What Is an EOB (Explanation of Benefits)?

An explanation of benefits, or EOB, is a document your health insurance company sends after it processes a claim for your care. It shows what your provider charged, what your plan is willing to pay, and what you are responsible for. The single most important thing to understand is that an EOB is not a bill, per CMS^[1]. It is a statement of how your insurer handled the claim. The bill comes separately from your provider.

Why you get an EOB

An EOB is your plan's record of a claim. It is how you see, for every visit, test, or treatment, how much was billed, how much the plan paid, and how much, if anything, you still owe. It is also how the plan tells you what was applied to your deductible and out-of-pocket maximum.

The parts of an EOB

CMS lists the standard fields on an explanation of benefits (CMS^[1]):

The fields that matter most are the last four. Provider charges are the billed amount, which is often higher than the allowed amount the plan has agreed to. Paid by insurer is what the plan covered. What you owe is the remainder, which reflects your deductible, copay, or coinsurance.

EOB, bill, and itemized bill: three different things

These three documents arrive at different times and do different jobs, and people routinely confuse them.

• The EOB comes from your insurer and explains how the claim was processed. It is never a bill.
• The bill comes from your provider and states what they say you owe.
• An itemized bill is a line-by-line breakdown of every charge, which you can request from the provider to check for errors.

The sequence is: provider sends a claim to your insurer, the insurer sends you an EOB, and the provider sends you a bill. The EOB should arrive before or around the bill, and its "what you owe" line should match what the bill asks for.

How to read and check it

Follow the reading order CMS recommends (CMS^[1]):

1. Confirm the basics: you are the patient, and the provider and date of service match the care you actually received.
2. Read the cost fields: what was charged, what was allowed, and what the insurer paid.
3. Look at the "what you owe" line. This is your share, but it does not show whether you have already paid part of it.
4. Check the remark codes at the bottom; they explain why an amount was reduced or denied.
5. Compare the provider's bill to the patient balance on the EOB. Your bill should not be higher than that amount. If it is, call the provider.

A remark code is a two- or three-character note that explains something about the claim, such as why a service was not covered or why an amount was reduced. The bottom of the EOB has a description of each code, and reading them is how you know whether a denial is legitimately yours to pay or a mistake to appeal.

What to do if the EOB is wrong

If a claim looks wrong, such as a charge for care you did not receive, or an amount your plan says it will not pay when you think it should, call the number on the EOB and ask the plan to review it. You have the right to an internal appeal and an external review with your insurer, per CFPB^[2].

A bill that is higher than the EOB's patient balance is a common sign of a billing or coding error worth contesting before you pay.

EOB, deductible, and out-of-pocket progress

Because the EOB lists how much of each claim went to your deductible, copay, and coinsurance, a series of EOBs is how you track your progress toward your out-of-pocket maximum. Once those amounts reach the maximum, your plan pays 100% of covered in-network care for the rest of the plan year (HealthCare.gov^[3]).

Frequently asked questions

Is an EOB a bill? No. An EOB explains how your claim was processed. The bill comes from your provider (CMS^[1]).

How long after a visit do I get an EOB? You typically receive an EOB after your provider submits a claim, which can take days to weeks depending on the provider and plan. The timing varies by insurer.

Why does my EOB show more than my bill? The EOB shows provider charges and allowed amounts plus the plan's share. Your final provider bill reflects the patient balance, which is what you owe, and should not be higher than the EOB's "what you owe" line (CMS^[1]).

What if my bill is higher than the EOB says I owe? Contact the provider. Your bill should not exceed the EOB's patient balance, and a higher amount is worth questioning before you pay (CMS^[1]).

What if my EOB says a claim was denied? Read the remark codes to see why, then appeal if you believe it should have been covered. You have an internal appeal and an external review right (CFPB^[2]).

Do I need to keep my EOBs? It helps. EOBs are your record of what was paid and what was applied to your deductible and out-of-pocket maximum, which can settle disputes later.

What is the difference between an EOB and an itemized bill? An EOB is from your insurer and shows how a claim was processed. An itemized bill is from your provider and lists every individual charge. Request an itemized bill to check for errors on a large bill.

Why did I receive an EOB for care I do not remember? Check the date of service and provider. It may be a lab or imaging service billed separately from a visit you do remember, or a mistake worth flagging to your insurer.

This is patient education, not financial or legal advice. Reviewed October 3, 2026.

Sources

• CMS, How to read a health insurance explanation of benefits^[1]
• HealthCare.gov, Out-of-pocket maximum/limit^[3]
• CFPB, What should I do if I can't pay a medical bill^[2]