How to Fight a Surprise Medical Bill (No Surprises Act)

A plain-English guide to your federal protections against out-of-network surprise bills — and the exact steps to push back.

By the Fight Back editorial team · Banana Bay Press · Updated July 26, 2026

Don't pay a surprise medical bill on sight. Under the federal No Surprises Act, most emergency and out-of-network bills at in-network facilities are illegal beyond your normal in-network cost-sharing. Compare the bill to your plan's Explanation of Benefits, tell the provider it violates the Act, ask for a corrected bill, and file a complaint with the CMS No Surprises Help Desk if they refuse.

What the No Surprises Act protects

The No Surprises Act is a federal law that took effect on January 1, 2022. It shields patients with private insurance from most "surprise" or balance bills in situations where you had little or no ability to choose an in-network provider.

In the situations the law covers, you can only be charged your normal in-network cost-sharing — the same deductible, copay, or coinsurance you would pay for an in-network provider. The provider cannot bill you for the balance above that amount. Specifically, the Act protects:

• Emergency services. Most emergency care from out-of-network providers and facilities, including care at freestanding emergency departments and certain post-stabilization services.
• Out-of-network care at in-network facilities. When you go to an in-network hospital or ambulatory surgical center but are treated by an out-of-network provider — for example, an anesthesiologist, radiologist, or assistant surgeon you never chose.
• Air ambulance services. Most emergency transport by out-of-network air ambulance providers.

One important gap: ground ambulance rides are generally not covered by the federal law. A ground ambulance bill can still feel like a surprise, but the No Surprises Act usually does not ban it. Some states have their own protections, so it is worth checking with your state insurance department.

What counts as a surprise bill

A surprise medical bill is an unexpected charge from a provider who was out of network and whom you did not knowingly choose. Classic examples include an emergency room visit at an out-of-network hospital, or a planned surgery at your in-network hospital where the anesthesiologist or a lab happened to be out of network.

These bills often arrive as "balance bills" — the difference between the provider's full charge and what your insurer agreed to pay. Before the No Surprises Act, patients were routinely stuck with those balances, sometimes for thousands of dollars they had no way to avoid. Now, for the covered situations above, that balance billing is banned, and the provider must work out payment with your insurer instead of chasing you.

There is one narrow exception. For some non-emergency services, an out-of-network provider may ask you to sign a written notice and consent waiver that gives up your protections in advance. Emergency care generally cannot be waived. If you never signed a valid waiver — or were pressured into one at check-in — you likely keep your full protection.

What to do when you get one

If a bill looks larger than expected, slow down before you pay. Many surprise bills are sent in error and corrected once you push back. Work through these steps in order:

1. Don't pay right away. Paying a bill can be treated as agreeing to it. Confirm the charge is correct before sending any money.
2. Get your Explanation of Benefits (EOB). Your insurer's EOB shows what was billed, what the plan paid, and what you actually owe. Compare it line by line against the provider's bill.
3. Confirm it's a covered situation. Was it emergency care, or out-of-network care at an in-network facility? If so, you should only owe in-network cost-sharing.
4. Contact the provider's billing office. Say the charge appears to violate the No Surprises Act and ask for a corrected bill limited to your in-network cost-sharing. Keep notes: names, dates, and what you were told.
5. Call your insurer too. Ask them to reprocess the claim at the in-network rate and confirm the correct amount you owe.
6. Escalate if they refuse. If the provider or insurer won't fix it, file a complaint with the federal No Surprises Help Desk (below).

Good Faith Estimate & disputing the bill

If you are uninsured or paying out of pocket (self-pay), you have a separate protection: the Good Faith Estimate. Providers and facilities must give you a written estimate of expected charges before scheduled care, or when you ask for one.

If your final bill ends up being at least $400 more than the Good Faith Estimate for that provider, you can challenge it through the patient-provider dispute resolution process. A neutral third-party reviewer looks at the estimate and the actual charges and decides what you should pay. There is a deadline to start a dispute after the bill date, so act promptly and keep your estimate.

For insured patients facing a denied or underpaid claim rather than a balance bill, your path is usually an appeal instead. See our guide on how to appeal a denied health insurance claim.

How to file a complaint

If a provider, facility, or insurer won't follow the rules, you can escalate to the federal government. A complaint can trigger a review of your bill and, in many cases, gets an improper charge corrected or removed.

When you file, have your bill, your Explanation of Benefits, and any notes from your calls ready. The more clearly you can show the charge exceeds your in-network cost-sharing, the faster it can be resolved. You can also loop in your state's insurance department, which may enforce additional state-level protections that go beyond the federal law.

Surprise bills are common, but they are often beatable. Know which situations are covered, compare every bill to your EOB, and don't be afraid to escalate. For a step-by-step system to dispute denials and improper bills, see the Insurance Denial Appeal Kit or start with our free resources on the Fight Back home page.