Surprise billing at in-network hospitals means receiving a bill from an out-of-network doctor—typically an anesthesiologist, radiologist, pathologist, or emergency physician—who treated you at a hospital your insurance covers. This happens because these specialists are often independent contractors rather than hospital employees, and patients have no control over who works on them during surgery or emergency care.
Federal law has restricted most surprise bills since January 2022, but enforcement gaps mean thousands of patients still receive them. According to the Centers for Medicare & Medicaid Services, the No Surprises Act protects you from balance billing when out-of-network providers deliver services at in-network facilities. Getting that protection enforced requires knowing your rights and filing a complaint within a strict 120-day deadline.
Table of Contents
- How Often This Happens and How Much It Costs
- What the No Surprises Act Actually Protects
- Why Many Patients Still Struggle to Get Refunds
- How to File a Complaint and Claim Your Protection
- What to Do If You Have Already Paid
- Frequently Asked Questions
How Often This Happens and How Much It Costs
Out-of-network billing by specialists at in-network facilities is not rare. According to the Kaiser Family Foundation, one in five insured adults had an unexpected medical bill from an out-of-network provider in the past two years, and 18% of emergency department visits result in at least one surprise bill.
Anesthesia bills are particularly common: according to the American Society of Anesthesiologists, 11.8% of anesthesiology cases at in-network facilities generate out-of-network charges, with a mean balance of $2,130 per anesthesiologist. The problem hits hardest in emergency care, where you cannot shop for providers or refuse treatment. State-by-state rates vary significantly, so a routine surgery or emergency visit at a hospital you chose can trigger an unexpected bill depending on where you live.
What the No Surprises Act Actually Protects
The No Surprises Act, enacted in 2020 and effective January 1, 2022, bans most surprise bills at in-network hospitals and ambulatory surgical centers. The law applies to emergency services and to non-emergency specialty services (anesthesia, radiology, pathology, and other covered services) performed by out-of-network providers at in-network facilities.
Under the law, you pay only your normal in-network cost-sharing—the copay or coinsurance you would owe for an in-network provider. The protection works. According to the HHS Office of the Assistant Secretary for Planning and Evaluation, emergency services surprise bills dropped 24% by 2022, and non-emergency out-of-network bills at in-network facilities dropped 17% by 2022, compared to 2019 baselines. Without the law, surprise bills would be far more common.
Why Many Patients Still Struggle to Get Refunds
Legal protection and practical enforcement are not the same. According to the Georgetown University Center on health insurance Reforms, more than half (53%) of people who received surprise medical bills reported their issue was either unresolved or not resolved to their satisfaction, and 57% of those paid the bill in full despite the protections.
The federal Independent Dispute Resolution process, designed to arbitrate disagreements between patients and providers, has been overwhelmed: over 5 million disputes have been filed since April 2022, far exceeding initial projections and creating long delays. The June 2026 federal reforms addressed some bottlenecks by reducing arbitration fees from $115 to $15 per party per dispute and standardizing communication codes, but the backlog persists. A surprise bill may be illegal, but you still have to claim your protection and wait for the system to process it.
How to File a Complaint and Claim Your Protection
You have a 120-day deadline from the date of your first bill to file a complaint about a surprise bill. File through the Centers for Medicare & Medicaid Services at CMS.gov/nosurprises or by calling 1-800-985-3059. Include a copy of the surprise bill, proof that the facility was in-network, and your insurance information. Do not wait.
The 120-day window is strict—complaints filed after it expires are not accepted. If you have already paid the bill, filing a complaint starts the dispute resolution process that may force a refund. If you have not paid, filing prevents collection efforts and puts the burden on the provider to prove their claim.
What to Do If You Have Already Paid
If you paid a surprise bill without knowing about the law, you can still file a complaint within 120 days of receiving the original bill (not 120 days after paying). Include a copy of your payment proof in your complaint. The dispute resolution process can order a refund, though the timeline varies based on the system's current volume.
For uninsured or self-pay patients, the rules differ slightly: you have a separate good faith estimate dispute process. If a final bill exceeds a written estimate by 10% or more, you can dispute it under federal law.
Frequently Asked Questions
If I am uninsured, does the No Surprises Act apply to me?
No. The No Surprises Act applies to insured patients. Uninsured patients have a separate federal protection: the good faith estimate dispute process, which allows you to dispute final bills that exceed a written estimate by 10% or more.
Can I refuse treatment if the specialist is out-of-network?
In emergencies, no. In non-emergency cases at in-network facilities, the provider is required to disclose their network status before treatment when possible. If you are not told and later billed, the law protects you regardless.
What happens if I miss the 120-day deadline?
You lose the federal complaint window. The provider can send your bill to collections. However, you may still have state-level protections or remedies; contact your state's insurance commissioner's office to check.
How long does dispute resolution take?
The timeline varies widely due to current backlog. Some disputes resolve in weeks; others take months. The 2026 reforms are intended to speed the process, but there is no guaranteed timeline.