What is the allowed amount?

The allowed amount (also called the "negotiated rate" or "approved amount") is the maximum your insurer will pay for a covered service. If you use an in-network provider, the provider must accept this amount and cannot bill you more than your share of it.

Coinsurance is the percentage of covered costs you pay after meeting your deductible. With 20% coinsurance, you pay 20% of the allowed amount for each service and your insurer pays the remaining 80%, until you reach your out-of-pocket maximum.

How does the deductible affect coinsurance?

You must first pay your full deductible before coinsurance applies. If your remaining deductible is $500 and the bill is $800, you pay $500 toward the deductible and then your coinsurance percentage applies to the remaining $300.

What is the out-of-pocket maximum?

The out-of-pocket maximum (OOP max) is the most you will pay in a plan year. Once reached, your insurer pays 100% of covered costs. Deductible payments and coinsurance all count toward this cap.

Does this calculator include copays?

No. Copays are a flat fee charged at the time of service and are separate from coinsurance. Some plans charge a copay instead of coinsurance for certain services (e.g. $30 for a primary care visit). Enter only the coinsurance rate that applies to this service.

What if the allowed amount is less than the billed amount?

Always enter the allowed (negotiated) amount, not the provider's original billed amount. In-network providers write off the difference between the billed and allowed amounts; you are not responsible for that portion.

Does this calculate property insurance coinsurance penalties?

No. This calculator is for health insurance and patient medical bills (deductible, coinsurance %, and out-of-pocket maximums). Property insurance coinsurance uses a separate replacement cost formula to determine underinsurance penalties.

Coinsurance Calculator

Enter your allowed amount, deductible status, coinsurance rate, and OOP max to see exactly what you owe.

Health insurance cost estimator: This tool calculates patient out-of-pocket shares for medical services (deductibles, coinsurance %, and OOP maximums). It does not calculate property or commercial insurance coinsurance penalty clauses.

Bill Details

Allowed Amount ($)

The negotiated rate your insurer accepts for this service.

Your Coinsurance Rate (%)

Your share after the deductible is met (typically 10–30%).

Plan Year Status

Annual Deductible ($)

Deductible Already Met ($)

Out-of-Pocket Maximum ($)

OOP Max Already Met ($)

Summary

Coinsurance is the percentage of covered medical costs you pay after meeting your deductible. For example, with a 20% coinsurance rate on a $1,000 allowed bill you owe $200 — until your out-of-pocket maximum is reached, after which the insurer covers 100%. This calculator breaks down a single medical bill into exactly what you pay and what insurance pays, accounting for your remaining deductible and OOP max.

How it works

Enter the allowed amount — the negotiated rate your insurer accepts for the service.
Enter your coinsurance percentage (typically 10%, 20%, or 30%).
Enter your annual deductible and how much of it you have already met.
Enter your out-of-pocket maximum and how much you have already paid toward it.
Click Calculate to see: amount applied to deductible, coinsurance owed, insurer share, and your total cost.

Use cases

Estimating your share before a scheduled procedure or specialist visit.
Understanding an Explanation of Benefits (EOB) statement from your insurer.
Comparing cost scenarios for elective vs. urgent care at different points in the plan year.
Checking whether a large bill will push you past your out-of-pocket maximum.
Verifying that a hospital bill matches what your plan should require you to pay.
Teaching family members how coinsurance works with a concrete example.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu