Before you contact a provider or insurer, compare the itemized bill with the Explanation of Benefits (EOB) for the same date of service. The EOB is the statement your health plan issues after it processes a claim. It shows what was billed, what the plan allowed, what it paid, and what you may owe. Mismatches between the two documents can point to billing errors and show which amount is actually in question.
Check your bill and Explanation of Benefits first
Start by confirming that both documents cover the same care. Note the provider name, the date of service, and the claim reference number, then match each bill line to its EOB entry. Reading line by line takes longer than checking totals, but totals can hide offsetting errors.
Matching EOB amounts to provider charges
For each service, compare three figures: the amount the provider billed, the allowed amount the plan treats as payable under its contract, and the amount the plan paid. If the amount the provider asks you to pay is higher than the patient responsibility on the EOB, or the bill lists a service with no matching EOB line, mark that line for follow-up.
| Error type | What to look for on the EOB |
|---|---|
| Duplicate charge | The same service and date appear twice on the bill, but only once on the EOB |
| Wrong date | The bill’s date of service differs from the EOB’s date of service |
| Uncovered service | The EOB shows the service as not covered, yet the bill still charges you for it |
Patient responsibility versus insurer-paid amounts
Your patient responsibility on the EOB covers your deductible, copayment, or coinsurance for covered care. As a check, subtract the insurer-paid amount from the allowed amount and compare the result with the patient-responsibility line on the EOB and with the amount the provider bills you. If they do not match, ask the provider and the insurer to explain the gap before treating it as an error.
If a bill for emergency care, or for certain out-of-network care at an in-network facility, asks for out-of-network amounts, flag it, because you generally owe only in-network cost-sharing in those situations.
How do you request an itemized medical bill?
An itemized bill lists every service, supply, and charge that a provider billed to you, one line at a time. A summary statement shows only the total balance due. To get an itemized bill, ask the provider’s billing office in writing and identify the account by patient name, date of birth, account or claim number, and dates of service. Most billing offices can generate an itemized version from their own system, so this is usually a routine administrative request.
| Feature | Summary statement | Itemized bill |
|---|---|---|
| Content | Total balance, provider name, account number | Each charge listed separately |
| Service detail | Usually none | Procedure code, date, units, and charge per line |
| Use | Confirms the amount owed | Lets you match each line to care you received |
Each line of an itemized bill should show:
- CPT codes: the standard procedure codes that identify each service billed.
- Dates: the date each service was provided.
- Units: the quantity of each service or supply billed.
- Charges: the amount billed for each line, and the running total.
To make the request, follow these steps:
- Collect the identifiers listed above and the dates of the care you received.
- Send a written request to the billing office by the channel it accepts, such as a secure patient portal, email, or mail. State that you want an itemized bill showing all line items.
- Keep a copy of the request and note the date you sent it.
- When the bill arrives, check each line for dates you do not recognize, services you did not receive, and charges that appear more than once.
If the billing office is slow to respond, ask your plan or the CMS No Surprises Help Desk what other options exist. Keep the wording specific: name the account, the dates of service, and the document you want.
Contact the provider and insurer to dispute errors
Contact the provider’s billing office and the insurer’s member services line separately, and log every exchange. The provider controls the charges on the bill. The insurer controls what it paid and whether it considers a service covered. A dispute to one does not settle the other, so track each conversation in its own record.
Phone script
Before calling, have the account number, the date of service, the itemized bill, and any claim or explanation of benefits in front of you. Open by stating your name, the account number, and the specific charge you believe is wrong. Ask the representative to check that charge against the service record. Do not end the call without a stated next step and a timeline for it.
Reference numbers and call logs
Ask for a reference number at the start of each call, and note the name or employee ID of the person you speak with. Record the date, the time, the phone number, what was said, and what the representative agreed to do. This call log is the evidence you will rely on if the error is not corrected.
Written dispute letter
Follow each unresolved call with a written dispute letter, sent by a method that gives you proof of delivery. Structure it as follows:
- Your name, address, account number, and insurer member ID.
- The date of service and the exact charge in dispute.
- The reason you believe the charge is wrong, in one or two sentences.
- The correction you request, such as a revised itemized bill or a reprocessed claim.
- Prior contacts: dates, reference numbers, and names from your call log.
- Enclosures: copies only, never originals, such as the itemized bill, the explanation of benefits, and relevant records.
| Contact | What to request | What to keep |
|---|---|---|
| Provider billing office | Corrected itemized bill | Reference number, representative name, call log |
| Insurer member services | Claim review or reprocessing | Claim number, call log, copy of the letter |
Follow-up and escalation
Set a follow-up date before ending each call. If the correction has not appeared by then, call again and ask to speak with a billing supervisor, quoting your earlier reference numbers. Escalate in writing as well, attaching the letter and the log. If the insurer denies the claim, see ‘What if your insurer denies the claim?’ below. For questions about federal patient protections, the CMS No Surprises Help Desk can be reached at 1-800-985-3059, 8 am to 8 pm EST, seven days a week (CFPB, 2024-08-21).
What if your insurer denies the claim?
A denial is a decision by your health plan not to pay all or part of a claim. It is not the end of the process. The plan must give a reason, and that reason determines which appeal route applies. Under the rules summarized by the CFPB (2024-08-21), if your health plan denies a claim, you can appeal through the review process described in your plan documents. Those documents are the starting point for every step below.
Reading the denial reason. The denial notice or explanation of benefits lists one or more reason codes and, often, remark codes that explain each line item. Note the code next to each disputed charge, the service it refers to, and the amount denied. Some denials concern coverage, such as a service excluded by the plan. Others concern billing, such as a missing authorization or a coding issue. Each type is answered differently, so match your response to the specific code rather than writing a general objection.
Filing an internal appeal. Your plan documents set out how to file, where to send it, and the deadline. Deadlines and required forms are set by each plan, so confirm them in the documents and do not rely on general rules. Keep these items with your appeal:
- A copy of the denial notice and the claim number
- The itemized bill from the provider
- Any medical records or letters from your provider supporting the service
- A short written statement that names each disputed charge and the reason you disagree
Send the appeal by a method that gives you proof of delivery, and keep a copy of everything you submit.
External review. If the internal appeal is denied, your plan documents describe whether an external review by an independent reviewer is available and how to request one. Check the deadline and the steps in the same documents before you begin.
Can you dispute a bill if you are uninsured?
Possibly. The federal patient-provider dispute process run by CMS is available only if you meet specific conditions. The process applies if you had no insurance, or had insurance but did not use it for the care in question, and you told the provider before care that you were not using insurance. Both conditions must be met. Telling the provider afterward does not qualify.
Eligibility also depends on the estimate you received. You must have been given a good faith estimate before care. A dispute is possible only when one provider or facility billed at least $400 more than that estimate. A bill that exceeds the estimate by less than $400 does not qualify under this process.
The remaining conditions are about timing and cost:
| Requirement | Rule (CMS, 2026) |
|---|---|
| Bill date | The initial bill must be dated within the last 120 calendar days |
| Date of care | Care must have been received on or after January 1, 2022 |
| Administrative fee | $25, non-refundable |
To check eligibility, work through these steps in order:
- Find the good faith estimate and compare it with the total on the bill.
- Confirm that the difference is at least $400.
- Confirm that you told the provider in advance that you were not using insurance.
- Count 120 calendar days from the date printed on the initial bill.
- Confirm that the care was received on or after January 1, 2022.
The $25 fee must be paid before the dispute starts. No review begins until it is paid. If you win, the fee is deducted from what you owe, so you pay the balance rather than the fee on top of it.
Surprise billing and the No Surprises Act
The No Surprises Act protects insured patients from unexpected out-of-network charges in specific situations. For insured patients, these protections took effect on January 1, 2022. In covered situations, you generally owe only your in-network cost-sharing, meaning the deductible, copay, or coinsurance that applies under your plan, not the higher out-of-network rate.
| Situation | What you generally owe | Source |
|---|---|---|
| Emergency care | In-network cost-sharing only | CFPB, 2024-08-21 |
| Out-of-network care at an in-network facility | In-network cost-sharing only | CFPB, 2024-08-21 |
Emergency care
For emergency care, you generally owe only your in-network cost-sharing. When an emergency bill arrives, compare it with the explanation of benefits (EOB) from your health plan. The amount you are asked to pay should match your in-network cost-sharing, not an out-of-network charge.
Out-of-network care at in-network facilities
A hospital or facility can be in-network while an individual provider who works there, such as an anesthesiologist or radiologist, is not. For this situation, you generally owe only in-network cost-sharing. Check the provider’s network status on the bill or EOB, since the facility’s status alone does not settle it.
Provider notice and consent
For non-emergency care, the protections can depend on the situation and on any notice or consent form you are asked to sign, so confirm the details with your health plan or the CMS No Surprises Help Desk before agreeing to out-of-network charges. Before a scheduled procedure, ask the provider in writing whether they are in-network and whether you will be asked to accept out-of-network charges. Keep a copy of any notice or consent form you sign, because it is the record you will need if a bill later arrives at out-of-network rates.
Where to get help and file a complaint
The CMS No Surprises Help Desk is the federal contact for surprise billing questions. You can call 1-800-985-3059 from 8 am to 8 pm Eastern time, seven days a week. Have your bill, the provider’s name, and any claim numbers ready before you call so the representative can work from the same documents you do.
Other contacts depend on how your coverage is set up:
- Your health plan. Find the claims appeal section in your plan’s summary or member handbook, and keep a copy of every denial notice.
- State insurance department. Each state has an insurance department that accepts complaints about health insurers. Use it when the problem involves a coverage decision or claim handling and the plan’s internal appeal has not resolved it. Check the department’s website for its complaint form and required attachments. This guide does not list state-specific addresses, phone numbers, or deadlines.
- Your employer’s benefits office. If your coverage comes through a job, the employer benefits office or HR department administers the plan. It can explain how a claim was processed, provide plan documents, and confirm which appeal steps apply.
- Ombudsman and external review. Ask your plan or state insurance department whether an ombudsman program or external review applies to your plan type. The source material for this guide does not confirm which programs are available in each state, so verify this with the agency that regulates your plan.
Frequently asked questions
Does the federal dispute process cover my bill if I have health insurance?
Generally no. The process is for people who had no insurance or chose not to use it, and who told the provider before care. It also requires a good faith estimate and a bill from one provider or facility at least $400 above that estimate, dated within the last 120 calendar days.
What does the $25 dispute fee cover, and can I get it back?
The $25 administrative fee is non-refundable, and the dispute does not start until it is paid. If you win, the fee is deducted from what you owe. If you and the provider settle before the reviewer decides, the provider must reduce your bill by at least $12.50 and notify the reviewer.
Is the federal dispute process the same as appealing an insurer denial?
No. The dispute process is a CMS review of a provider bill, while a claim your health plan denies is handled through the appeal process described in your plan documents.
