Patient guide Ā· 7-min read
How to Read an Explanation of Benefits (EOB)
Your insurer's EOB is the single most useful document for disputing a hospital bill. Here is how to read every field on it ā and what to compare it to.
What an EOB is ā and is not
An Explanation of Benefits is not a bill. It is the insurer's record of how a claim was processed: what the provider billed, what the insurer accepted as the negotiated rate (the "allowed amount"), what the insurer paid, and what is left for you. The hospital sends a separate bill. Disputes happen at the intersection: the bill should not exceed the EOB's patient-responsibility amount.
The five columns that matter
Every EOB shows roughly these fields per claim line:
ā¢ Provider charge ā what the hospital submitted. ā¢ Allowed amount ā the contractually negotiated rate the in-network provider agreed to accept. The hospital cannot bill you more than this. ā¢ Plan payment ā what the insurer paid. ā¢ Patient responsibility ā your deductible + co-insurance + co-pay, all summed. ā¢ Remark codes ā short explanations of any adjustments.
The key check: hospital bill ā¤ EOB patient responsibility, per line.
Common EOB remark codes
PR-1 = patient responsibility / deductible. PR-2 = co-insurance. PR-3 = co-pay. CO-45 = contractual write-off (the difference between provider charge and allowed amount; the patient cannot be billed for this). CO-96 = non-covered service. OA = other adjustment. If you see CO-45 with a large amount and the hospital is still trying to bill you that amount, that is a balance-billing violation.
When the EOB is your most powerful document
If your hospital bill has line items above the EOB patient responsibility, you have a documented contract violation. The dispute letter the rule engine generates encloses the EOB, identifies the mismatched lines, and asks for a corrected statement.
Frequently asked
How long do I have to wait for an EOB?
Most claims appear in the insurer's member portal within 2-4 weeks. The hospital should not send the patient bill until after the EOB is final.
My EOB shows the claim as "pending" ā should I pay the hospital bill?
No. Until the claim is finalized, the patient-responsibility amount is not determined. Paying early can complicate disputes.
Related billing-error explainers
Bill Exceeds Your EOB
The hospital is billing you more than your insurer's Explanation of Benefits assigned as your responsibility.
No Surprises Act Violations
Out-of-network provider billing more than in-network cost-share at an in-network facility.
Duplicate Charges on a Hospital Bill
Same service billed more than once on a single visit.
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