What Is Balance Billing and Is It Legal?

You paid your insurance premium, met your deductible, and thought you were covered — then a bill arrived from a provider you never chose, demanding hundreds or thousands of dollars more. That unexpected charge has a name: balance billing. Understanding exactly what it is, when it's legal, and what rights you have is the first step toward fighting back.

What is balance billing and how does it work?

Balance billing happens when a healthcare provider charges you the difference between their billed rate and the amount your insurance company paid. Here's the mechanics: your insurer negotiates contracted rates with in-network providers. When you see an out-of-network provider — sometimes without realizing it — that provider hasn't agreed to those rates. They bill your insurer, your insurer pays a portion, and then the provider bills you for the remaining balance.

For example, an anesthesiologist bills $8,000 for a procedure. Your insurer pays $2,500, which it considers the "allowed amount." The anesthesiologist — who was never in your network — then sends you a bill for the remaining $5,500. That $5,500 charge is the balance bill. It does not count toward your in-network deductible or out-of-pocket maximum in most cases, which is what makes it so financially damaging.

Balance billing most commonly occurs in these scenarios:

• Emergency care at an out-of-network facility or from an out-of-network provider at an in-network hospital
• Anesthesiologists, radiologists, or pathologists assigned to your case without your consent
• Air ambulance transport
• Scheduled procedures where you chose the in-network surgeon but support staff were out-of-network

Is balance billing legal under federal law?

The short answer is: it depends on your situation, but federal law has significantly restricted it since January 1, 2022. The No Surprises Act (part of the Consolidated Appropriations Act of 2021) is the landmark federal law that prohibits surprise balance billing in many — though not all — circumstances.

Under the No Surprises Act, balance billing is illegal in these specific situations:

• Emergency services at any facility, regardless of whether the hospital or provider is in-network
• Non-emergency care at an in-network facility when you did not have a meaningful choice of provider (e.g., an assigned anesthesiologist or radiologist)
• Air ambulance services from out-of-network providers

In these protected situations, your cost-sharing — your copay, coinsurance, or deductible — must be calculated as if the care were in-network. The provider and your insurer are required to resolve any payment dispute between themselves through an Independent Dispute Resolution (IDR) process, not by passing the bill to you.

There is one major exception: a provider can balance bill you for non-emergency, scheduled care if they give you written notice at least 72 hours in advance, you are told the provider is out-of-network, you are given an estimate of costs, and you sign a written consent form. This is called voluntary waiver of protections. If you signed such a form without understanding what it meant, that is worth investigating — coercion or inadequate disclosure can make the waiver invalid.

Does your state have additional balance billing protections?

State-level protections vary widely and can be stronger than the federal baseline. As of 2024, more than 30 states have their own surprise billing laws. However, these state laws only apply to state-regulated insurance plans — typically plans purchased on the individual market or through small employers. If you have a self-funded employer plan (common at large companies), it is regulated by federal ERISA law, not state law, which means state protections generally do not apply to you.

States with particularly strong protections include:

• New York — has had a comprehensive surprise billing law since 2015, with an independent dispute resolution process
• California — protects patients from balance bills in both emergency and non-emergency situations under the Knox-Keene Act
• Texas — enacted the Texas Health Care Information Collection Act with dispute resolution protections
• Illinois — the Surprise Billing Protection Act covers both emergency and certain non-emergency services

To find out which laws apply to your plan, look at your Summary Plan Description (SPD) or call the member services number on your insurance card and ask directly: "Is my plan self-funded or fully insured?" The answer determines whether state surprise billing laws cover you.

How do you know if your balance bill violates the No Surprises Act?

Not every unexpected medical bill is an illegal balance bill. Walk through this checklist to assess your situation:

1. Was it emergency care? If yes, the No Surprises Act almost certainly protects you regardless of network status.
2. Was the facility in-network? If you went to an in-network hospital or surgery center, any bill from an out-of-network provider who was automatically assigned to your care is likely prohibited.
3. Did you sign a waiver? Check your intake paperwork. If you signed a waiver, check whether it was properly disclosed and whether you had a genuine alternative.
4. Is the billed amount more than your in-network cost-sharing? If the provider is billing you more than what you'd owe in-network, that's the hallmark of a balance bill.
5. What type of insurance do you have? Medicare and Medicaid have separate (and often stronger) protections. Uninsured or self-pay patients have different rights under the No Surprises Act's good faith estimate requirements.

If your bill appears to violate the No Surprises Act, you have the right to file a complaint with the Centers for Medicare & Medicaid Services (CMS) at No Surprises Help Desk: 1-800-985-3059 or online at cms.gov/nosurprises. You can also file complaints with your state insurance commissioner simultaneously.

What steps should you take to dispute an illegal balance bill?

Disputing a balance bill requires documentation and a clear paper trail. Follow these steps in order:

1. Request an itemized bill. Call the provider's billing department and request a line-by-line itemized statement. This is your legal right. Review every charge and CPT code for errors, duplicate charges, or services you don't recognize.
2. Request your Explanation of Benefits (EOB). Contact your insurer for the EOB related to this claim. Compare what the provider billed, what your insurer paid, and what they claim you owe. Look for how the claim was classified — was it processed as in-network or out-of-network?
3. Send a written dispute to the provider. Write a formal letter citing the No Surprises Act (or relevant state law) and stating that the balance bill appears to violate federal protections. Keep your tone professional and request written confirmation that the bill will be corrected. Send via certified mail.
4. File a complaint with CMS. If the provider refuses to resolve the bill, file a formal complaint at cms.gov/nosurprises. CMS can investigate and penalize providers up to $10,000 per violation.
5. Contact your state insurance commissioner. Even if state law doesn't directly apply, commissioners can apply pressure and direct you to additional resources.
6. Do not pay the disputed bill while the dispute is active. Paying may be interpreted as acceptance of the charges. Ask the provider in writing to pause collection activity during the dispute process.