accordance with § 2530.202-2(b)(1), the plan provides that after the initial eligibility computation period, eligibility computation periods beginning on anniversaries of an employee's employment commencement date will be used. Thus, under paragraph (a)(1) of this section, the plan must use computation periods beginning on anniversaries of the employee's employment commencement date in measuring one-year breaks in service. Employee C's employment commencement date with Y is February 1, 1975, C is credited with a year of service for eligibility to participate in the eligibility computation period beginning on C's employment commencement date and meets the plan's eligibility requirements as of February 1, 1976. In accordance with the provisions of the plan, C commences participation in the plan as of July 1, 1976. C is thereafter credited with a year of service for eligibility to participate in each of the eligibility computation periods beginning on anniversaries of C's employment commencement date (February 1) in 1976, 1977, 1978 and 1979. Thus, as of February 1, 1980, C is credited with 5 years of service for eligibility to participate. In the eligibility computation period beginning on February 1, 1980, C fails to be credited with more than 500 hours of service and therefore incurs a one-year break in service. In the eligibility computation period beginning on February 1, 1981, C is not credited with an hour of service for the performance of duties until March 1, 1981. Under paragraph (b)(1)(iii) of this section, March 1, 1981 is C's reemployment commencement date. C terminates employment with Y on May 1, 1981 and fails to be credited with 1000 hours of service in the 12-consecutive-month period beginning on March 1, 1981, or with more than 500 hours of service in the eligibility computation period beginning on February 1, 1981, thereby incurring a second one-year break in service for eligibility to participate. C is credited with no hours of service in the eligibility computation period beginning on February 1, 1982, thereby incurring a third one-year break in service for eligibility to participate, and is likewise credited with no hours of service in the 12-consecutive-month period beginning on March 1, 1982, the anniversary of B's reemployment commencement date. Under paragraph (b)(1)(iv) of this section, C must therefore be treated as having a new reemployment commencement date as of the first day following the close of the eligibility computation period beginning on February 1, 1982. On January 1, 1984 (before the end of the eligibility computation period beginning February 1, 1983) C is rehired by Y and is credited with an hour of service for the performance of duties. C is therefore treated as having a new reemployment commencement date January 1, 1984. C fails to be credited with more than 500 hours of service in the eligibility computation period beginning on February 1, 1983, thereby incurring a fourth one-year break in service, and fails to be credited with 1000 hours of service in the 12-consecutive-month period beginning on March 1, 1983, the anniversary of C's original reemployment commencement date. However, in the 12-consecutive-month period beginning on January 1, 1984, C is credited with 1000 hours of service, thus meeting the plan's requirement that an employee who has incurred a one-year break in service for eligibility to participate must complete a year of service upon the employee's return in order for years of service before the one-year break in service to be taken into account for purposes of eligibility. Because C's years of service completed before C's first one-year break in service must be taken into account under section 202(b) of the Act and section 410(b)(5) of the Code for purposes of eligibility to participate, under § 2530.204-2(a)(2) the period beginning on July 1, 1976 (the earliest date on which C was a participant) and extending until January 31, 1980 (the last day before C's first one-year break in service) must be taken into account for purposes of benefit accrual.