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Sample Letter Disputing Balance Billing and Surprise Out-of-Network Charges

Last reviewed 2026-11-02 · Sample letters

Short answerA balance billing dispute letter states that you received a bill for the difference between the provider's charge and what your insurer paid, explains why you believe federal or plan rules limit that amount, and asks for a corrected bill within 10 business days. Attach your EOB and the bill, and cite only rules that fit your situation.

When does this letter apply?

Balance billing means a provider bills you for the gap between its full charge and the amount your insurer allowed. It is not always improper. Some out-of-network providers may bill that gap when you chose them knowingly.

This letter fits two common patterns under the No Surprises Act: out-of-network emergency care, and non-emergency care from an out-of-network provider at an in-network facility, such as an anesthesiologist, radiologist or pathologist, when you did not give proper notice and consent.

What the federal law does and does not cover

The No Surprises Act protects people with most private health plans, including employer and marketplace coverage. It does not apply to Medicare, Medicaid, TRICARE, VA or Indian Health Service coverage, which have their own rules.

Ground ambulance bills are not covered by the federal act, although air ambulance services are. If your bill is from a ground ambulance, delete the federal citations from the sample and rely on your plan terms and state resources instead.

Emergency services: cost sharing is generally limited to in-network levels
Out-of-network providers at in-network facilities: protected unless proper notice and consent was given
Medicaid: providers who accept it generally may not bill beyond the Medicaid payment and any allowed copay

How do you customize the letter?

Fill in the placeholders, then keep only the paragraph that matches your facts. Pull the numbers from your EOB: the allowed amount, what the plan paid, and your patient responsibility. If the provider's bill is higher than your patient responsibility, that difference is the heart of your dispute.

State whether the care was an emergency or took place at an in-network facility
Say whether you signed any consent form, and attach it if you have it
List the network status shown on your EOB
Name the amount you believe is correct, based on the EOB

What should you attach and where should it go?

Attach the bill, the EOB for the same date, and any consent paperwork. Send one copy to the provider's billing department. If your insurer processed the claim incorrectly, send a second note to the insurer asking it to reprocess it at in-network cost-sharing levels.

Keep proof of mailing. If you do not get a satisfactory reply, the CMS No Surprises Help Desk at 1-800-985-3059 can take complaints, and your state insurance department may also help.

What to expect

The letter asks for a written response in 10 business days. Possible outcomes include a corrected bill, a request for more documents, or a denial with an explanation. A denial is not the end: ask which rule the provider relies on, and take that to your insurer or regulator. Medical Bill Dispute Pro can generate a letter with the Reservation of Rights section already included, but you should review it before sending.

Sample letter

[YOUR NAME]
[YOUR ADDRESS]
[CITY, STATE ZIP]
[PHONE / EMAIL]

[DATE]

[PROVIDER NAME]
Attn: Billing Department
[PROVIDER BILLING ADDRESS]

Re: Dispute of balance bill
Patient: [PATIENT NAME]
Account number: [ACCOUNT NUMBER]
Date of service: [DATE OF SERVICE]
Amount billed to me: [AMOUNT]

To the Billing Department:

I am disputing the above balance. My health plan processed this claim, and the Explanation of Benefits shows a patient responsibility of [EOB PATIENT RESPONSIBILITY]. Your statement asks me to pay [AMOUNT], which exceeds that figure.

The care was [EMERGENCY CARE / SERVICES FROM AN OUT-OF-NETWORK PROVIDER AT AN IN-NETWORK FACILITY]. I did not knowingly choose an out-of-network provider and [DID NOT SIGN / DO NOT RECALL SIGNING] a notice and consent form. I believe the No Surprises Act, Pub. L. 116-260, including 42 U.S.C. § 300gg-111 and 42 U.S.C. § 300gg-112 where applicable, limits what I may be charged to in-network cost-sharing amounts.

I request that you:

1. Review the account and confirm the network status used to bill it.
2. Remove any amount above my in-network cost sharing and send a corrected statement.
3. Provide copies of any notice and consent documents you believe I signed.
4. Hold the account, and do not refer it to collections, while this is reviewed.

I have enclosed the statement and my EOB. Please respond in writing within 10 business days of receiving this letter.

If this is not resolved, I reserve the right to contact my health plan, the CMS No Surprises Help Desk, and my state insurance department or attorney general.

Sincerely,

[YOUR NAME]
[YOUR PHONE NUMBER]

Replace every [BRACKETED] placeholder before sending, and keep a copy plus proof of delivery.

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Frequently asked questions

Is every out-of-network bill illegal?

No. Many out-of-network bills are lawful, especially when you knowingly chose an out-of-network provider. The No Surprises Act applies to specific situations, such as emergency care and certain services at in-network facilities. Check your EOB and any forms you signed before assuming a bill is improper.

What if I signed a consent form at the hospital?

Notice and consent under the law has requirements, and a form signed in a rush may or may not meet them. Ask for a copy of what you signed and the date you received it. Note that emergency services generally cannot be waived this way.

Do I pay the provider or my insurer?

Pay only what your EOB lists as patient responsibility, once you are sure it is correct. A balance bill beyond that amount is what you dispute. If the insurer's own processing looks wrong, ask it to reprocess the claim.

Does this work for Medicare patients?

The federal No Surprises Act does not apply to Medicare, so remove those citations. Review your Medicare Summary Notice and contact Medicare using the claims and appeals page at medicare.gov to see what your provider may bill.

Who do I complain to if the provider ignores me?

Start with the CMS No Surprises Help Desk for federally covered situations. Complaints about insurer processing can go to your state insurance department, and billing practices of providers may go to your state attorney general's consumer protection office.

Sources and further reading

Not legal or medical advice. Medical Bill Dispute Pro is a software tool that helps you prepare billing dispute letters. It is not a law firm, does not provide legal advice, and cannot guarantee any outcome. Laws and rules change and vary by plan and state; verify important details with the sources linked above, your insurer, or a qualified professional.