Health Insurance Balance Billing: What It Is & When It’s Still Legal

What is balance billing?

Balance billing is the practice of a healthcare provider billing a patient for the difference between what the provider charged and what the patient's insurance company agreed to pay, separate from any normal copay, deductible, or coinsurance the patient already owes. This typically happens when a patient receives care from an out-of-network provider, since out-of-network providers haven't agreed to the insurer's negotiated rate and can bill the patient directly for the remaining "balance."

For example, if an out-of-network provider charges $1,000 for a service, and the insurer determines that only $600 is a reasonable "allowed amount" and pays accordingly, a balance bill would ask the patient to cover the remaining $400 difference, on top of whatever cost-sharing the patient's plan already requires. Before 2022, this was a common and often unpredictable source of large, unexpected medical bills, particularly for emergency care where patients had no real ability to choose an in-network provider in that moment.

The No Surprises Act: what changed in 2022

The federal No Surprises Act took effect January 1, 2022, and significantly changed the rules around balance billing for most privately insured patients. Under the law, balance billing is now banned in three main categories:

• Emergency care: if you receive emergency services, you cannot be balance billed, regardless of whether the hospital or treating providers are in-network with your plan.
• Out-of-network providers at an in-network facility: if you receive non-emergency care at an in-network hospital or facility, but a specific provider involved in your care, such as an anesthesiologist, radiologist, pathologist, or assisting surgeon, turns out to be out-of-network, you generally cannot be balance billed for their services.
• Air ambulance transport: out-of-network air ambulance providers are banned from balance billing patients, a change from a situation where air ambulance bills routinely exceeded $30,000 or more before the law took effect.

In each of these protected situations, you're only responsible for your normal in-network cost-sharing, your usual copay, deductible, or coinsurance, as if the provider had actually been in-network, rather than the full difference an out-of-network provider might otherwise charge.

The big gap: ground ambulance transport

Despite the significant protections above, Congress explicitly excluded ground ambulance transportation from the federal No Surprises Act. This means that as of 2026, an out-of-network ground ambulance provider can still legally balance bill a patient for the full difference between its charge and what the patient's insurer pays, unless the patient's specific state has its own protection in place.

If you've received a ground ambulance bill with a balance billing charge, checking your specific state's insurance department website, or calling to ask directly, is the most reliable way to find out whether your state offers additional protection the federal law doesn't.

It's also worth knowing that some states pair their ground ambulance balance billing ban with a minimum reimbursement rate the insurer must pay for the transport, which helps keep the ambulance provider from being left under-compensated once direct patient billing is off the table. The specific structure varies meaningfully from one state to the next, so a protection in one neighboring state doesn't necessarily tell you anything about your own.

Other situations where balance billing can still be legal

Beyond ground ambulance, a few other situations generally fall outside the federal ban:

• Elective out-of-network care you specifically choose: if you knowingly and voluntarily choose an out-of-network provider for a non-emergency service, rather than having one assigned to you at an in-network facility, balance billing protections generally don't apply the same way.
• The "notice and consent" exception: in certain limited, non-emergency, non-ancillary situations, a provider can ask you to waive your balance billing protections in writing, provided they give you proper notice, generally at least 72 hours before a scheduled appointment, or 3 hours before a same-day appointment. This waiver option is never allowed for emergency services or for ancillary services like anesthesiology, pathology, radiology, or neonatology, regardless of timing.
• Being uninsured: the No Surprises Act's balance billing protections are built around your health plan's cost-sharing rules, so if you don't have insurance at all, the law's specific protections don't apply to you in the same way, though a separate "good faith estimate" requirement does apply for uninsured and self-pay patients.
• Underpayment disputes between your insurer and the provider: if your insurer and an out-of-network provider disagree about the correct payment amount, that dispute is generally supposed to be resolved between them directly, through a federal independent dispute resolution (IDR) process, rather than by billing you the difference while the dispute is ongoing.

In practice, this independent dispute resolution process means that even when an insurer and an out-of-network provider can't initially agree on a fair payment amount, the disagreement is meant to stay between the two of them, with a neutral arbitrator helping settle it, rather than becoming your problem to resolve directly out of pocket.

What to do if you receive a balance bill

If you receive a bill that you believe violates your protections under the No Surprises Act, there are concrete steps worth taking before simply paying it:

• Review your Explanation of Benefits (EOB) from your insurer first, to confirm exactly what your plan says you owe and compare it against the bill you received.
• Contact the provider's billing department directly to ask specifically whether the service falls under one of the federal law's protected categories, and point out the discrepancy if it does.
• If you believe a protected service was improperly balance billed, you can file a complaint directly with the federal No Surprises Help Desk, which investigates potential violations of the law.
• Keep careful records of every bill, EOB, and communication related to the charge, since this documentation is often essential if a dispute needs to be escalated.
• If the bill is for a ground ambulance service, check your specific state's insurance department website for any additional protections that may apply beyond the federal law.

A quick checklist for understanding your protections

• Confirm whether your situation falls into one of the three federally protected categories: emergency care, an out-of-network provider at an in-network facility, or air ambulance transport.
• If you received ground ambulance transport, check your specific state's additional protections, since federal law doesn't cover this category at all.
• Before any non-emergency procedure, ask directly whether every provider involved, including anesthesiologists and other specialists, is in-network, not just the facility itself.
• Never sign a waiver of your balance billing protections without understanding exactly what you're giving up and whether the specific service actually qualifies for that waiver option.
• If you receive a bill you believe is improper, file a complaint with the No Surprises Help Desk rather than simply paying it outright.

For the authoritative, non-commercial sources on this topic, the Centers for Medicare & Medicaid Services (CMS) publishes official guidance on the No Surprises Act directly, and the Consumer Financial Protection Bureau (CFPB) publishes consumer guidance on medical billing and your specific rights.

Frequently asked questions about balance billing

Have a question that isn't answered below? Our full health insurance FAQ page covers more, and our blog has deeper guides on specific coverage topics.