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Out-of-Pocket Medical Cost Estimator

What you'd owe under a typical US plan's deductible, coinsurance, and out-of-pocket max.

🔒 Runs entirely in your browser — nothing here is ever uploaded

Last reviewed 2026-08-30

About the Out-of-Pocket Medical Cost Estimator

Models the standard US health-insurance in-network cost-sharing waterfall — deductible, then coinsurance, capped by the out-of-pocket maximum — to estimate what you'd actually owe for a medical bill under your plan.

100% Free Runs in Your Browser No Sign-Up Required
How to use it
  1. Enter the expected total medical bill (the full cost of care before insurance).
  2. Enter your plan's deductible, coinsurance %, and out-of-pocket maximum.
  3. Read what you'd pay, broken into deductible and coinsurance, versus what insurance covers.
Formula
Amount subject to deductible = min(bill, deductible) — you pay 100% of this. Remaining after deductible = bill − that amount. Coinsurance owed = remaining after deductible × coinsurance %. Your total payment = min(deductible amount + coinsurance owed, out-of-pocket max) — capped so you never pay more than the OOP max in a plan year. Insurance pays the rest.
Worked example

A $12,000 medical bill under a plan with a $1,500 deductible, 20% coinsurance, and $5,000 out-of-pocket max: you pay the full $1,500 deductible, then 20% of the remaining $10,500 ($2,100) in coinsurance — a total of $3,600, well under the $5,000 OOP max, with insurance covering the remaining $8,400.

Interpreting your result

Models the standard in-network deductible → coinsurance → out-of-pocket-max waterfall used by most US health plans (verified against HealthCare.gov's own worked example). It doesn't model flat-dollar copays (which typically also count toward the OOP max in real plans), separate out-of-network cost-sharing tiers, family-vs-individual deductible/OOP structures, or $0-cost-sharing preventive care. Premiums are a separate ongoing cost and aren't included here. Check your plan's Summary of Benefits and Coverage for exact numbers — this is an estimate, not a bill.

Recommendations
  • Once you hit your out-of-pocket max, your plan covers 100% of remaining in-network costs for the rest of the plan year — this tool flags when a bill is large enough to reach that point.
  • Copays (flat per-visit fees) aren't modeled here, but they typically also count toward your out-of-pocket max in real plans — factor them in separately if your plan uses copays for some services.
  • Out-of-network care usually has separate (often higher, sometimes unlimited) cost-sharing — this tool assumes in-network care throughout.
Frequently asked questions
The deductible is a fixed dollar amount you pay first, 100% out of pocket, before insurance starts sharing costs. Coinsurance is a percentage of costs you continue to pay after the deductible is met, until you hit your out-of-pocket maximum.
See the full methodology and sources for every finance calculator
Disclaimer

Illustrative estimate only, not financial or tax advice. Verify figures with a licensed adviser or your local tax authority.