What is an Explanation of Benefits (EOB)?
An Explanation of Benefits (EOB) is a document your health insurance company sends you after a medical service is processed through your plan. It is not a bill — it is a summary of what happened when your provider submitted a claim to your insurer.
The EOB tells you three critical things:
- What the provider charged for the service
- What your insurance company agreed to pay (and actually paid)
- What you are responsible for paying out of pocket
You should receive an EOB for every medical claim — office visits, lab work, imaging, hospital stays, prescriptions (sometimes), and procedures. Most insurers now send EOBs electronically through their member portal, though you can request paper copies.
Important: Your EOB is NOT a bill
Do not pay based on your EOB alone. Wait for the actual bill from your provider. Then compare the bill to the EOB — the “patient responsibility” amount on your EOB should match the bill. If it does not, something is wrong.
The anatomy of an EOB — section by section
While every insurer formats their EOB slightly differently, they all contain the same core sections. Here is what each one means:
Patient and plan information
Your name, member ID, group number, and the patient who received the service (which may be a dependent). Always check that this information is correct — a wrong member ID can cause claims to be denied or processed under the wrong person.
Provider and date of service
The name of the provider who delivered the service and the date it was performed. Verify the date matches your records. If you see a provider name you do not recognize, it may be a lab, anesthesiologist, or other specialist who was involved in your care.
Service description and procedure codes
A description of the service and the CPT (Current Procedural Terminology) code used to bill it. CPT codes are 5-digit numbers that identify specific medical services. If the description looks wrong — for example, a comprehensive evaluation when you had a brief follow-up — the provider may have upcoded the service.
Billed amount (provider charges)
This is what the provider charged for the service — the "sticker price." This number is often much higher than what anyone actually pays, because insurers negotiate discounted rates. Do not panic if this number is large.
Allowed amount (negotiated rate)
This is the key number. The allowed amount is the maximum your insurer has agreed to pay for the service based on their contract with the provider. If the provider is in-network, they have agreed to accept this amount as payment in full (minus your cost-sharing). The difference between the billed amount and the allowed amount is the "provider write-off" — you do not owe this.
Plan paid (insurance payment)
The amount your insurance company actually paid the provider. This is the allowed amount minus your cost-sharing (deductible, copay, coinsurance). If this shows $0, it may mean the service was applied to your deductible, was denied, or was out-of-network.
Your responsibility (patient owes)
This is what you owe. It is broken down into deductible (the amount applied to your annual deductible), copay (a flat fee per visit), and coinsurance (your percentage share of the allowed amount). This number should match the bill you receive from the provider.
Remarks and denial codes
If a claim was partially or fully denied, the EOB will include a remark code explaining why. Common codes include "not medically necessary," "prior authorization required," "service not covered," or "timely filing limit exceeded." If you see a denial code, refer to our appeal guide.
Upload your EOB — we will translate it for free
Lysco reads your EOB and gives you a plain English summary of what happened, what you owe, and whether anything looks wrong.
Translate your EOB — freeConfusing terms decoded
EOBs are full of jargon that makes them harder to understand than they need to be. Here are the most common confusing terms, explained:
What to check on every EOB
Is the patient information correct?
Wrong member ID or patient name can cause claims to be denied or applied to the wrong deductible.
Does the date of service match your records?
A wrong date can indicate a billing error or a duplicate claim.
Does the service description match what actually happened?
If the description does not match your visit, the provider may have used the wrong billing code (upcoding).
Is the provider listed as in-network?
If you went to an in-network provider but they are listed as out-of-network, the claim was processed incorrectly and you will be overcharged.
Does the "patient responsibility" seem right?
Compare it to your deductible status and plan coinsurance. If you have already met your deductible but the EOB applies the charge to your deductible, something is off.
Are there any denial codes or remarks?
If part of the claim was denied, read the remark code carefully. Many denials are for administrative reasons (wrong code, missing info) that can be corrected.
Does the EOB match the bill from the provider?
The amount on your bill should match the "patient responsibility" on the EOB. If the bill is higher, the provider may be billing you for the write-off amount, which you do not owe.
Confused by your EOB?
Upload it and we will translate it into plain English
Get Started FreeWhen to take action on your EOB
You should take action if you see any of these red flags on your EOB:
- A service you do not recognize or did not receive — this could be a billing error or even fraud. Contact your provider first to clarify.
- An in-network provider listed as out-of-network — call your insurer and ask them to reprocess the claim with the correct network status.
- A service denied as "not covered" that you believe should be covered — review your plan document and consider filing an appeal.
- A "patient responsibility" amount that is higher than what your plan terms should produce — check your deductible and coinsurance math.
- A bill from a provider that is higher than the patient responsibility on your EOB — you may be being billed for the provider write-off, which you do not owe for in-network services.
- Multiple EOBs for the same date and same service — this may indicate duplicate billing. Contact the provider to confirm.
EOB vs. bill: what is the difference?
People often confuse EOBs and bills because they arrive around the same time and contain similar information. Here is the key difference:
The rule is simple: always wait for the actual bill, then compare it to the EOB before paying. If the bill is higher than what the EOB says you owe, call the provider and ask why.
Quick reference: your EOB checklist
- 1Receive EOB — read it, do NOT pay it (it is not a bill)
- 2Verify patient info, provider name, and date of service
- 3Check that the service description matches what actually happened
- 4Confirm the provider is listed as in-network (if applicable)
- 5Note the allowed amount — this is the real price, not the billed amount
- 6Check the patient responsibility breakdown (deductible + copay + coinsurance)
- 7Read any denial codes or remarks — refer to our appeal guide if denied
- 8Wait for the actual bill from the provider
- 9Compare the bill to the EOB — they should match
- 10If they do not match, call the provider billing department before paying
Confused by your EOB?
Upload it and we will translate it into plain English
Get Started FreeGet our free Healthcare Savings Guide
Join thousands of patients fighting back against unfair medical bills.
Start Fighting Back — FreeDisclaimer: This guide provides general information about Explanations of Benefits. It is not legal or financial advice. Plan terms vary. For personal advice, talk to your insurer or a licensed professional.
Upload your EOB — we will translate it
Lysco reads your Explanation of Benefits and gives you a plain English summary of what happened, what you owe, and whether anything looks wrong.
Get Started FreeNo credit card required.