How to Dispute a Surprise Medical Bill Under the No Surprises Act

Information checked: 2026-09-09 · Maintenance label: Evergreen check

You went to an in-network hospital, and a bill arrived from someone you never chose. That is the situation the No Surprises Act was written for, and it has been in effect since 1 January 2022.

The protections are real but bounded. Knowing which bills are covered, and which route applies to your situation, is what turns the law into an actual reduction on an actual bill.

This guide covers what is protected, the separate route for uninsured patients, and how to complain.

Key takeaway

The Act protects against surprise out-of-network bills for emergency care, non-emergency care connected to a visit at an in-network hospital, and air ambulance services. Uninsured patients are entitled to a good faith estimate and can dispute a bill that exceeds it by at least $400. The federal help desk is 1-800-985-3059.

Table of contents

• What is protected
• If you are uninsured or paying yourself
• Working the bill before you dispute
• Escalating
• What the Act does not do
• Frequently asked questions
• Summary

What is protected

The No Surprises Act, effective 1 January 2022, shields consumers from unexpected out-of-network medical bills in three situations:

• Emergency room visits
• Non-emergency care related to a visit to an in-network hospital, which is the anaesthetist or radiologist you never chose
• Air ambulance services

Protection applies to most health insurance plans. The second category is the one that resolves the most bills, because it covers the providers who happen to be working at a facility you did choose.

Get help with a specific billCMS No Surprises Help Desk ›Federal help desk for surprise billing questions and complaints, reachable at 1-800-985-3059 with language support.

If you are uninsured or paying yourself

A separate protection applies. Providers must give a good faith estimate when services are scheduled at least three business days in advance, or whenever you request one.

If the final bill exceeds that estimate by at least $400, you may challenge it through the patient-provider dispute resolution process.

Two practical consequences. Always ask for a good faith estimate before a scheduled procedure, even if nobody offers one. And keep it, because without it you have no baseline to dispute against.

Working the bill before you dispute

1. Request an itemised bill and read every line.
2. Compare it against your explanation of benefits, if you are insured, and against the good faith estimate if you are not.
3. Identify whether the provider was in-network or out-of-network, and whether the facility was in-network.
4. Check whether the situation fits one of the three protected categories.
5. Put your dispute in writing to the provider's billing office, keeping copies and dates.

A surprising share of disputes resolve at this stage, because itemisation surfaces duplicated or miscoded charges without any formal process.

Escalating

If the provider does not resolve it, federal help is available. Complaints can be submitted through the No Surprises Help Desk, reachable at 1-800-985-3059, available seven days a week with language support, or online through the CMS medical bill rights pages.

CMS also publishes an action plan tool that identifies the appropriate next step for a specific billing situation, which is worth using before assuming which route applies to you.

Get help with a specific billCMS No Surprises Help Desk ›Federal help desk for surprise billing questions and complaints, reachable at 1-800-985-3059 with language support.

What the Act does not do

Being clear about the boundaries saves wasted effort:

• It does not cap what in-network providers charge for ordinary in-network care.
• It does not remove your deductible, copayment or coinsurance.
• It does not cover every ground transport ambulance situation, unlike air ambulance.
• It does not replace your plan's own appeals process for a denied claim, which is a separate route with its own deadlines.

If your problem is a denial rather than a surprise out-of-network charge, the plan's internal appeal and any external review are the relevant path, and those have deadlines worth checking immediately.

Frequently asked questions

What counts as a surprise bill?

An out-of-network charge you did not choose: emergency care, care connected to a visit at an in-network hospital, or air ambulance services.

Is ground ambulance covered?

The protections named for ambulance services concern air ambulance. Ground ambulance is treated differently, so check your specific situation rather than assuming coverage.

What is the $400 rule?

For uninsured or self-paying patients, a final bill exceeding the good faith estimate by at least $400 can be challenged through patient-provider dispute resolution.

Do I have to pay while disputing?

Raise the dispute in writing with the billing office and ask what happens to the balance during review. Do not assume silence protects you, and keep the correspondence.

Where do I complain?

The federal No Surprises Help Desk at 1-800-985-3059, or online through the CMS medical bill rights pages.

Summary

Check first whether your bill sits in one of the three protected categories, then work the itemised bill against your explanation of benefits or good faith estimate.

For uninsured patients the good faith estimate is the whole game, so request it before every scheduled procedure and keep it. Escalate to the federal help desk if the provider will not resolve it.