A hospital stay handled entirely by an in-network surgeon can still generate a bill running into the thousands of dollars, because the anesthesiologist who administered sedation, the radiologist who read the imaging, or the air ambulance crew that transported the patient worked for a company the insurer never signed a contract with. For years that gap between who a patient chose and who actually treated them produced some of the largest and least predictable out-of-pocket bills in American medicine. Since January 2022, the No Surprises Act has barred most of those bills outright, moving the fight over payment away from the patient’s mailbox and onto the insurer and the provider.
Emergency Care and Facility-Based Providers Lose Their Leverage
The law’s core protection covers two situations that generated the bulk of surprise bills before 2022. The first is any emergency visit, regardless of which hospital treats the patient or whether that hospital sits inside the insurer’s network; emergency care must be billed at in-network cost-sharing rates no matter who delivers it. The second is non-emergency care received at an in-network hospital, surgery center, or other in-network facility, where a patient reasonably assumes every provider in the building is covered but discovers afterward that the anesthesiologist, pathologist, radiologist, or assistant surgeon was not.
For a defined set of facility-based specialties — anesthesiologists, radiologists, pathologists, neonatologists, emergency physicians, hospitalists, intensivists, and assistant surgeons — the ban is absolute; these providers cannot balance-bill a patient at an in-network facility even if the patient signs a consent form, because federal rules classify their services as ones a patient cannot reasonably shop for in advance. The patient owes only the in-network copayment, coinsurance, and deductible amount, and that payment counts toward the same in-network out-of-pocket maximum as care from a provider the patient chose directly.
A narrower group of non-ancillary providers can still bill out-of-network rates in limited circumstances, but only after giving the patient written notice at least 72 hours in advance and obtaining explicit consent that spells out the expected charges and confirms the patient could have chosen an in-network alternative. Facilities that skip this notice-and-consent step, or bury it in routine intake paperwork, lose the right to collect anything beyond the in-network rate, regardless of what the provider later bills the insurer.
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Air Ambulances Are Covered, Ground Ambulances Still Are Not
Air ambulance transport is one of the clearest wins in the law: a patient flown to a hospital by a helicopter or fixed-wing air ambulance outside the insurer’s network now owes only in-network cost-sharing, even though air ambulance bills before the law regularly ran into five figures. Before 2022, a single air-ambulance flight could generate a balance bill larger than the underlying hospital stay, because air ambulance operators were rarely in any insurer’s network and had no incentive to negotiate rates directly with the patient stuck holding the invoice.
Ground ambulance rides remain the largest gap in the framework. Congress left ground transport out of the statute, so a patient who calls 911 and rides to the hospital in a municipal or private ambulance can still receive a balance bill for the difference between what the ambulance company charges and what the insurer pays, even though the patient had no ability to choose which ambulance responded. CMS’s own No Surprises Act guidance acknowledges the gap, and a federal advisory committee has studied extending similar protections to ground ambulances, but no statutory fix has passed.
Disputes Move to Arbitration, Not the Patient’s Mailbox
Once a patient’s cost-sharing is locked at the in-network rate, the remaining disagreement over what the insurer actually owes the out-of-network provider or facility is resolved through a federal independent dispute resolution process, commonly called IDR. Either side can initiate a 30-day open negotiation period after the insurer’s initial payment, and if that fails, submit the dispute to a certified independent arbitrator who picks one of the two parties’ final offers — a baseball-style format meant to discourage both sides from proposing unreasonable numbers.
The patient is not a party to that arbitration and owes nothing beyond the in-network amount regardless of which side wins. CMS runs the IDR portal that providers, facilities, and health plans use to file and track these disputes, and published outcome data has shown providers prevailing in a majority of decided cases, a pattern that has drawn criticism from insurers who argue the arbitration results are pushing up premiums.
Enforcement runs through both CMS and state insurance regulators, since some protections apply only to state-regulated plans while federal rules cover self-funded employer plans that fall outside state authority. A patient who receives a bill that appears to violate the law can file a complaint with the No Surprises Help Desk, which investigates on the patient’s behalf and can require the billing provider to refund improperly collected charges rather than leaving the patient to negotiate directly with a hospital billing department.
The law extends a separate protection to patients without any insurance at all: uninsured and self-pay patients scheduling care are entitled to a written Good Faith Estimate of expected charges before the appointment, and if the final bill exceeds that estimate by $400 or more, the patient can dispute the difference through the same federal process rather than simply paying whatever appears on the invoice. That protection runs on a different track from the insured-patient balance-billing ban, but it closes a related loophole — a self-pay patient quoted one price walking in and billed a much larger one walking out.
The law does not cap what providers and insurers ultimately settle on, and it leaves the ground-ambulance gap and rising IDR caseloads as unresolved friction points that keep surfacing in billing disputes. But for the millions of patients who once discovered a five-figure anesthesiologist bill weeks after a routine in-network surgery, the practical effect has been straightforward: the fight over that bill now happens between two well-resourced institutions instead of landing on a kitchen table. CMS’s consumer advocate toolkit is where caseworkers and billing advocates turn to walk patients through a disputed charge, evidence that the law shifted the burden of proof but did not eliminate the paperwork.
This article was produced with the assistance of AI and reviewed by The Money Overview editorial team before publication.
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