How to Fight a Balance Bill: Step-by-Step

Quick Answer: Balance billing for emergency care and most out-of-network services at in-network facilities became illegal under the No Surprises Act in 2022. If you received such a bill, file a complaint with CMS at nsa-idr.cms.gov and send a written dispute to the provider citing the specific NSA violation. Do not pay the balance before verifying whether the law protects you.

What Balance Billing Is

Balance billing happens when an out-of-network provider bills you for the difference between what your insurer paid and the provider's full charge. Example: your insurer pays $800 toward a $2,000 anesthesiology bill. The anesthesiologist bills you the remaining $1,200. That gap is a "balance bill."

For decades this practice was common and largely legal. The No Surprises Act (NSA), which took effect January 1, 2022, changed that for a significant category of situations.

When Balance Billing Is Illegal (The NSA)

The No Surprises Act prohibits balance billing in these situations:

  • Emergency services at any facility — regardless of whether the ER is in-network, you cannot be balance billed for emergency care.
  • Out-of-network providers at in-network facilities — if you chose an in-network hospital but were seen by an out-of-network surgeon, radiologist, anesthesiologist, or other provider, they cannot balance bill you.
  • Air ambulance services — air ambulance providers are covered by the NSA and cannot balance bill beyond in-network cost-sharing.

In these cases your cost-sharing (deductible, copay, coinsurance) is calculated as if the service was in-network. The balance dispute is between the provider and your insurer — not between the provider and you.

When Balance Billing Is Legal

The NSA does not cover every situation. Balance billing is still legal when:

  • You chose an out-of-network provider for non-emergency care and signed a valid notice-and-consent form acknowledging the potential costs beforehand.
  • The service was with a ground ambulance — ground ambulances are explicitly excluded from the NSA (more on this in our ambulance guide).
  • You received care at an out-of-network facility for non-emergency, scheduled care.

Even when balance billing is technically legal, the amount may still be negotiable. A provider's "full charge" is an arbitrary number — always ask for the Medicare rate as a negotiating anchor.

Step 1: Verify the Bill Is an NSA Violation

Before filing anything, confirm the situation qualifies:

  • Was this an emergency? Check your EOB — emergency claims are coded differently than elective visits.
  • Was the facility in-network? Check your insurer's provider directory for the date of service.
  • Did you sign a notice-and-consent form? If yes, review it carefully — consent cannot be obtained mid-procedure or under duress.
  • Is this an air ambulance? Covered. Ground ambulance? Not covered.

Step 2: Send a Written Dispute to the Provider

Put the provider on notice in writing before you do anything else. Your dispute letter should:

  • State the date of service, facility name, and the amount being disputed.
  • Cite the No Surprises Act (Public Law 116-260) and specifically that the service falls within its protections.
  • State that you will not pay more than your in-network cost-sharing amount.
  • Request written confirmation that the balance will be resolved with your insurer rather than billed to you.

Send by certified mail and keep a copy. The provider has a legal obligation to respond and cannot send the balance to collections while a dispute is active.

Step 3: File a Federal Complaint With CMS

If the provider does not withdraw the balance bill or your insurer is not processing the claim correctly, file a complaint with the Centers for Medicare and Medicaid Services:

  • Go to nsa-idr.cms.gov or call 1-800-985-3059.
  • Select "Consumer Complaint" and provide your EOB, the balance bill, and your dispute letter.
  • CMS will investigate and contact the provider on your behalf.
  • Providers found in violation face civil monetary penalties of up to $10,000 per violation.

Step 4: File a State Insurance Complaint

Many states have enacted their own surprise billing protections that go beyond the federal law, covering situations the NSA does not. File a parallel complaint with your state insurance commissioner's office. State complaints carry additional leverage, particularly for insurer disputes about cost-sharing calculations.

Find your state insurance department at naic.org/state_web_map.htm.

The Independent Dispute Resolution (IDR) Process

The IDR process is for providers and insurers to resolve payment disputes — not for patients. But understanding the timeline helps you know what's happening with your bill:

  • Days 1–30: The provider and insurer negotiate a payment amount directly.
  • Days 31–34: If no agreement, either party initiates IDR through a certified IDR entity. The 4-business-day window to initiate is strict.
  • Days 35–65: The IDR entity reviews both offers and selects one (baseball-style arbitration). The losing party pays the IDR fee (typically $350–$700).
  • After decision: Your insurer pays the IDR-determined amount. Your cost-sharing does not change — you still owe only in-network cost-sharing.

If you receive a bill during this process, respond in writing that an IDR proceeding is underway and payment collection must pause.

Template Dispute Language

Use this language in your written dispute to the provider:

"I am writing to dispute the balance bill dated [DATE] in the amount of $[AMOUNT]. This service was provided at [FACILITY NAME], an in-network facility, on [DATE OF SERVICE]. Under the No Surprises Act (Pub. L. 116-260), I am entitled to pay only my in-network cost-sharing for this service. I am not responsible for any balance above that amount. Please confirm in writing that this balance will be resolved through the payer-provider dispute process and will not be sent to collections or reported to credit bureaus. I have also filed a complaint with CMS."

What to Do If the Bill Goes to Collections Anyway

This is illegal under the NSA if a dispute is active. If it happens:

  • Send the collection agency a copy of your open CMS complaint number and your dispute letter.
  • File an additional complaint with the CFPB at consumerfinance.gov/complaint noting the NSA violation.
  • Contact your state attorney general's consumer protection office.
  • Consult a patient advocate or consumer attorney — NSA violations are enforceable and providers face significant penalties.