Federal Retirement Library

OPM's own overview of how FERS retirement works: eligibility, the pension formula, and what happens at each stage of applying.

Use this when: you want the government's own starting-point explanation of FERS, not a third party's summary of it.

The detailed rulebook OPM's own payroll and personnel offices use — service credit, eligibility, annuity computation, disability, and survivor benefits, chapter by chapter.

Use this when: you want to verify the exact rule behind a FedHorizon calculation, not just a summary of it.

What counts toward your years of service for pension purposes — civilian time, unused sick leave, and military deposits.

Use this when: you're not sure whether a specific period of your career (part-time work, a break in service, military time) counts toward your pension.

The different paths into retirement — immediate, early, deferred, and disability — and what qualifies you for each.

Use this when: your situation doesn't look like a standard immediate retirement (you're leaving before your MRA, or before you're fully vested).

The official age-and-service tables for when you can retire, including your Minimum Retirement Age (MRA).

Use this when: you want to confirm your MRA directly from OPM rather than a calculator's projection of it.

OPM's central hub for the Federal Employees Health Benefits program — plan types, enrollment, and premiums.

Use this when: you want the authoritative description of how FEHB works, before layering retirement rules on top of it.

OPM's own tool for comparing FEHB plan premiums and coverage side by side.

Use this when: you're deciding which FEHB plan to carry into retirement, not just whether you're eligible to keep FEHB at all.

OPM's guidance on the five-year continuous coverage rule and what happens to your FEHB enrollment at retirement.

Use this when: you want to confirm the five-year rule directly, especially if your coverage history has any gaps.

Medicare's own explanation of who's eligible, when to enroll, and how Medicare coordinates with other coverage like FEHB.

Use this when: you're within a few years of 65 and need to understand how Medicare enrollment interacts with your FEHB plan.

The Thrift Savings Board's own introduction to how the TSP works — contributions, agency matching, and fund options.

Use this when: you want the plan administrator's own explanation, not a third-party summary of TSP rules.

The current-year elective deferral and catch-up contribution limits, published directly by TSP.gov.

Use this when: you want this year's exact contribution ceiling rather than a cached figure from a calculator.

The official description of the G, F, C, S, I, and Lifecycle funds — what each one actually invests in.

Use this when: you're deciding how to allocate your TSP and want the fund descriptions straight from TSP.gov.

The IRS rule (IRC §402(g)) that sets the elective deferral limit TSP.gov's own contribution page is built on.

Use this when: you want the underlying tax-code authority behind the TSP contribution limit, not just the published number.

Your actual Social Security Statement — earnings record and personalized benefit estimates at different claiming ages.

Use this when: you're entering a Social Security estimate into a FedHorizon calculator and want your real number instead of a modeled one.

SSA's own explanation of how much your benefit grows for every year you delay claiming past your full retirement age, up to 70.

Use this when: you're deciding whether to claim Social Security early, at full retirement age, or delay it to 70.

SSA's table showing exactly how much your benefit is reduced for claiming before your full retirement age.

Use this when: you're modeling claiming at 62 and want the exact reduction percentage rather than a rule of thumb.

OPM's guidance on the FERS survivor annuity election — the 25% and 50% options, and how each affects your own pension.

Use this when: you want to verify the survivor election rules directly before making what is generally an irrevocable choice.

OPM's rules on buying back prior active-duty military service so it counts toward your FERS pension.

Use this when: you served on active duty before your federal civilian career and want to confirm the deposit rules directly.