Methodology & data sources
Transparency is the core of our E-E-A-T: this page documents where every 2026 figure comes from, how often it is refreshed, and the formulas behind each calculator.
Primary data sources
| Source | Covers | Refresh cadence | License |
|---|---|---|---|
| IRS Rev. Proc. 2025-19 | 2026 HSA contribution limits, HDHP minimum deductibles, and HDHP out-of-pocket maximums | annual | Public domain (US Government work) |
| IRS Rev. Proc. 2025-32 | 2026 health flexible spending arrangement (FSA) salary-reduction limit and carryover | annual | Public domain (US Government work) |
| CMS — 2026 Medicare Parts B & D premiums and IRMAA | 2026 Medicare Part B premium and income-related monthly adjustment amounts (IRMAA) | annual | Public domain (US Government work) |
2026 figures we use
- HSA contributions: $4400 self-only, $8750 family, $1000 catch-up at 55+ (IRS Rev. Proc. 2025-19).
- HDHP rules: minimum deductible $1700 / $3400; out-of-pocket maximum $8500 / $17.000 (IRS Rev. Proc. 2025-19).
- Health FSA: $3400 limit, $680 maximum carryover (IRS Rev. Proc. 2025-32).
- Medicare IRMAA: standard 2026 Part B premium $202.90; tiered surcharges based on 2024 MAGI (CMS).
How the calculators work
Calculators run entirely in your browser using standard, published formulas. We do not store or transmit your inputs.
- HSA contribution & growth: remaining room = applicable limit − amounts already contributed; tax saved = contribution × marginal rate; growth compounds a contribution at your chosen annual return.
- FSA planner: tax saved = election × marginal rate; forfeiture risk = election − expenses − any allowed carryover.
- HDHP vs PPO: total annual cost = premiums + expected care up to the deductible, with the HDHP reduced by the HSA tax break and any employer HSA contribution. Coinsurance above the deductible is excluded for simplicity.
- Medicare IRMAA: we match your MAGI to the published CMS bracket for your filing status and report the Part B premium and Part D surcharge.
- HSA-as-retirement: future value of a lump sum plus an annuity of annual contributions at your chosen return.
- Out-of-pocket maximum: you pay 100% to the deductible, then coinsurance, capped at your plan's out-of-pocket maximum (never above the 2026 federal HDHP cap).
Limitations & disclaimer
These tools are simplified models that produce estimates for general information, not medical, tax, insurance, or financial advice, and not official determinations. They may omit factors that matter in your situation (state taxes, coinsurance, plan-specific rules, proration, and eligibility nuances). Always verify against the primary IRS/CMS source and consult a qualified professional. See our disclaimer.
Last updated: 2026-06-14