Field-by-Field Guide
How to Read an EOB
An Explanation of Benefits (EOB) is the statement your health insurer sends after processing a claim. Its most important property is what it is not: an EOB is not a bill. It explains what the provider charged, what the plan allowed and paid, and what portion — if any — may become your responsibility.
Every insurer designs its own EOB, but they all carry the same data: claim identification, the services on the claim, and a money trail from billed charge to patient responsibility. Learning to follow that trail is the whole skill.
Every section of an EOB, explained
Member and patient information
The subscriber (policyholder), the patient (which may be a dependent), member ID, and group number. Confirm the patient matches the visit — family plans generate EOBs for every member.
Claim number and dates
The insurer's claim identifier plus the date(s) of service and the date the claim was processed. The claim number is your reference for any call or appeal.
Provider information
The billing provider — which can be a physician group or facility whose name you don't recognize from the visit itself (labs and anesthesiologists bill separately).
Service lines and procedure codes
Each service on the claim as its own row, usually with a CPT/HCPCS procedure code and a short description, plus the quantity or units.
Billed amount (charges)
What the provider charged — the sticker price. Almost nobody actually pays this number; it is the starting point for the discount math.
Allowed amount
The negotiated rate the plan recognizes for in-network care. The difference between billed and allowed is the contractual adjustment the provider writes off.
Plan paid
What the insurer actually paid the provider from the allowed amount, after your cost-sharing is applied.
Deductible, copay, and coinsurance
Your cost-sharing, itemized: amounts applied to your annual deductible, fixed copays, and coinsurance (your percentage of the allowed amount after deductible).
Patient responsibility
The bottom line — what you may owe the provider: deductible + copay + coinsurance + any non-covered amounts. Compare this to the provider's bill before paying it.
Denial and remark codes
Claim adjustment reason codes (CARC) and remark codes (RARC) explaining reductions or denials — e.g., service not covered, authorization missing, duplicate claim. The code glossary is usually printed on the EOB itself.
Appeal information
Your appeal rights and the deadline for filing one. Appeal windows are finite — a missed EOB can mean a missed appeal.
Accumulator totals
Many EOBs show your year-to-date progress toward the deductible and out-of-pocket maximum.
How to read an EOB, step by step
- 1
Confirm this is your claim
Match the patient, provider, and date of service against a visit you actually had.
- 2
Follow the money trail per line
Billed → allowed → plan paid → your share. Each service line has its own trail; the totals sum them.
- 3
Understand every reduction
Any difference between allowed and paid should be explained by your deductible, copay, coinsurance, or a coded denial. Look up each code in the glossary.
- 4
Compare with the provider's bill
The bill's "patient balance" should match the EOB's patient responsibility. If the bill asks for more, call before paying.
- 5
Note appeal deadlines for denials
If anything was denied that you believe is covered, the clock on your appeal starts now.
Red flags worth a second look
- ⚠A provider bill that exceeds the EOB's patient responsibility.
- ⚠Services listed you don't recognize, or duplicate service lines for one visit.
- ⚠In-network care processed at out-of-network rates.
- ⚠Denial codes citing missing authorization for care that was pre-authorized.
- ⚠Balance billing of the billed-vs-allowed difference by an in-network provider — generally not permitted under network contracts.
What EOB Extractor extracts automatically
Once you know how to read an EOB, you also know how tedious it is to copy the values out by hand. EOB Extractor extracts these fields as structured data in seconds:
- ✓Patient & provider name
- ✓Claim number
- ✓Service date
- ✓Procedure (CPT) codes
- ✓Billed vs allowed amount
- ✓Insurance paid
- ✓Patient responsibility
- ✓Denial codes
FAQ
Is an EOB a bill?
No. It is the insurer's explanation of how a claim was processed. The bill comes from the provider — and its amount should match the EOB's patient responsibility.
What is the difference between billed and allowed amounts?
Billed is the provider's charge; allowed is the plan's negotiated rate for that service. In-network providers write off the difference as a contractual adjustment.
Why do I owe money when I have insurance?
Cost-sharing: amounts applied to your deductible, fixed copays, and coinsurance percentages are yours to pay until you hit the plan's out-of-pocket maximum.
What do the denial codes on my EOB mean?
They are standardized claim adjustment reason codes explaining why something wasn't paid — the EOB's glossary decodes them. Common ones cover non-covered services, missing authorizations, and duplicate claims.
Can I extract EOB data automatically?
Yes — upload the EOB and the parser returns claim numbers, service codes, billed/allowed/paid amounts, patient responsibility, and denial codes as structured data, from any insurer's format.