What is an explanation of benefits (EOB), and is it a bill?
An EOB comes from your health plan, a bill comes from your provider and, with Original Medicare, a Medicare Summary Notice comes from Medicare. They are different documents.
Arun Verma, co-founder of Triangle · 2026-10-17
This is not clinical evidence and not medical advice. It does not replace your care team. Discuss anything here with your clinician before you act on it.
What is an explanation of benefits (EOB), and is it a bill?
No, an EOB isn't a bill. It's the statement your health plan sends about a claim for your care, and CMS says it helps you understand how much your plan covers and what you'll pay when you get a bill from your provider. NAIC puts it as the insurer's explanation of how the costs of services are shared between you and the insurer. CMS's sample EOB is stamped "THIS IS NOT A BILL" near the top.
What's on an EOB?
An EOB names the patient, the plan and the provider, then lists each service with its date and its amounts. CMS's guide adds a claim number and a payee, who is the person reimbursed for any overpayments. Each claim line has a date of service and a service description, such as a medical visit. NAIC says it may show billing codes, and if it doesn't, there should be notes on how to get them if you want them. Not all EOBs look alike.
What do billed, allowed, paid and owed mean on an EOB?
On CMS's sample EOB the four amounts are labeled Provider Charges, Allowed Charges, Paid by Insurer and What You Owe. Provider Charges is the amount your provider bills for the visit. Allowed Charges is the amount the provider will be paid, which may not be the same figure. Paid by Insurer is what your plan will pay the provider. What You Owe, also called Patient Balance, is what's left after the insurer has paid everything else. The sample puts copay, deductible and coinsurance columns under "Your Responsibility." The allowed amount is the most a plan will pay for a covered service, HealthCare.gov's glossary says, and the same figure may be called "eligible expense," "payment allowance" or "negotiated rate." The glossary adds that if a provider charges more than the plan's allowed amount, you may have to pay the difference. NAIC says the allowed amount is negotiated between the provider and the insurer.
What do the codes and notes on an EOB mean?
CMS defines a remark code as a note from the health plan that explains more about the costs, charges and paid amounts for your visit. It's usually 2 or 3 letters and numbers, with a description of each code at the bottom of the EOB. In CMS's sample, the code PDC reads: "Billed amount is higher than the maximum payment insurance allows. The payment is for the allowed amount." For denials, NAIC says the insurer may use codes to explain the reasons, and the EOB should explain those codes. If a code isn't explained, you could ask the plan, whose number is on the EOB, what a code means.
How does the Medicare Summary Notice differ from an EOB?
Medicare sends the Medicare Summary Notice (MSN), while an EOB comes from your health plan. Medicare.gov describes the MSN as a notice, not a bill, that people with Original Medicare get in the mail for Part A and Part B services. It shows what providers billed Medicare, what Medicare paid and the maximum amount you may owe the provider. The labels differ. CMS's sample EOB has a What You Owe column. Medicare's sample Part B notice has Max You May Be Billed, which it defines as the total amount the provider is able to bill you. That notice also has an Approved column showing whether each claim was approved or denied. Which document your own coverage sends is a question for your plan or Medicare.
How do I compare an EOB with the provider's bill?
NAIC points to the owed amounts as the ones to compare. An EOB tells how much you owe each provider, and the amounts to set beside it are the bills from your providers and what you've already paid. An EOB only shows what you owe, not whether you've paid, so you may have already paid for part of the Patient Balance. Payments made directly to your provider may not be subtracted from that amount, the sample's notes add. CMS says a provider's bill should not be higher than the Patient Balance, and if it is, the provider is the one to talk to.
Who do I ask when the EOB and the bill don't match?
CFPB's guidance on medical bills points to the provider's billing office when you're unsure about a charge. The contact information is on the billing statement. Its list of questions to consider includes whether the charges reflect the services you received, whether they reflect the payment by your insurance, and whether any charge calls a service out-of-network when it wasn't. If something doesn't look right, you can ask for an itemized list of charges, CFPB says, and look for errors such as the same service charged twice. A fair question for the plan, whose number is on the EOB, is how a claim was processed.
Who gets an EOB, and what else is it useful for?
Usually the insurer sends it to the primary person on the health plan. When an employer provides the insurance, the employee usually receives the EOBs, including those for a spouse and dependents on the plan, NAIC says. CMS says you can use it to track how you and your family use your coverage. NAIC says an EOB helps you track how much you've spent out-of-pocket for covered health care costs, which helps you know how far along you are in meeting your deductible and out-of-pocket limit for the year.
What could I ask about an EOB I can't make sense of?
You could ask which service each line is for, whether the bill's total matches What You Owe, and whether your own payments have been counted. Those are questions for the plan and the provider named on the document. A page like this can't say what a particular EOB means for you.
Sources
- CMS: Reading Your Explanation of Benefits (EOB), printable sample (HHS Publication #11819) (p. 1): CMS's printable EOB guide says you may receive an EOB from your health plan after your visit with the provider, and that you may get a separate bill from the provider.
- CMS: Reading Your Explanation of Benefits (EOB), printable sample (HHS Publication #11819) (pp. 1-2): CMS's sample EOB carries the words "THIS IS NOT A BILL" near the top, and its claim table has a column headed "What You Owe" (printable guide, pp. 1-2).
- Medicare.gov: "Medicare Summary Notice" (MSN): Medicare.gov says the Medicare Summary Notice (MSN) is not a bill and is a notice people with Original Medicare get in the mail for their Medicare Part A and Part B-covered services.
- CMS: How to read a health insurance explanation of benefits: CMS says an explanation of benefits isn't a bill and helps you understand how much your health plan covers and what you'll pay when you get a bill from your provider.
- NAIC: Health Care Bills: Explanation of Benefits (consumer guide) (p. 1): NAIC says that after you receive medical care your health insurer will send you information about your claim in an EOB, that the EOB is not a bill, and that it is the insurer's explanation of how the costs of services are shared between you and the insurer.
- CMS: How to read a health insurance explanation of benefits: CMS says an explanation of benefits includes information about the patient, the health plan, who provided the care and when, a claim number and the payee, the person who gets reimbursed for any overpayments.
- CMS: How to read a health insurance explanation of benefits: CMS says an explanation of benefits gives claim details such as the date of service and a service description, which explains what service you had, like a medical visit.
- NAIC: Health Care Bills: Explanation of Benefits (consumer guide) (pp. 1-2): NAIC says not all EOBs look alike, that there also may be billing codes, and that if those aren't on the EOB there should be notes about how to get the codes.
- CMS: How to read a health insurance explanation of benefits: CMS says "Provider Charges" is the amount your provider bills for your visit.
- CMS: How to read a health insurance explanation of benefits: CMS says "Allowed Charges" is the amount your provider will be paid and may not be the same as the Provider Charges.
- CMS: How to read a health insurance explanation of benefits: CMS says "Paid by Insurer" is the amount your health plan will pay to your provider.
- CMS: How to read a health insurance explanation of benefits: CMS says What You Owe, or Patient Balance, is the amount you owe after your insurer has paid everything else.
- CMS: Reading Your Explanation of Benefits (EOB), printable sample (HHS Publication #11819) (p. 2): CMS's sample EOB groups Co Pay, Deductible and Coinsurance columns under "Your Responsibility" (printable guide, p. 2).
- HealthCare.gov Glossary: Allowed amount: HealthCare.gov's glossary defines the allowed amount as the maximum amount a plan will pay for a covered health care service, and says it may also be called "eligible expense," "payment allowance," or "negotiated rate."
- HealthCare.gov Glossary: Allowed amount: HealthCare.gov's glossary says that if your provider charges more than the plan's allowed amount, you may have to pay the difference.
- NAIC: Health Care Bills: Explanation of Benefits (consumer guide) (p. 2): NAIC says the allowed amount is the amount the insurer will pay the provider for the care you received and that it is negotiated between the provider and the insurer.
- CMS: How to read a health insurance explanation of benefits: CMS says a remark code is a note from the health plan that explains more about the costs, charges, and paid amounts for your visit; the code is usually 2 or 3 letters and numbers, and a description of each code is at the bottom of the explanation of benefits.
- CMS: Reading Your Explanation of Benefits (EOB), printable sample (HHS Publication #11819) (p. 2): CMS's sample EOB gives the remark code PDC as "Billed amount is higher than the maximum payment insurance allows. The payment is for the allowed amount." (printable guide, p. 2).
- NAIC: Health Care Bills: Explanation of Benefits (consumer guide) (p. 2): NAIC says the insurer may use codes to explain denial reasons and notes, and you should see an explanation of the codes on the EOB.
- CMS: How to read a health insurance explanation of benefits: CMS says the explanation of benefits lists your health plan's phone number.
- Medicare.gov: "Medicare Summary Notice" (MSN): Medicare.gov says the MSN shows all your services or supplies that providers and suppliers billed to Medicare during that period, what Medicare paid, and the maximum amount you may owe the provider.
- Medicare.gov: "Medicare Summary Notice" (MSN): Medicare.gov's MSN page lists Medicare as the sender of the MSN.
- Medicare.gov: Sample Part B Medicare Summary Notice, "What's in your Medicare Summary Notice?" (PDF p. 5): Medicare's sample Part B MSN says "Max You May Be Billed" is the total amount the provider is able to bill you.
- Medicare.gov: Sample Part B Medicare Summary Notice, "What's in your Medicare Summary Notice?" (PDF p. 5): Medicare's sample Part B MSN says its Approved column lets you know whether a claim was approved or denied.
- NAIC: Health Care Bills: Explanation of Benefits (consumer guide) (p. 1): NAIC says an EOB tells how much each provider charged, how much the health insurer paid, and how much you owe each provider, and to compare the "owed" amounts on the EOB with amounts on bills from your providers and what you've already paid.
- CMS: How to read a health insurance explanation of benefits: CMS says the Explanation of Benefits only shows what you owe, not if you've already paid for it, and that you may have already paid for part of the Patient Balance.
- CMS: Reading Your Explanation of Benefits (EOB), printable sample (HHS Publication #11819) (p. 2): CMS's printable guide says payments made directly to your provider may not be subtracted from the What You Owe amount.
- CMS: How to read a health insurance explanation of benefits: CMS says your bill should not be higher than the Patient Balance and, if it is, to talk to your provider.
- CFPB: What should I do if I can't pay a medical bill? (Ask CFPB): CFPB says that if you are unsure about a charge you can talk to the accounting or billing office of your provider, whose contact information will be on the billing statement.
- CFPB: What should I do if I can't pay a medical bill? (Ask CFPB): CFPB lists questions to consider when checking charges: whether the charges are accurate and reflect the services you received, whether the bills reflect the payment by your insurance and what the provider understood would be covered, and whether any charge shows a service as "out-of-network" when it wasn't.
- CFPB: What should I do if I can't pay a medical bill? (Ask CFPB): CFPB says that if something doesn't look right you can ask for an itemized list of charges, and to look for billing errors like being charged for the same service or treatment twice.
- NAIC: Health Care Bills: Explanation of Benefits (consumer guide) (p. 2): NAIC says that usually the insurer sends the EOB to the primary person on the health plan, and that when an employer provides the insurance the employee usually receives the EOB, including EOBs for a spouse and dependents on the plan.
- CMS: Reading Your Explanation of Benefits (EOB), printable sample (HHS Publication #11819) (p. 1): CMS's printable guide says you can use an EOB to track how you and your family use your coverage.
- NAIC: Health Care Bills: Explanation of Benefits (consumer guide) (p. 2): NAIC says an EOB helps you track how much you've spent out-of-pocket for covered health care costs, which helps you know how far along you are in meeting your deductible and out-of-pocket limit for the year.
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