Explanations of benefits arrive looking like bills, are frequently printed like bills, and cause people to pay amounts they do not owe. Most carry a line saying "this is not a bill" somewhere on the page, usually in smaller type than the number that alarmed you.
What it actually is: your insurer's record of how it processed a claim. Read alongside the provider's itemised bill, the two documents give you an accurate picture of what care cost and what portion is genuinely yours. Read alone, either one misleads.
What this guide covers
- An EOB is a processing record, not a demand for payment
- Billed is the list price; allowed is the negotiated rate
- The contractual adjustment is written off, not owed by anyone
- Patient responsibility is the figure to compare against the provider bill
- Remark codes explain every reduced or denied line - look them up
- Reconcile the EOB and the bill before paying anything
The columns
Layouts differ between insurers but the same quantities appear on nearly all of them.
Amount billed / charged. What the provider asked for. This is a list price and is rarely what anyone pays.
Allowed amount / plan rate. The maximum the plan recognises for that service. For an in-network provider this is a contracted rate agreed in advance.
Contractual adjustment / discount / not covered by plan. The difference between billed and allowed. Where the provider is in network, this is written off under their contract with the insurer. Nobody pays it - not you, not the plan. This column is the source of most confusion.
Plan paid / insurance paid. What the insurer actually sent the provider.
Deductible. The portion applied against your annual deductible before the plan starts paying.
Copay / coinsurance. Your fixed fee or your percentage share of the allowed amount.
Patient responsibility / you may owe. The total the plan says falls to you. This is the number that matters, and the one to compare against what the provider bills.
A worked example
| Column | Amount |
|---|---|
| Billed | 2,480.00 |
| Allowed | 1,310.00 |
| Contractual adjustment | 1,170.00 |
| Plan paid | 1,048.00 |
| Deductible applied | 0.00 |
| Coinsurance | 262.00 |
| Patient responsibility | 262.00 |
The provider asked for $2,480. The contracted rate is $1,310. The $1,170 difference is written off. The plan paid 80 per cent of the allowed amount and $262 falls to you.
If a bill then arrives for $2,480, or for $1,218, something is wrong and it is worth a phone call before a payment.
Remark codes
Every reduced or denied line carries a short code explaining why. The key is usually printed on the reverse of the statement or available in the insurer's portal.
Common categories:
- Applied to deductible - covered, but you are paying because the deductible is not met.
- Not a covered benefit - the plan excludes this service.
- Requires prior authorisation - approval was needed and not obtained.
- Duplicate claim - submitted twice.
- Additional information needed - the insurer is waiting on the provider.
- Out of network - processed at a lower level or not at all.
The distinction that matters is administrative versus coverage. A missing prior authorisation or a duplicate submission is usually fixable by the provider resubmitting. A benefit exclusion is a coverage decision, and challenging it means the appeal process. The claim denial guide covers how to structure that, and the appeal deadlines guide covers the timeframes involved.
Reconciling against the bill
The EOB and the provider bill answer different questions and only make sense together.
Request an itemised bill from each provider - not a statement showing a balance. An itemised bill lists each service with its code, date and individual charge, which is what lets you match lines to the EOB. The itemised bill guide covers how to request one and what the columns mean.
Then build a table with one row per service date:
| Date | Provider | Billed | Allowed | Plan paid | You paid | Outstanding |
|---|---|---|---|---|---|---|
| 14 Mar | City ED | 2,480.00 | 1,310.00 | 1,048.00 | 262.00 | 0.00 |
| 22 Mar | Imaging | 640.00 | 395.00 | 316.00 | 79.00 | 0.00 |
An hour of this produces an accurate out-of-pocket figure. It also surfaces the discrepancies worth querying.
Working through an EOB
Confirm it says 'this is not a bill'
Almost all do, usually in small type.
Check the patient name, date of service and provider
Claims are occasionally processed against the wrong patient.
Note the claim number
Quote it in any query to the insurer or provider.
Identify the patient responsibility figure
This is the number to compare against the provider bill.
Ignore the contractual adjustment
In network, nobody pays it. It is a write-off.
Look up the remark code on every reduced or denied line
Key is on the reverse or in the insurer portal.
Separate administrative issues from coverage decisions
One is fixed by resubmission, the other needs an appeal.
Request an itemised bill from the provider
Not a statement showing a balance.
Build a reconciliation table, one row per service date
Billed, allowed, plan paid, you paid, outstanding.
Query differences in writing before paying
Reference the claim number and date of service.
Keep every EOB with the matching bill
Corrections and collection activity can surface late.
EOB layouts, terminology and remark code keys vary by insurer. Your own plan documents govern what is covered.
Why keep them
Beyond checking individual charges, EOBs are the only document showing what was actually paid rather than what was asked for. That matters in three situations.
Deductible tracking. They are the running record of how much of your annual deductible has been met.
Injury claims. Where treatment arises from an incident someone else may be responsible for, the accurate cost figure comes from the EOBs, not the billed amounts. The medical records organisation guide covers building that file.
Health insurer liens. Where a plan paid for treatment related to such an incident, it may assert a right to be repaid from any later recovery. The EOBs are what establish the amounts involved.
When to escalate
If a line is denied and the reason is a coverage decision you disagree with, that runs through the plan's appeal process rather than a phone call to billing. If a provider is pursuing a balance the EOB does not support, query it in writing and keep the correspondence.
Speak to a licensed attorney in your state if a large balance follows out-of-network care and you believe billing protections should apply, if a health insurer asserts a lien against a settlement, if an account has gone to collections and you dispute it, or if the amounts are significant. Your state department of insurance also accepts consumer complaints about claims handling at no cost. Questions about whether treatment was appropriate belong with your clinicians, not with a billing department.