How to Dispute a Medical Bill (Step by Step, With a Sample Letter)

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By Qamar S, 15 years in US medical billing · Last reviewed September 24, 2026

To dispute a medical bill, first find out whether the problem is a billing error (fix it with the provider) or an insurance denial (appeal it with your insurer). Ask for an itemized bill, compare it with your EOB, call the billing office, and put your dispute in writing. You have 180 days from a denial notice to file an internal appeal with your insurer, and you can then ask for an independent external review.

Which path? Wrong charge, duplicate or service you didn’t get → dispute with the provider. Claim denied or paid less than expected → appeal with your insurer. Bill $400+ above your Good Faith Estimate (uninsured/self-pay) → federal dispute process. Surprise out-of-network bill → No Surprises Act.

Step 1: Gather your documents

  • the bill (ask for an itemized version with codes)
  • your insurer’s Explanation of Benefits
  • any Good Faith Estimate or price quote you received
  • notes of calls: date, name and what was said

Step 2: Find the problem

Common billing errors include:

  • duplicate charges for the same service
  • services, tests or supplies you didn’t receive
  • the wrong patient, date or insurance ID
  • a claim sent to the wrong insurer, or never sent at all
  • an office visit coded at a higher level than the visit you had

Step 3: Call the provider’s billing office

Be specific: “Line 4 on my itemized bill, dated [date], is a charge for [service] that I didn’t receive. Can you review and correct it?” Ask them to put your account on hold while they review, so it doesn’t go to collections.

From the billing side: the person who answers the billing phone can often fix a simple error on the spot, such as resubmitting to the right insurer or removing a duplicate. Ask for a “reference number” for your call and the name of the person helping you. If it isn’t resolved, ask for a supervisor or a “billing review.” Calm, specific requests get fixed faster than angry general ones.

Step 4: Put it in writing

If the call doesn’t fix it, send a short letter or secure portal message. Include your name, account number, date of service, the specific charges you dispute, why, and what you want (for example, “remove the duplicate charge of $250”). Keep a copy.

Step 5: Appeal an insurance denial

If your insurer denied or underpaid the claim:

  1. File an internal appeal within 180 days of the denial notice. Use the insurer’s appeal form or a letter, and include your doctor’s supporting notes.
  2. Know the timelines: insurers must decide standard appeals within 30 days for services you haven’t received yet and 60 days for services already received. Urgent appeals must be decided much faster (within 4 business days for expedited appeals).
  3. Ask for external review if the insurer still says no. Request it in writing within 4 months of the final denial notice. An independent reviewer decides, and the insurer no longer gets the final word.

See HealthCare.gov’s appeals guide for the official rules.

Step 6: Uninsured or self-pay? Use the $400 rule

If you received a Good Faith Estimate and your bill is at least $400 higher, you can start the federal patient-provider dispute process within 120 days of the bill date for a $25 fee. See our No Surprises Act guide.

Step 7: If the bill is in collections

Dispute it in writing with the debt collector within 30 days of their first contact and ask them to validate the debt. Collectors must stop collecting a disputed amount until they send verification.

Sample dispute letter

“Re: Account #[number], date of service [date]. I am disputing the following charges: [list]. Reason: [duplicate / not received / should be covered under my insurance, see attached EOB]. Please correct my account, send me an updated itemized statement and hold the account from collections while you review. Thank you, [name, phone].”

Frequently asked questions

How long do I have to dispute a medical bill?

There’s no single deadline for billing errors, but act quickly, before it goes to collections. For insurance denials, you have 180 days to file an internal appeal. For Good Faith Estimate disputes, 120 days from the bill date.

Can I refuse to pay a medical bill I think is wrong?

You can hold off paying the disputed part while it’s reviewed, but pay any amount you agree you owe and keep records.

Does disputing a bill hurt my credit?

No. Medical debt isn’t reported until it has been in collections for a year, and paid or under-$500 medical collections aren’t reported at all by the three major bureaus.

Sources

*This guide is educational and is not legal advice. See our Disclaimer.*