What Is an EOB (Explanation of Benefits)?

An explanation of benefits, or EOB, is a summary your health insurer sends after it processes a claim. It shows how the cost of your care was split between your plan and you. It is not a bill, and you do not send payment from it.

What an explanation of benefits is

After you see a doctor or visit a hospital, the provider sends a claim to your insurance company. Once the plan processes that claim, it sends you an explanation of benefits. The EOB lists the service, the date, the amounts involved, and how much of the cost the plan covered.

The most important thing to know is that an EOB is not a bill. It is a record of how your claim was handled. A separate bill comes from the provider, and that is the document that asks for payment. If the two do not agree, the EOB is your reference for what you actually owe.

When and how you get an EOB

You do not sign up for EOBs on their own. Your insurer sends one after it finishes processing a claim, so an EOB follows your care rather than coming before it. If you saw a doctor, had a test, or filled a prescription that ran through your plan, an EOB for that visit usually shows up within a few weeks.

How it arrives depends on your plan. Many insurers mail a paper EOB to the address on your account. Most also post the same document in your online member portal or app, often before the paper copy reaches your mailbox. If you have not seen one in a while, log in to your plan's website and look for a section called claims or explanation of benefits.

Timing varies. Some plans send an EOB within days of processing a claim, while others batch them and send less often. You may also receive a separate EOB for each claim, so a single visit that involved several providers, such as a hospital, a surgeon, and an anesthesiologist, can produce more than one. Reading each one, rather than assuming they all say the same thing, is the habit that catches problems early.

What each section of an EOB means

Most EOBs show the same four amounts for each service, and they tell a two step story. The first two amounts set the price. The last two split that price between you and your plan.

• Billed amount: the provider's full sticker charge for the service, before insurance. It is often the highest number on the page, but it is not what anyone actually pays.
• Allowed amount: the price your plan and the provider agreed on. The difference between the billed amount and the allowed amount is written off when the provider is in your network. Nobody pays that difference.
• Plan paid: the share of the allowed price your insurance pays to the provider.
• Your responsibility: the rest of the allowed price, which you owe. It comes from your copay, deductible, and coinsurance, and it is the number your bill should match.

Why doesn't insurance pay the whole allowed amount? Because your plan is designed so you cover part of the price yourself, through your copay, deductible, and coinsurance.

EOB vs bill: how to compare them

An EOB and a bill describe the same visit from two sides. The EOB comes from your insurer and reports how the claim was processed. The bill comes from the provider and asks you to pay. Because they come from different places, they do not always agree.

To compare them, find the same service and date on both. Then line up two numbers: your responsibility on the EOB, and the amount the bill asks you to pay. When your plan is working normally, those two numbers match. If the bill is higher than your responsibility, something is off, and it is worth looking into before you pay.

Mismatches matter because the billed amount is not what you owe. If a provider bills you the full charge instead of your responsibility, or bills you for the network write off, you could pay far more than your share.

Common errors an EOB can reveal

Reading your EOB next to your bill can surface mistakes that are easy to miss. Watch for these.

• Wrong codes A service coded as something more complex or different from what happened, which can raise the allowed amount and your share.
• Out of network surprises A provider you expected to be in network processed as out of network, which shifts more of the cost onto you.
• Duplicate charges The same service processed more than once on the same date, so you are asked to pay for it twice.

What to do when your EOB and bill do not match

If the numbers do not line up, a calm and organized approach usually sorts it out. If your provider only sent a summary, ask for an itemized bill so you can match each charge to the EOB.

1. Put the EOB and the bill next to each other and match them by service and date.
2. Compare your responsibility on the EOB to the amount the bill asks for. Note every line where the bill is higher.
3. Call the provider billing office and ask them to rebill the account to match the EOB. Providers are supposed to bill you your responsibility, not the full charge.
4. If the EOB itself looks wrong, for example a wrong code or an out of network entry you did not expect, call your insurer and ask for a review or an appeal.
5. Keep notes of every call, including the date, the name of the person, and what was said, and keep copies of both documents.

Comparing an EOB and a bill line by line takes patience, and the codes are not written for patients. That is the part MedAdvocate can help with.

Why you might get an EOB when you did not see a doctor

Sometimes an EOB shows up for care you do not remember getting. That is worth a closer look, because it means a claim was filed under your name and your insurance details.

The most common reason is a simple billing error. A provider or their billing service can enter the wrong member number, mix up two patients with similar names, or submit a claim for the wrong date. These are usually cleared up with one call to the provider and, if needed, your insurer.

A less common but more serious reason is medical identity fraud. If someone uses your name and insurance to get care or supplies, the claim runs through your plan and an EOB lands with you. The service on it will be one you never received, sometimes at a provider you have never visited. Left unnoticed, it can drain your benefits and leave wrong information in your medical record. If you confirm a charge is fraud, you can also report it to the Federal Trade Commission at identitytheft.gov, which lays out the steps to limit the damage.

Checking every EOB is how people catch both. When a document lists a service, a date, or a provider that does not match your care, call your insurer to ask about the claim, and ask them to open a review if the charge is not yours. The same careful reading that catches a billing error also catches fraud, which is why it helps to open each EOB and each bill rather than setting them aside. If an unpaid bill is heading toward a collector, you still have time and clear rights; here is what to know about medical bills and collections.