What Is Balance Billing and When Is It Illegal

Balance billing occurs when a provider charges you the difference between their full billed rate and what your insurance actually paid. In many situations this practice is illegal under the No Surprises Act. Knowing exactly when balance billing is allowed and when it is not protects you from paying charges you do not actually owe.

This guide explains what balance billing is, when it is illegal, and the exact steps to stop it.

What balance billing means

Balance billing happens when a provider bills you for the difference between their full billed charge and the insurer's allowed, or contracted, amount. For example, a provider bills $1,200. Insurance allows and pays $800. The provider then sends you a bill for the remaining $400.

When balance billing is illegal

The federal No Surprises Act bans balance billing in several specific situations: emergency services at any hospital or facility, non-emergency care at an in-network facility when an out-of-network provider is involved, such as an anesthesiologist or assistant surgeon, and air ambulance services.

In these protected situations, you pay only your normal in-network cost-sharing, meaning your deductible, copay, or coinsurance. The provider and insurer are required to settle the remaining amount between themselves rather than passing it on to you.

When balance billing is still allowed

Balance billing remains legal when you knowingly choose an out-of-network provider at an out-of-network facility, for ground ambulance services, which the No Surprises Act does not cover, and for certain non-emergency services where you signed a valid written agreement to be balance billed.

Step-by-step actions when you receive a balance bill

Do not pay the balance-billed amount right away. Check whether the No Surprises Act applies by reviewing the date of service, whether the care was an emergency, and whether the facility itself was in-network. Send a written dispute letter to the provider stating that the No Surprises Act applies, and include a copy of your EOB or Good Faith Estimate as supporting documentation. Send a copy of that dispute to your insurer as well, and ask them to reprocess the claim and confirm the protected status directly.

If the provider continues to bill you

Use the Patient-Provider Dispute Resolution process if the bill exceeds your Good Faith Estimate by $400 or more, or file a complaint with the federal No Surprises Help Desk if the provider continues balance billing despite the protections applying.

Next steps with Bill Advantage

Stop guessing whether a bill is protected or how to write the dispute letter. Bill Advantage's No Surprises Act Disputer (Starter tier and above) reads the bill you upload or describe, identifies protected charges, and generates a ready-to-send dispute letter. Pair it with the Insurance Statement Decoder for full EOB analysis and the Denial Letter Translator if any denial codes appear on the bill. You can also review balance billing rules on the Denial Code Reference pages at billadvantage.com/denial-codes.

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Bill Advantage is a document literacy tool. Nothing in this article constitutes legal or medical advice.