How do I calculate what I owe from my EOB?

Add the amounts applied to your deductible, copay and coinsurance, plus anything marked not covered. That total is your patient responsibility, and it should match the provider’s bill. Plan paid plus your deductible, copay and coinsurance should equal the allowed amount.

Why is my medical bill higher than my EOB?

The bill may have been sent before the claim finished processing, the provider may be billing you for the difference between its charge and the allowed amount (balance billing), or there may be a coding or billing error. Ask for an itemized bill and ask your insurer whether the claim is final.

Can an in-network provider bill me more than my EOB says?

HealthCare.gov says a preferred (in-network) provider may not balance bill you for covered services. If the claim is final and the bill is still higher, ask the provider why and tell your insurer.

When does the No Surprises Act protect me?

CMS says it protects most people with private insurance from unexpected out-of-network bills for emergency room visits, non-emergency care linked to a visit to an in-network hospital, hospital outpatient department or ambulatory surgical center, and air ambulance services. The help desk is 1-800-985-3059.

Does this EOB decoder send my figures anywhere?

No. The arithmetic and the paste box both run in your browser, nothing is stored, and no AI reads your text. Close the page and the figures are gone.

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EOB decoder: what do you owe, and does the bill match?

Type in the figures from one line of your explanation of benefits (EOB). The decoder explains each number, adds up what you may owe — deductible + copay + coinsurance + anything not covered — checks the figures agree, and tells you whether the provider’s bill matches. It runs on your device; nothing is sent or saved.

Paste text from your EOB instead

Copy the text of one claim line from your insurer’s portal or a PDF. It is read on this device, never sent anywhere.

From the EOB line

Amount billed

Also “provider charges” or “total charges”.

Allowed amount

Also “plan allowance”, “eligible amount” or “negotiated rate”.

Plan paid

Also “paid by plan” or “insurance paid”.

Your share, as the EOB splits it

Applied to deductible

The part “applied to deductible”.

Copay

A flat amount, such as $30.

Coinsurance

Your percentage share, shown in dollars.

Not covered

Only if the EOB shows one.

Patient responsibility on the EOB

Also “you may owe” or “your share”. Optional: used to check the parts.

From the provider’s bill

Amount due on the provider’s bill

From the provider’s bill for the same date and service. Optional.

About the provider

Was the provider in your plan’s network?In-networkOut-of-networkNot sure

Was this care one of these?Used only to say whether the No Surprises Act may apply.

How to use it

Find one claim line on your EOB — one date of service and one provider. An EOB can list several lines; decode them one at a time.
Copy the amounts into the boxes: amount billed, allowed amount, plan paid, and the parts of your share. Leave a box empty if the EOB doesn’t show it. Or open “Paste text from your EOB”, paste the text from your insurer’s portal, and check every figure it fills.
If you have the provider’s bill, enter its amount due, and say whether the provider was in-network and where the care happened.
Press Decode. Anything that doesn’t add up, or a bill that asks for more, is flagged with what to ask.

How the numbers are worked out

Your share starts from the allowed amount, not the billed amount. HealthCare.gov defines the allowed amount as the maximum a plan will pay for a covered service, also called the negotiated rate. For an in-network provider, the gap between the billed amount and the allowed amount is usually a discount you don’t pay.

Within the allowed amount, the EOB splits the cost between the plan and you. Your part is made of the deductible (what you pay before the plan starts to pay), a copay (a fixed amount, such as $30) and coinsurance (a percentage, such as 20%). The decoder checks that plan paid + deductible + copay + coinsurance = allowed amount, allowing a cent for rounding. Some EOBs count a not-covered amount inside the allowed amount and some show it separately, so both layouts are accepted.

Then it adds deductible + copay + coinsurance + not covered to get your patient responsibility, and compares that with the total printed on the EOB if you entered it. The figure the bill is compared with is the EOB’s printed total when you give one, otherwise the sum of the parts.

When the bill asks for more than the EOB

A bill higher than the EOB’s patient responsibility usually means one of three things:

The claim was still being processed. Providers sometimes bill before the insurer’s payment and discount are applied — a bill for the full charge is the giveaway. Ask the billing office to check your account against the EOB.
Balance billing. HealthCare.gov describes this as a provider billing you for the difference between its charge and the allowed amount. It says a preferred (in-network) provider may not balance bill you for covered services.
A coding or billing error. A wrong code, date or a duplicate line can push the bill up. Ask for an itemized bill and compare it line by line with the EOB.

For out-of-network care, the federal No Surprises Act may apply. CMS says it protects most people with private insurance from unexpected out-of-network bills for emergency room visits, for non-emergency care related to a visit to an in-network hospital, hospital outpatient department or ambulatory surgical center, and for air ambulance services. In most of those cases you can’t be charged more than your in-network cost-sharing. CMS lists exceptions — ground ambulances, and protections given up by signing a notice and consent form among them — and runs a help desk on 1-800-985-3059.

What this tool doesn’t do

It doesn’t know your plan, so it can’t tell whether a service should have been covered, whether a deductible was applied correctly, or what your plan’s coinsurance rate is. It reads only the figures you give it, and the paste box only finds amounts written next to a label on the same line. It can’t decide whether a law applies to your bill; your insurer and CMS can.

Common questions

How do I calculate what I owe from my EOB?: Add the amounts applied to your deductible, copay and coinsurance, plus anything marked not covered. That total is your patient responsibility, and it should match the provider’s bill. Plan paid plus your deductible, copay and coinsurance should equal the allowed amount.
Why is my medical bill higher than my EOB?: The bill may have been sent before the claim finished processing, the provider may be billing you for the difference between its charge and the allowed amount (balance billing), or there may be a coding or billing error. Ask for an itemized bill and ask your insurer whether the claim is final.
Can an in-network provider bill me more than my EOB says?: HealthCare.gov says a preferred (in-network) provider may not balance bill you for covered services. If the claim is final and the bill is still higher, ask the provider why and tell your insurer.
When does the No Surprises Act protect me?: CMS says it protects most people with private insurance from unexpected out-of-network bills for emergency room visits, non-emergency care linked to a visit to an in-network hospital, hospital outpatient department or ambulatory surgical center, and air ambulance services. The help desk is 1-800-985-3059.
Does this EOB decoder send my figures anywhere?: No. The arithmetic and the paste box both run in your browser, nothing is stored, and no AI reads your text. Close the page and the figures are gone.

Sources

Definitions and rules on this page come from these official pages, checked 27 Oct 2026.