The No Surprises Act: your federal protections against balance billing.
The federal No Surprises Act (NSA), effective January 1, 2022, bans most surprise medical bills. If you go to an in-network hospital and get treated by an out-of-network anesthesiologist, or you're rushed to any ER, you only owe your in-network cost-sharing — balance bills above that are illegal. Here's exactly what's covered, the major gaps, and how to dispute a violation.
What the NSA bans
Three specific situations:
- Emergency services at any hospital or freestanding ER — in-network or out-of-network, including stabilization care after the immediate emergency. You can only be charged your in-network deductible, copay, or coinsurance.
- Non-emergency care at an in-network facility delivered by an out-of-network provider you didn't choose — the classic "I went to an in-network hospital but the anesthesiologist / radiologist / pathologist / assistant surgeon was OON" scenario.
- Air ambulance — both fixed-wing planes and helicopters.
In all three, the provider must accept your in-network cost-sharing as full payment from you. The dispute over the OON amount above that is between the provider and your insurer (settled via federal independent dispute resolution, IDR).
What the NSA does NOT cover
- Ground ambulance. The single biggest gap. Federal NSA doesn't apply. Some states (CO, IL, MD, NJ, NY, OH, VT, VA, WV, FL, ME) have their own ground-ambulance balance-billing protections; most don't. A typical ground ambulance ride is $500-$3,000 with potential balance bill on top.
- You choose OON knowingly for non-emergency, non-ancillary care AND sign a notice-and-consent form 72+ hours before the appointment.
- Uninsured / self-pay patients. Different protection: you're entitled to a "Good Faith Estimate" in writing at least 3 days before scheduled care; if the actual bill is $400+ above the estimate, you can dispute via the federal Patient-Provider Dispute Resolution process.
- Cosmetic procedures, dental, and vision (when not part of essential medical care).
How to know if your bill violates NSA
Check the Explanation of Benefits (EOB) from your insurer alongside the provider's bill:
- EOB lists provider as out-of-network for a service at an in-network hospital, OR for an ER visit anywhere.
- Bill from provider exceeds what the EOB shows as your "patient responsibility."
- The difference is the suspected illegal balance bill.
If your insurer is paying based on the in-network rate but the provider is billing you the gap above that, the bill is likely an NSA violation.
Disputing a balance bill (step-by-step)
- Don't pay the disputed amount yet. Pay your insurer-stated patient responsibility (deductible / coinsurance / copay) so the account doesn't go to collections; dispute the rest.
- Call your insurer. Ask them to explicitly confirm the service is NSA-protected. Get the rep's name + reference number. Insurers are required to process NSA-protected claims at in-network cost-sharing.
- Send a written dispute to the provider's billing office. State that you believe the bill violates the No Surprises Act and request a corrected bill. Reference 45 CFR Part 149.
- File a federal complaint at 1-800-985-3059 or cms.gov/nosurprises/consumers/. CMS investigates and fines violators up to $10,000 per violation.
- File with your state insurance commissioner if your state has stronger protections.
- If sent to collections: dispute the debt under FCRA (Fair Credit Reporting Act). Recently-added CFPB rules also exclude medical debt under $500 from credit reports.
The Good Faith Estimate (uninsured / self-pay)
If you're paying cash, providers must give you a written Good Faith Estimate (GFE) at least 3 business days before scheduled care. If the actual bill exceeds the GFE by $400+, you can dispute it through the federal Patient-Provider Dispute Resolution (PPDR) process.
- Submission fee: $25 (refunded if you win).
- Decision timeline: 30 days.
- If you win, the provider can only collect the original GFE amount.
Always request the GFE in writing. Save the document. Even if you don't dispute, the GFE forces the provider to publish their actual cash price upfront.
Useful resources
- CMS No Surprises Act portal — federal source-of-truth, dispute submission
- CFPB medical billing & collections — debt-collection rights
- Dollar For — nonprofit that helps file charity care applications for free
- Patient Advocate Foundation — case-management help for billing disputes
Bottom line
Most "surprise" medical bills people see in their mailbox in 2026 are either NSA-protected or eligible for the Good Faith Estimate dispute process. Disputing works far more often than people expect — CMS reports billions in balance-bill exposure already reversed since 2022. Don't ignore the bill, don't auto-pay it, and don't assume "this is just what it costs." Verify against the EOB and dispute through the federal portal.
Reference information only — not legal advice. For a specific bill dispute, consult a licensed patient-advocacy organization or attorney. Last updated May 2026.