Understanding Your Explanation of Benefits (EOB)

If you have health insurance, you have probably received a document called an Explanation of Benefits, or EOB. It arrives after a doctor visit, lab test, or procedure, and it is one of the most confusing documents in healthcare.

Here is the important thing to know upfront: your EOB is not a bill. It is a summary from your insurance company showing what was charged, what they paid, and what you may owe. Understanding your EOB is the first step toward catching billing errors and avoiding overpayment.

What Is an EOB?

An EOB is a statement your health insurance company sends you after they process a claim from a healthcare provider. It explains:

• What service you received
• What the provider charged
• What your insurance plan's negotiated rate is
• What your insurance paid
• What you are responsible for paying

You should receive an EOB for every claim your insurer processes, whether you owe anything or not.

Key Terms on Your EOB

Here are the most important terms, explained in plain language:

Amount Billed (or Provider Charges)

This is the full price the provider charged before any insurance discounts. This number is almost always higher than what anyone actually pays. Think of it as the "sticker price."

Allowed Amount (or Negotiated Rate)

This is the price your insurance company has agreed to pay for the service. It is usually much lower than the amount billed. This is the number that matters — your cost share is calculated from this amount, not the full charge.

Plan Paid (or Insurance Payment)

This is the portion your insurance company paid directly to the provider.

Deductible

The amount you must pay out of pocket before your insurance starts paying. If your EOB shows charges applied to your deductible, it means you have not met your annual deductible yet.

Copay

A fixed dollar amount you pay for certain services (like $30 for a specialist visit). This is set by your plan and does not change based on the cost of the service.

Coinsurance

A percentage of the allowed amount that you pay after meeting your deductible. For example, if your plan has 20% coinsurance and the allowed amount is $1,000, you would pay $200.

Patient Responsibility

The total amount you may owe the provider. This is the number to compare against any bill you receive.

How to Read Your EOB Step by Step

1. Check the date of service — Make sure it matches an appointment or procedure you actually had.
2. Verify the provider name — Confirm you actually saw this doctor or visited this facility.
3. Look at the service description — Does it match what was done? If a routine checkup shows up as a surgical procedure, something is wrong.
4. Compare the allowed amount to the billed amount — The allowed amount should be lower. If they are the same and the number seems high, your provider may not be in-network.
5. Check your patient responsibility — This is what you should expect to see on your actual bill. If the bill is higher than this number, dispute it.
6. Look for claim denials — If any line items show "denied" or "not covered," check the reason code. Many denials are due to coding errors that can be corrected.

Common EOB Red Flags

Watch for these issues that may indicate an error:

• Services you did not receive appearing on the EOB
• Duplicate charges for the same service on the same date
• Out-of-network charges when you went to an in-network provider
• Preventive services not covered at 100% when the ACA requires them to be (for ACA-compliant plans)
• Patient responsibility higher than your out-of-pocket maximum — once you hit your annual out-of-pocket max, your plan should cover 100%

What to Do if Something Looks Wrong

If you spot an error on your EOB:

1. Call your insurance company using the number on the back of your insurance card
2. Reference the specific claim number and date of service
3. Ask them to explain any charges or denials you do not understand
4. If there is a coding error, ask the provider's billing department to resubmit the claim with the correct code

How Lysco Can Help

Reading an EOB should not require a medical billing degree. Lysco can analyze your EOB and translate every line item into plain language, flagging potential errors and overcharges. Upload your EOB at lysco.com to get a clear breakdown of what you were charged, what you actually owe, and whether anything looks wrong.

Sources: Centers for Medicare & Medicaid Services (CMS) Glossary, Affordable Care Act preventive services requirements (42 USC 300gg-13), Healthcare Financial Management Association.