How to read an Explanation of Benefits (EOB) — and catch billing errors

An Explanation of Benefits (EOB) is not a bill. But it's one of the most important documents you receive after using your health insurance — and most people throw it away without reading it.

Understanding your EOB is one of the most practical ways to catch billing errors, ensure your insurance applied correctly, and avoid paying more than you owe.

What an EOB is

After you receive a covered medical service, your insurance company processes the claim and sends you an EOB. It summarizes:

• What service was provided
• What was billed (the provider's charge)
• What your insurer allowed (the negotiated rate)
• What your insurer paid
• What you owe (your share: deductible, copay, coinsurance)

You'll typically receive an EOB before the provider sends you an actual bill. Your out-of-pocket responsibility should match on both documents.

The key sections of an EOB

What was billed: The provider's full charge. This is often much higher than the negotiated rate and not what you'll actually pay.

Negotiated discount: The discount your insurer has with in-network providers. This is the benefit of using in-network care — the "allowed amount" is significantly lower than the billed amount.

What the plan paid: The amount your insurer paid after applying the negotiated rate, your deductible, and any applicable copays or coinsurance.

Your responsibility: What you owe the provider. This should be the total you pay — the combination of whatever deductible amount remained plus your coinsurance or copay.

Your deductible status: Most EOBs show how much of your deductible you've met and how much remains. This is useful for planning purposes.

Your out-of-pocket status: Many EOBs also show your progress toward your out-of-pocket maximum.

Common billing errors to look for

Medical billing errors are remarkably common — estimates suggest errors appear in 30–80% of medical bills. The most common issues:

Wrong person billed. Verify your name and insurance information match what's on file.

Duplicate billing. A service appears on the EOB twice — a common coding error.

Upcoding. The provider billed for a more expensive service than was actually provided (e.g., a complex office visit when a basic visit occurred).

Services marked as not covered. Sometimes a covered service is coded incorrectly and processed as non-covered. This is worth appealing.

Out-of-network provider surprise. If a provider you thought was in-network is processed as out-of-network, verify the claim was coded correctly and check whether surprise billing protections apply.

Pre-authorization issues. Some services require prior authorization. If this wasn't obtained and the claim is denied, the provider's office may be responsible — not you.

What to do when something looks wrong

• Compare the EOB to the bill you receive from the provider. They should match. If they don't, call the provider's billing department.
• If the EOB shows a service was processed incorrectly (wrong coverage tier, out-of-network when in-network), call your insurer and ask them to reprocess the claim.
• If your insurer denies a claim, you have the right to appeal. Your EOB should include information about the appeals process.
• Keep your EOBs until you've verified the corresponding bill and confirmed the amount was correct. For major procedures, keep them longer — they're important records.

LifQ organizes your healthcare documents and helps you track when bills and EOBs don't match — so you can catch errors before paying.