5 U.S.C. § 8333 — Eligibility for annuity

(a) To ever qualify for an annuity under this subchapter, an employee must first complete at least 5 years of civilian service. (b) There's also a recent-service requirement. Except when someone leaves because of death or disability, the employee or Member must have worked at least 1 year of creditable civilian service, while covered by this subchapter, sometime in the last 2 years before they separate. That 1 year must fall within that final 2-year window for the person (or their survivors) to be eligible for an annuity based on that separation. If someone fails to meet this requirement, and didn't leave because of death or disability, they get back the retirement deductions taken from their pay during the service that couldn't earn annuity eligibility because of the separation. Missing this requirement on one separation doesn't cancel annuity rights that already vested from an earlier separation. (c) A Member, or the Member's survivor, is eligible for an annuity under this subchapter only if the required deductions or deposits under section 8334 have actually been made. Normally that means deductions or deposits covering the Member's last 5 years of civilian service. But for a survivor annuity payable under section 8341(d) or (e)(1), the deductions or deposits must instead cover the Member's total service.