((a)) ** One-out-of-two requirement** A participant must complete, within the last two years before any separation from service (except a separation because of death or disability) at least one year of creditable civilian service during which the participant is subject to this subchapter and in a pay status before the participant or the participant’s survivors are eligible for an annuity under this subchapter based on that separation.

((b)) ** Refund of contributions for time not allowed for credit** If a participant (other than a participant separated from the service because of death or disability) fails to meet the service and pay status requirement of subsection (a), any amounts deducted from the participant’s pay during the period for which no eligibility is established based on the separation shall be returned to the participant on the separation.

((c)) ** Exception** Failure to meet the service and pay status requirement of subsection (a) shall not deprive the participant or the participant’s survivors of any annuity to which they may be entitled under this subchapter based on a previous separation.