Three documents, three jobs
After a US procedure, you will usually receive several documents, sometimes weeks apart. Each one answers a different question.
- Explanation of Benefits (EOB). Sent by your insurer after it processes a claim. It shows what the provider billed, what your plan allowed, what the plan paid, and what it says is your share. It is usually marked "this is not a bill."
- Summary statement. Sent by the provider. It often shows just a total, the insurance payments and a balance due. Many people pay from this, which is why errors survive.
- Itemized statement. Also from the provider, usually only on request. It lists every charge with a date, a code, a description, units and a price.
If you were uninsured or self-pay and scheduled the care in advance, there may be a fourth document: a Good Faith Estimate (CMS, 2021). It lists the expected items, services, codes and charges from each provider and facility. Keep it next to the bill.
Reading an EOB field by field
Layouts differ between insurers, but almost every EOB has the same core fields.
| Field | What it means | What to check |
|---|---|---|
| Patient, claim number, provider | Who was treated, the claim's ID, and who billed | That it is your claim, and a provider you actually saw |
| Date of service | When the service happened | That the dates match your visit or stay |
| Service or code | The billed service, often with a procedure code | That it matches what was done |
| Amount billed | The provider's charge | Useful for reference only, since it is rarely what anyone pays |
| Allowed amount | The most your plan recognizes for that service | For in-network care, your share is figured from this number |
| Plan paid | What the insurer paid the provider | Whether it is zero, and if so, why |
| Deductible, copay, coinsurance | How your share was calculated | Whether it matches your plan's terms and how much of your deductible you have met |
| Not covered or denied, with a reason code | Amounts the plan refused, and why | The reason code, which tells you whether an appeal or a corrected claim could fix it |
| Network status | Whether the provider is in network | An out-of-network flag can explain a large balance |
| Patient responsibility | What the plan says you owe | This, not the billed amount, is the number your bill should match |
Reading an itemized statement
An itemized statement is where errors and surprises show up. Look at each line for:
Dates
Every line should fall within your actual stay or visit. A charge dated the day after discharge needs explaining.
Codes and descriptions
Procedure codes (CPT or HCPCS) identify professional services, supplies and drugs. Hospital bills also use revenue codes that group charges by department, such as pharmacy, operating room or recovery. Look up any code you don't recognize, and ask the billing office what it means.
Units and quantities
A medication billed 10 times when you received it once, or operating room time billed in more units than your surgery took, is a common place for mistakes.
Duplicates and canceled services
Look for the same charge listed twice, or a test that was ordered and then canceled but still billed.
Facility versus professional charges
The hospital or surgery center bills for the facility. The surgeon, anesthesiologist, radiologist and pathologist often bill separately. A missing professional bill is not good news. It may simply not have arrived yet.
Vague lines
Entries like "miscellaneous supplies" or "general pharmacy" should be broken down. Ask what each one contains.
Matching the EOB to the bill
The core check is simple: for each claim, the provider's balance should equal the patient responsibility on the EOB, minus anything you have already paid. Do it in this order:
- Wait for the EOB before paying any large balance, unless the provider is pursuing you and your insurer confirms the claim is final.
- Line up each EOB claim with the matching provider bill, using the date of service and the provider name.
- Compare the patient responsibility with the balance due. If the bill is higher, ask the provider why. Billing above the allowed amount can be a sign of an out-of-network or processing problem.
- If the EOB shows a denial, read the reason code. It may be a missing prior authorization, a coding error or a coverage exclusion. If it's a denial you want to fight, the steps are in insurance denied your procedure: now what?
- Ask for the itemized statement whenever the totals don't make sense, then work through it with the six checks above.
Self-pay and the $400 rule
If you were uninsured or self-pay and received a Good Faith Estimate, compare the bill with it. If the billed charges are at least $400 more than the estimate for any one provider or facility, you can start the federal patient-provider dispute process. The notice must go in within 120 calendar days of receiving the first bill, and there is a $25 administrative fee (CMS, 2021).
Keep a paper trail while you sort it out
Billing problems are usually solved by persistence and records, not by one phone call. While a bill is being reviewed:
- Log every call. Write down the date, the person you spoke with, what they said and any reference number you are given, so you can point back to the call later.
- Put disputes in writing. A short letter or portal message that lists the lines you are questioning, and why, is harder to lose than a phone conversation.
- Ask for the account to be put on hold. While a claim is being reprocessed or appealed, ask the provider to pause collection activity on the disputed amount, and confirm in writing whether they agreed.
- Pay what is clearly owed. If part of the balance is not in dispute, paying that part can show good faith while you resolve the rest.
Keep the EOB, the itemized statement, any Good Faith Estimate and your notes in one folder per episode of care. You will need the same folder if you later compare the cost with care somewhere else.
Turning your bill into a comparison number
If you are pricing the same care elsewhere, in another US setting or abroad, the bill is only useful once it is reduced to the right number.
- Use what you owe, not what was billed. For insured care, that is the sum of patient responsibility across every EOB for the episode: facility, surgeon, anesthesia, pathology, imaging and follow-up. For self-pay care, it is the sum of all Good Faith Estimates or the final negotiated bills. The difference between these figures is explained in chargemaster vs cash price vs negotiated rate.
- Group the lines by category. Surgeon, anesthesia, facility and nights, implants or devices, tests, medications, follow-up. A bundled quote from abroad can then be checked category by category. See bundled price vs itemized quote.
- Remember your plan year. If you have already met your deductible or out-of-pocket maximum, your real cost for more care this year may be much lower than a single bill suggests.
- Count the bills that haven't arrived. Professional bills often lag the facility bill by weeks. A comparison built from the first statement alone is too low.
The Takeaway
Treat the EOB as the insurer's version and the itemized statement as the provider's version. Pay only when they agree. When you compare care, compare your own share for the whole episode, not the largest number on the page.
Frequently asked questions
Is an Explanation of Benefits a bill?
No. An EOB is your insurer's record of how it processed a claim: what was billed, what the plan allowed and paid, and what it says you owe. The bill comes from the provider, and you should check that the two match before you pay.
What is the difference between the billed amount and the allowed amount?
The billed amount is the provider's charge. The allowed amount is the maximum your plan recognizes for that service. For in-network care, your share is calculated from the allowed amount, not the billed amount.
How do I get an itemized statement?
Call or write to the provider's billing office and ask for an itemized statement that shows dates, service codes, descriptions, units and charges for each line. Ask before paying a large balance.
What can I do if my self-pay bill is much higher than my Good Faith Estimate?
If the bill is at least $400 more than the estimate for any one provider or facility, you can start the federal patient-provider dispute process within 120 calendar days of receiving the bill. There is a $25 fee.
Which number should I compare with a medical quote from abroad?
Your realistic out-of-pocket cost: patient responsibility on the EOB if insured, or the Good Faith Estimate total if self-pay. A billed charge almost always overstates what you would really pay at home.