By the VerifyDoc team
Going to an in-network hospital doesn't guarantee every provider who treats you is in-network — but federal law now limits how much you can be charged when that happens.
This post explains exactly how an in-network hospital can still produce an out-of-network bill, which providers are permanently protected under the No Surprises Act, when a waiver can legally strip away your protections, and the concrete steps to take when a charge looks wrong.
Why Your In-Network Hospital Can Have Out-of-Network Providers
A hospital contracts with your insurer — but the doctors who practice inside that hospital often have separate contracts. When you get services from an in-network hospital or ambulatory surgical center, certain providers there may be out-of-network, and the most those providers may bill you is your plan's in-network cost-sharing amount. This gap — a contract between the building and your insurer but not between a specific doctor and your insurer — is the root cause of the vast majority of surprise bills patients receive after scheduled procedures.
Surprise billing occurs when you have health coverage and unknowingly or unavoidably receive care from an out-of-network provider or at an out-of-network healthcare facility and are billed directly for that care when your health plan does not cover the entire cost of care. Before federal protections took effect, this often led to balance bills for hundreds or thousands of dollars. Various studies indicated that about 20% of emergency room visits resulted in surprise medical bills from out-of-network providers, and up to 16% of in-network hospitalizations resulted in surprise balance bills from out-of-network providers who participated in the patient's care.
What Federal Law Actually Says: 45 CFR § 149.120 and § 149.420
The No Surprises Act protects people covered under group and individual health plans from receiving surprise medical bills when they receive most emergency services, non-emergency services from out-of-network providers at in-network facilities, and services from out-of-network air ambulance service providers. The patient-facing rule governing non-emergency services at in-network facilities is codified at 45 CFR § 149.120 (plan obligations) and 45 CFR § 149.420 (provider obligations).
A nonparticipating provider who provides items or services (other than emergency services) at a participating health care facility must not bill, and must not hold liable, a participant, beneficiary, or enrollee for a payment amount that exceeds the cost-sharing requirement for such item or service, unless the provider satisfies the notice and consent criteria. Crucially, any cost-sharing payments made by the patient must count toward in-network deductibles and in-network out-of-pocket maximums, in the same manner as if the payments were made with respect to items and services furnished by a participating provider.
The No Surprises Act supplements state surprise billing laws; it does not supplant them. It creates a "floor" for consumer protections against surprise bills from out-of-network providers and related higher cost-sharing responsibility for patients. Some states provide stronger protections than the federal baseline, so check your state insurance department for additional rules that may apply.
The Comparison: Which Provider Types Are Always Protected vs. Sometimes Exposed
The most important thing to know is that the law draws a sharp line between ancillary services (always protected — no waiver allowed) and non-ancillary, non-emergency services (protected by default, but waivable with proper notice). The table below shows the practical difference for common in-hospital providers.
| Provider Type | Category Under 45 CFR § 149.420 | Can You Be Balance-Billed? | Can You Sign Away Protection? |
|---|---|---|---|
| Anesthesiologist | Ancillary (always protected) | No — in-network cost-sharing only | No — consent waiver prohibited |
| Radiologist / Pathologist | Ancillary (always protected) | No — in-network cost-sharing only | No — consent waiver prohibited |
| Neonatologist / Intensivist / Hospitalist | Ancillary (always protected) | No — in-network cost-sharing only | No — consent waiver prohibited |
| Assistant Surgeon | Ancillary (always protected) | No — in-network cost-sharing only | No — consent waiver prohibited |
| Lab / Diagnostic Services | Ancillary (always protected) | No — in-network cost-sharing only | No — consent waiver prohibited |
| Out-of-network surgeon (scheduled, elective) | Non-ancillary, non-emergency | Only if proper notice & consent obtained | Yes — with 72-hour written notice + GFE |
| No in-network provider available for that service at that facility | Ancillary (always protected) | No — in-network cost-sharing only | No — consent waiver prohibited |
| ER physician at in-network emergency department | Emergency services (45 CFR § 149.110) | No — in-network cost-sharing only | No — cannot waive pre-stabilization |
In non-emergency situations, notice and consent is not permitted for ancillary services, which are defined as items and services related to emergency medicine, anesthesiology, pathology, radiology, and neonatology — whether provided by a physician or non-physician practitioner — provided by assistant surgeons, hospitalists, and intensivists; diagnostic services including radiology and laboratory services; and services provided by an out-of-network provider if there is no in-network provider available.
When a Waiver Is Legal — and What It Must Include
For non-ancillary, non-emergency scheduled services, an out-of-network provider can legally ask you to waive your balance-billing protections. But the rules for that waiver are strict. If the provider did not provide you the consent form within the minimum 72 hours before the services, the provider cannot balance-bill you for the services provided. This timing requirement is codified at 45 CFR § 149.420.
Under the notice-and-consent process, an out-of-network provider generally must provide, at least 72 hours before the date of service, a written notice to the patient that includes the provider's out-of-network status, a good-faith estimate of the amount the provider may charge the patient, and a list of in-network providers at the facility that could provide the service. Providers must use the standardized government forms — they cannot substitute their own paperwork. If you sign the form, be aware that you may owe the full costs billed for the items and services you receive, and your health plan might not count any of the amount you pay towards your deductible and out-of-pocket limit.
There are also situations where a waiver is never valid. You can never be asked to waive your surprise billing protections for services provided by an out-of-network provider if there is no in-network provider who can provide the service at the facility. Likewise, providers cannot seek consent to waive NSA rights from a patient who is impaired or otherwise incapable of making an informed decision.
Illustrative Example: How This Plays Out on an Actual Bill
(The following is an illustrative example for educational purposes. Names and numbers are not drawn from any real patient's bill.)
Imagine you schedule knee surgery at Memorial Hospital, which is in-network with your plan. You pay your in-network deductible and copay. Three weeks later, you get two additional bills: one from Anesthesia Associates LLC for $1,400 and one from the assistant surgeon for $900. Both providers are out-of-network.
Under the No Surprises Act, both charges are ancillary services under 45 CFR § 149.420. Neither provider could legally present you with a consent form, and neither can balance-bill you above your in-network cost-sharing. If you paid a $200 anesthesia copay in-network, that is all you owe the anesthesiologist — regardless of what Anesthesia Associates LLC charges your plan. Any amount above your in-network cost-sharing is a billing error you can dispute. See our guide on 5 Anesthesia & Assistant Surgeon Billing Mistakes to Catch in 2026 for the specific CPT codes and dispute language to use.
Step-by-Step: What to Do When You Get an Out-of-Network Bill from an In-Network Hospital
Don't pay a surprise bill before you've verified it's legitimate. Work through these steps in order.
- Request an itemized bill and your Explanation of Benefits (EOB). The EOB shows how your insurer classified each provider. Compare the EOB to the bill line by line. If the insurer processed a charge at out-of-network rates for an ancillary provider, that's a processing error you'll dispute with the insurer, not just the provider. Our post on Balance Billing & the No Surprises Act: Know Your Rights in 2026 has a full EOB walkthrough.
- Identify whether the provider is ancillary or non-ancillary. Use the comparison table above. Anesthesiology, radiology, pathology, lab, hospitalists, assistant surgeons — all ancillary. No consent form was ever valid. If they billed you above in-network cost-sharing, you owe nothing extra.
- Check for a signed consent form. For a non-ancillary provider (e.g., an out-of-network specialist you saw at the hospital), ask whether you signed a standard government notice-and-consent form at least 72 hours in advance. If no properly executed form exists, the balance-billing protections still apply and you cannot owe more than your in-network cost-sharing.
- Dispute in writing with both the provider and your insurer. Send a letter citing 45 CFR § 149.420 by name. State the specific charge, that the provider was out-of-network at an in-network facility, and that no valid consent waiver was obtained (or that the service is ancillary and waiver was prohibited). Request the charge be reprocessed at in-network cost-sharing. Keep copies of everything.
- File a complaint with CMS if the dispute is not resolved. If you believe you've been wrongly billed, you may contact the No Surprises Help Desk at (800) 985-3059. CMS enforces the provider-side rules and can compel correction. You can also file with your state insurance department, which may have additional enforcement power under state law.
If the dispute involves an out-of-network charge your insurer and the provider can't resolve, there is a federal arbitration pathway. The No Surprises Act establishes an independent dispute resolution process for payment disputes between plans and providers, and provides new dispute resolution opportunities for uninsured and self-pay individuals when they receive a medical bill that is substantially greater than the good faith estimate they get from the provider. Read our explainer on What the Federal IDR Process Actually Means for Your Medical Bill in 2026 for the procedural details.
Plans and Coverage Types Where These Rules Don't Apply
The No Surprises Act does not cover every type of health coverage. Requirements under the No Surprises Act don't apply to beneficiaries or enrollees in Medicare, Medicaid, Indian Health Services, Veterans Affairs Health Care, or TRICARE — these programs have other protections against high medical bills. The protections also don't apply to short-term limited duration insurance (STLDI), excepted benefits, or retiree-only plans; or account-based group health plans.
If you have Medicare or Medicaid, surprise billing for the same services is still restricted — just under different regulatory authority. If you have short-term insurance, an excepted-benefit plan, or no insurance at all, your federal protections are different. Uninsured and self-pay patients are entitled to a Good Faith Estimate before scheduled services under 45 CFR § 149.610. If a provider bills you $400 or more above that estimate, you can challenge the bill. Also note that the No Surprises Act does not apply to ground ambulances — for ground ambulance billing specifically, see our post on Ambulance Billing & the No Surprises Act: What's Not Protected in 2026.
About VerifyDoc: We help patients identify errors and overcharges on medical bills. We publish guides on hospital billing, the No Surprises Act, and disputing medical charges, updated as federal and state rules change.
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Get started →Frequently asked questions
I got a bill from an anesthesiologist who treated me at my in-network hospital. Can they charge me more than my normal copay?
No. Anesthesiologists are classified as ancillary providers under 45 CFR § 149.420, which means the balance-billing prohibition applies regardless of whether you signed anything. The most the anesthesiologist can bill you is your plan's in-network cost-sharing amount — the same copay, coinsurance, or deductible portion you'd pay for any in-network provider. If you've been billed above that amount, the charge is a violation of the No Surprises Act. Dispute it in writing with both the provider and your insurer, citing 45 CFR § 149.420, and contact the No Surprises Help Desk at 1-800-985-3059 if needed.
I signed a consent form at the hospital saying my surgeon was out-of-network. Does that mean I owe the full balance bill?
It depends on whether the form was provided correctly. The consent must use the federal government's standardized notice-and-consent documents and must have been provided to you at least 72 hours before your scheduled service. If you received it less than 72 hours in advance (or on the day of surgery without a 3-hour buffer), the waiver is invalid and balance-billing protections still apply. The consent form is also never valid for ancillary services — if your out-of-network "surgeon" was actually an assistant surgeon, hospitalist, or anesthesiologist, no consent form is legally effective. If you're uncertain, request the exact date the form was delivered and compare it to your procedure date.
My insurer processed the out-of-network charge at out-of-network rates even though the No Surprises Act should apply. What do I do?
This is a plan-side processing error, and you dispute it with your insurer, not just the provider. File an internal appeal with your health plan citing 45 CFR § 149.120, which requires the plan to apply in-network cost-sharing and count any cost-sharing toward your in-network deductible and out-of-pocket maximum. Request that the claim be reprocessed. If the plan denies your appeal, you have the right to an external review. You can also file a complaint with your state insurance department or with CMS. Keep all EOBs, bills, and correspondence to document the dispute trail.
Does the No Surprises Act apply if I have Medicare, Medicaid, or a short-term health plan?
The No Surprises Act's surprise billing protections apply specifically to group and individual health insurance coverage — they don't extend to Medicare, Medicaid, TRICARE, VA Health Care, or Indian Health Services, which have their own separate protections. Short-term limited duration insurance (STLDI) and excepted-benefit plans are also excluded. If you're uninsured or self-pay, different rules apply: you're entitled to a Good Faith Estimate before scheduled services under 45 CFR § 149.610, and if your final bill exceeds that estimate by $400 or more, you can initiate a Patient-Provider Dispute Resolution process. Always verify which type of plan you hold before assuming federal surprise billing rules cover your situation.