What is a surprise bill?

A bill from an out-of-network provider — like an anesthesiologist — at a hospital that was in your network. You didn't choose that doctor, and since 2022 that bill is largely illegal.

What does the No Surprises Act cover?

Emergency services, out-of-network providers at in-network facilities, and air ambulances, for most health plans. You owe only your normal in-network cost-sharing.

What should I do if I get one?

Don't pay it right away. Tell the biller you believe it's a surprise bill under the No Surprises Act, and file a complaint at cms.gov/nosurprises if they won't fix it.

Your Rights Against Surprise Bills

You do everything right: you confirm the hospital is in your insurance network, you have the procedure, and then a bill arrives from an anesthesiologist or radiologist you've never heard of — out of network, for thousands of dollars. Since January 2022, federal law says that bill is largely illegal.

What the law covers

Emergency services. If your plan covers emergency care, it must cover it even at an out-of-network emergency room — no prior authorization required. This includes care after you're stabilized. Whether it counts as an emergency is judged by what a reasonable person would have believed at the time, not by the final diagnosis.

Out-of-network providers at in-network facilities. The classic surprise bill: your hospital is in network, but the anesthesiologist, radiologist, pathologist, or lab that treated you isn't. For these providers at in-network hospitals (and hospital outpatient departments and ambulatory surgical centers), balance billing is banned. Some of these specialists can't even ask you to waive the protection.

Air ambulances. Out-of-network helicopter or fixed-wing transport is covered — your cost can't exceed the normal in-network amount.

What you owe

When the law applies, you pay only your normal in-network cost-sharing: your copay, coinsurance, or deductible, as if everyone had been in network. Your health plan pays the out-of-network provider directly — the payment fight is between them, not you. And whatever you pay counts toward your deductible and out-of-pocket maximum.

The big gap: ground ambulances

The law does not cover the regular ambulance that drives you to the ER. Ground ambulance rides can still generate large out-of-network bills under federal law — some states have their own protections, so check yours. This single gap accounts for a large share of the surprise bills people still receive.

Other limits worth knowing

The law doesn't cover services your plan simply doesn't include.
It doesn't apply to out-of-network care at an out-of-network facility.
In some non-emergency situations, a provider can ask you to waive your protections in writing — but you are never required to sign. You can always choose an in-network provider instead.

If you think you were billed illegally

Call your health plan and ask why the claim wasn't processed as protected. If it was an emergency, ask whether it was processed as one.
Contact CMS (the Centers for Medicare & Medicaid Services) at 1-800-985-3059 or visit cms.gov/nosurprises to file a complaint.
Keep the bill, your EOB, and notes on every call.

The bottom line

Emergency care, out-of-network specialists at in-network hospitals, and air ambulances are protected — you owe only normal in-network cost-sharing.
Ground ambulances are the big exception. Know this before you need one.
You never have to sign away your protections.
Wrongly billed? Call your plan, then CMS at 1-800-985-3059 or visit cms.gov/nosurprises.

Sources: U.S. Centers for Medicare & Medicaid Services (cms.gov/nosurprises); U.S. Department of Labor No Surprises Act explainer; Health Source Magazine (Aug 2026). This is general information, not legal advice — for disputes, contact CMS or your state's insurance department.