Do not pay your medical bill if the amount differs from what your explanation of benefits (EOB) shows you owe. Instead, contact your provider's billing office and your insurance company to identify the source of the difference. About 43% of U.S.
adults report receiving a medical bill or EOB they suspected contained an error, and many differences turn out to be timing mismatches rather than billing mistakes—but some are genuine errors that only show up when you compare them side by side. An EOB is not a bill. It shows what your insurance company decided to pay and what you owe after insurance processing, but the provider's separate bill statement may arrive later or contain charges from a different set of dates or services. Understanding this distinction is your first line of defense: you need both documents to spot real problems.
Table of Contents
- Why Your Bill and EOB Show Different Amounts
- How to Compare Your Bill and EOB
- Recognizing Common Billing Errors
- Calling Your Provider and Insurance Company
- Your Right to Medical Records and Escalation
- Frequently Asked Questions
Why Your Bill and EOB Show Different Amounts
Mismatches between your bill and EOB are common and often have straightforward explanations. Prior balances, insurance payments made after the EOB was issued, or provider billing before insurance finished processing can all create apparent discrepancies.
The bill may combine charges from multiple service dates or visits into one statement while your EOB breaks them into separate line items. Timing is usually the culprit. Your EOB reflects what insurance decided on a specific date, but the provider's bill is sent separately and may reflect later payments or adjustments. The two documents track the same charges from different points in the process. This does not necessarily mean there is an error—it just means you cannot tell yet.
How to Compare Your Bill and EOB
Get an itemized bill from your provider—not a summary, but a detailed account listing every service with its code and date. Compare the procedure codes, service descriptions, dates, and patient name on both documents. Highlight anything that appears on one document but not the other, or that shows a different amount, date, or description.
Look for these specific warning signs: Write down every discrepancy and the line-by-line amounts that do not match. You will need this list when you call.
- A service listed twice with the same date and code
- A charge for a service you did not receive
- A date of service that does not match when you actually went in
- A procedure code or description that does not match what was done (ask your provider to explain any unfamiliar terms)
Recognizing Common Billing Errors
Duplicate charges, upcoding (billing for a more expensive service than provided), unbundling (charging separately for services billed together), and typos in the five-digit CPT code are the most common errors. A single typo in a CPT code can change your charge by hundreds of dollars. If your bill shows a procedure under one code but your EOB shows a different code for the same service, that is a coding mismatch worth clarifying. If you received one injection but the bill shows two, or a consultation rather than a full procedure, those are errors worth disputing.
Calling Your Provider and Insurance Company
Do not pay the bill; instead, call the provider's billing office with your itemized list and EOB in front of you. Ask them to confirm every charge matches a service you actually received. If they cannot explain a charge, ask them to correct or remove it. Document the date, time, and name of the person you spoke with.
Call your insurance company next with the same list. Ask what they processed, what they paid the provider, and what they show as your responsibility. If the bill amount still does not match your EOB, ask your insurer to contact the provider directly. Get a reference number for this inquiry. If your insurance company denied a charge that the bill says you owe, you have the right to appeal that denial—instructions should appear on the EOB itself. You may also request an external independent review if you disagree with the denial.
Your Right to Medical Records and Escalation
You have a federal right under HIPAA to request your own medical records from the provider; they must provide them within 30 calendar days. Use this to verify exactly what was coded and charged. If the provider and your insurer blame each other, or if you cannot get a clear answer after calling both, you can file a complaint with the Consumer Financial Protection Bureau (CFPB) and contact your state Attorney General's office, which investigates deceptive billing practices.
Keep copies of your EOB, itemized bill, medical records, and notes from every call. If the disputed charge reaches a debt collector before the error is resolved, you can file a complaint with the CFPB naming the collector.
Frequently Asked Questions
What if I already paid a bill that turned out to be wrong?
Contact your provider's billing office and request a refund. Once they confirm the charge was incorrect, they should issue one. Keep documentation of your refund request in case you need it later.
How long do I have to dispute a billing error?
There's no federal deadline for disputing a medical bill, but insurance companies have time limits for appealing their decisions—usually 30 to 180 days depending on the appeal type. Don't delay; contact the provider and insurer as soon as you notice the problem.
What if the provider and insurer blame each other for the discrepancy?
This is called "payment dumping." Escalate to your state Attorney General's office and file a complaint with the Consumer Financial Protection Bureau. You should not be stuck in the middle of a dispute between two billing entities.