Patients who end up in an emergency room at an out-of-network hospital cannot be charged more than their plan’s in-network cost-sharing amount for that visit. Federal law, codified at 42 U.S.C. Section 300gg-131 and implemented through 45 C.F.R. Section 149.410, prohibits nonparticipating providers from billing or holding patients liable beyond what they would owe at an in-network facility. Before these protections took effect, a peer-reviewed Health Affairs study found that 20% of hospital inpatient admissions originating in the emergency department and 14% of outpatient ED visits in 2014 likely led to a surprise bill.
Federal agencies enforce the in-network cap on emergency cost-sharing
The No Surprises Act, published as an interim final rule in 86 Fed. Reg. 36872 on July 13, 2021, created a nationwide floor of protection for emergency-room patients. Three federal agencies, the Department of Health and Human Services, the Department of Labor, and the Department of the Treasury, jointly administer the rule. The CMS fact sheet states plainly that out-of-network emergency services cannot lead to higher cost-sharing and that balance billing is prohibited. The Department of Labor’s Employee Benefits Security Administration echoes this, confirming that a plan cannot require more cost-sharing for out-of-network emergency services than for equivalent in-network services.
The practical effect is straightforward. If a patient’s plan sets a $250 copay and 20% coinsurance for an in-network emergency visit, those are the maximum amounts the patient owes, even if the ambulance delivers them to a hospital outside their plan’s network. The provider and the insurer must resolve any remaining payment dispute between themselves, through negotiation or through the federal independent dispute resolution process. The patient is removed from the middle of that fight.
Federal agencies have also emphasized that these protections apply regardless of the type of emergency facility, as long as it meets the statutory definition of an emergency department or qualifies as an independent freestanding emergency department under applicable law. Plans must treat covered emergency care as if it were in network for cost-sharing purposes, even when no contractual relationship exists between the insurer and the hospital or physician group.
Pre-law surprise billing rates and the scale of the problem
The size of the problem these protections address is well documented. A Health Affairs study using 2014 data found that one in five inpatient emergency admissions likely produced a surprise bill, along with 14% of outpatient emergency visits. Those figures reflected a system where patients had no control over which physicians or facilities treated them during emergencies but could still receive bills for thousands of dollars above their expected cost-sharing. No publicly available federal dataset has yet updated those prevalence figures with post-implementation data from 2022 onward, which means the actual reduction in surprise billing remains unquantified at the national level.
State-level enforcement has added another layer. New York’s Department of Financial Services, in Circular Letter No. 10 (2021), directed health insurers to apply the federal standards to fully insured plans and clarified that state surprise-billing protections continue to operate alongside the federal floor where they are stronger. Other states have issued similar guidance, reinforcing that insurers cannot sidestep the in-network cost-sharing cap by reclassifying emergency services or by narrowing their provider networks in ways that would expose patients to higher out-of-pocket costs.
These combined federal and state efforts respond to longstanding patterns in emergency medicine. Patients experiencing chest pain, trauma, or other acute conditions rarely have the opportunity to verify network status before consenting to treatment. Even when the hospital itself is in network, individual clinicians-such as emergency physicians, anesthesiologists, or radiologists-may not be. Prior to the No Surprises Act, that mismatch created fertile ground for balance bills, especially from staffing companies that remained out of network and billed patients directly for the difference between their charges and the insurer’s allowed amount.
What patients can do if they receive an improper bill
Despite the legal protections, some patients still report receiving bills that appear to violate the in-network cost-sharing cap. Federal agencies advise consumers to start by comparing the bill to their plan documents and explanation of benefits to see whether the provider has incorrectly labeled emergency care as non-emergency or out of scope. If the bill exceeds in-network cost-sharing for covered emergency services, patients can dispute it with both the provider and the insurer, citing the No Surprises Act and the underlying statutory provisions.
The Centers for Medicare & Medicaid Services operate a national help line and complaint process for potential violations. Patients can learn about their protections and how to file a complaint through CMS’s online patient rights resources. Complaints can trigger investigations and, where appropriate, enforcement actions against plans or providers that fail to honor the in-network cap.
Ultimately, the No Surprises Act shifts the financial risk of out-of-network emergency care away from patients and onto insurers and providers, who are better positioned to negotiate prices and absorb uncertainty. While data on post-implementation outcomes are still emerging, the legal framework is clear: for covered emergency services, patients should not face higher cost-sharing simply because they were treated at an out-of-network facility or by an out-of-network clinician during a crisis.
