Is the EOB the same as a bill?

No. The EOB is from your insurer and summarizes the claim. The bill is from your provider. Always wait for the bill and compare it to the EOB before paying.

What does 'patient responsibility' mean?

It's the portion of the allowed amount your plan didn't cover - usually your deductible, copay, coinsurance, or non-covered charges. It's the most the provider can bill you for an in-network covered service.

Yes. If a claim was denied or paid less than expected, you can request an internal appeal. The appeal deadline typically runs from the EOB date.

Guide

How to read your EOB

Your Explanation of Benefits is your insurer's version of the story. Read it carefully - denials and overbilling hide here.

What an EOB is - and isn't

An Explanation of Benefits is NOT a bill. It is your insurer's summary of a claim: what the provider billed, what the plan allowed, what the plan paid, and what you might owe. The actual bill comes from the provider - and it should match the 'patient responsibility' column.

The columns that matter

Look for: Amount billed (what the provider charged), Plan discount or allowed amount (the negotiated rate), Plan paid, Patient responsibility, and Reason / remark codes. If 'Plan paid' is $0 and there's a denial code, this is a denial - even if no separate letter arrived yet.

Denial codes hidden in your EOB

Codes like CO-50 (not medically necessary), CO-197 (no prior authorization), CO-29 (timely filing), or PR-1 (deductible) tell you why a claim was reduced or denied. Look them up - the same appeal rights apply whether the denial is on a formal letter or buried in your EOB.

What you actually owe

Wait for the matching bill from the provider before paying anything. Compare patient responsibility on the EOB to the bill. If they don't match, call the provider's billing office - providers cannot charge you more than the EOB's patient responsibility for in-network covered services.

When to appeal an EOB

If a claim was denied or partially paid and you believe it shouldn't have been, you have appeal rights even though the EOB isn't a formal denial letter. Your deadline still starts on the EOB date for most commercial plans.

Saw a denial code on your EOB?

Paste the EOB or the linked denial letter into the decoder and we'll explain what the code means and how to appeal.

Decode my letter

Informational only - not legal advice.