Every formula. Every assumption. Every source.

• The 1.1% boost only applies when BOTH conditions are met — age 62+ AND 20+ years. Age 62 with 19 years gets 1.0%.
• There is no maximum annuity under FERS (OPM Handbook Ch. 50) — the 80%-of-High-3 ceiling you may have heard of applies only to CSRS.
• High-3 is the average of your 3 highest consecutive years of base pay — not your final salary.
• Part-time service is counted at full calendar time for eligibility, and the whole pension is then reduced by the ratio of hours actually worked to full-time hours, using High-3 at full-time pay rates (OPM Handbook Ch. 55; 5 U.S.C. 8415(g)). FedHorizon's report does not model part-time history — see Known limitations.

OPM FERS Handbook, Chapter 50 (Sections 50A–50B). Appendix A for MRA table.

• Mandatory retirement: LEO/FF must retire by 57; ATC by 56. Waivers are rare and must be requested annually.
• Immediate retirement: special-category employees can retire at age 50 with 20 covered years, or at any age with 25 (5 U.S.C. 8412(d)/(e)). This is their regular retirement — not VERA.
• The 1.7% rate applies only to covered service — years in a non-special position don't qualify for the higher rate.
• The enhanced rate itself requires meeting 25 covered years at any age, or 20 covered years at age 50+ (5 U.S.C. 8412(d)/(e)). Fall short of both and the standard 1.0%/1.1% formula applies to all your service instead — not a partial 1.7% credit for whatever covered years you do have.

OPM FERS Handbook, Chapter 50, Section 50C. 5 U.S.C. 8412(d)/(e), 8415(e).

• Not available under MRA+10 early retirement — only full-eligibility retirements qualify.
• Disability retirees and special category retirees have different rules.
• Investment income, rental income, and Social Security itself do NOT count toward the earnings limit.
• The supplement is fully taxable as ordinary income.

OPM FERS Handbook, Chapter 51 (FERS Annuity Supplement). 5 U.S.C. 8421.

• If you elect no survivor benefit, your spouse must consent in writing — OPM requires notarized spousal waiver.
• Former spouse court orders (QDRO equivalents) can override your election.
• The survivor benefit is not just for death — it also continues through divorce if a court orders it.
• FEHB coverage for a surviving spouse requires either the full or partial survivor election.

OPM FERS Handbook, Chapter 70 (Survivor Benefits). 5 U.S.C. 8442.

• Standard catch-up ($8,000 extra in 2026) available at age 50+ — the engine includes these.
• Super catch-up ($11,250 extra in 2026) available for ages 60–63 under SECURE Act 2.0.
• Agency match is always Traditional, even if your own contributions are Roth.
• The engine uses nominal returns — inflation-adjusted comparisons are shown separately in the report.
• TSP contribution limits: $24,500 employee + $8,000 catch-up (2026 limits, updated annually).

TSP.gov Bulletin 25-3 (2026 limits). IRS Notice 2025-67. SECURE Act 2.0 109 (super catch-up).

• Crediting military service toward a FERS annuity may require waiving military retired pay. Important exceptions apply, including certain reserve-component and disability-related retired pay — confirm your situation with your agency benefits office.
• Reserve/National Guard retirement (20+ qualifying years) is treated differently than active duty.
• Interest generally begins two years after you start FERS-covered civilian service and varies by year — your agency payroll office provides the official deposit amount, including interest.
• Deposited military service counts toward retirement eligibility (e.g. MRA+30 or 60+20), and those immediate retirements carry the FERS Supplement. But the Supplement amount itself is computed from civilian FERS service only — military time is excluded (OPM Handbook Ch. 51). For special-category retirement, military time does not count toward the 20 covered years.

OPM FERS Handbook, Chapter 23 (Military Service). 5 U.S.C. 8332.