Understanding Your Explanation of Benefits
After you receive medical care, your insurance company sends you an Explanation of Benefits — an EOB. It's not a bill. But it's one of the most important documents in your billing journey, and most people throw it away without reading it.
That's a mistake.
Your EOB tells you exactly what was billed, what your insurance paid, what adjustments were made, and what you owe. It's your best tool for catching errors before you pay a single dollar.
What's on an EOB
Every EOB includes:
- Patient name and date of service — who was treated and when
- Provider name — the doctor, hospital, or lab that billed
- Service description and codes — what procedure or visit was billed
- Amount billed — what the provider charged
- Insurance adjustment — the negotiated discount your insurance secured
- Amount paid by insurance — what your plan covered
- Your responsibility — what you owe (copay, coinsurance, deductible)
- Denial reason (if applicable) — why a charge wasn't covered
How to Read It
Start With the Total
Look at "Amount You Owe" or "Patient Responsibility." This is what the provider should be billing you — no more.
Compare Against Your Bill
If the provider's bill is higher than the "Patient Responsibility" on your EOB, something is wrong. Common causes:
- The provider is billing you for the full charge instead of the adjusted amount
- A charge was denied and the provider is balance-billing you (which may be illegal)
- The provider hasn't applied your insurance payment yet
Check for Denied Services
Look for any line items marked "denied" or "not covered." Read the denial reason. Common reasons include:
- Prior authorization not obtained — the provider didn't get pre-approval
- Out-of-network — the provider isn't in your plan's network
- Not medically necessary — the insurer disagrees with the treatment
- Coding error — the wrong code was submitted
Many denials are fixable. A coding error can be corrected by the provider. A medical necessity denial can be appealed with documentation from your doctor.
Verify the Services
Make sure every service listed on the EOB actually happened. If there's a charge for a procedure you never received, that's a billing error — and it may have caused a legitimate claim to be denied due to hitting your deductible prematurely.
What to Do When You Find a Problem
- Contact your insurance company to clarify any confusing entries
- Call the provider's billing department if the bill doesn't match the EOB
- File a formal dispute in writing if the provider won't correct the error
- Appeal any denial you believe is wrong — appeals are overturned far more often than people expect, and most denials are never appealed at all
BillFighter Reads It for You
Upload your EOB or medical bill to BillFighter and our AI cross-references every charge, flags discrepancies, and generates dispute or appeal letters — all in seconds.
Don't throw away your EOB. Use it. Start your analysis free →