Quick Summary: Key Protections at a Glance
| Situation | What the Law Supports |
| Emergency care | Protection from balance billing; no prior authorization required |
| Non-emergency care at in-network facilities | Certain out-of-network clinicians cannot balance bill |
| Air ambulance services | Balance billing protections generally apply |
| Ground ambulance services | Not always covered under federal rules |
| Uninsured or self-pay patients | Right to a good faith estimate before scheduled care |
| Bill ≥ $400 over estimate | Access to a federal dispute process |
Introduction
A surprise medical bill, often referred to as balance billing, is an unexpected charge that can occur when a patient receives care from an out-of-network provider without realizing it in advance. The federal No Surprises Act establishes protections that limit when these bills can occur and how much patients can be charged. This article explains what surprise medical bills are, when protections apply, what rights uninsured or self-pay patients have, and what steps are supported by high-quality evidence if a bill appears incorrect.
What Is a Surprise Medical Bill?
A surprise medical bill generally occurs when:
- A patient unknowingly receives care from an out-of-network provider, or
- A patient receives care in an emergency or at an in-network facility but is treated by one or more out-of-network clinicians involved in that care.
Balance billing is the practice of charging a patient the difference between what an out-of-network provider charges and what a health plan pays. Multiple providers may bill separately for the same visit, which can result in more than one bill.
What the No Surprises Act Does
The No Surprises Act is a federal law that limits balance billing in specific situations and caps what insured patients can be charged. Verified protections include:
- Limits on balance billing in defined emergency and non-emergency situations
- Restrictions so that insured patients generally pay no more than in-network cost-sharing amounts
- Requirements for providers and facilities to give notices explaining billing protections
- Dispute resolution processes for uninsured or self-pay patients in certain circumstances
Health care providers and facilities must also give you an easy-to-understand notice that explains how receiving care from an out-of-network provider could result in higher costs. This notice must outline your options to avoid surprise or balance bills and clarify that you are not required to sign it or to receive care from an out-of-network provider.
These protections apply to many group and individual health plans.
Updated Provider Directories and Cost-Sharing Limits
The law also lays out clear responsibilities for health plans when it comes to provider directories and your out-of-pocket costs. Health plans must regularly update their provider directories to ensure that the listed information—such as whether a clinician or facility is in-network—is accurate and up to date.
If you rely on information from your plan’s directory and inadvertently receive care from an out-of-network provider because of an error, your plan is required to limit your copays, coinsurance, or deductibles to what you would have paid if the provider had been in-network. This helps protect you from unexpected higher charges due to outdated or incorrect directory listings.
When You Are Protected From Balance Billing
Emergency Care
If you receive emergency services:
- You are protected from balance billing even if the facility or clinicians are out of network.
- You generally cannot be charged more than the in-network cost-sharing amount.
- Emergency services must be covered without requiring prior authorization.
Non-Emergency Care at an In-Network Facility
You may also be protected when you receive non-emergency care at an in-network hospital or facility but are treated by out-of-network clinicians you did not choose. This protection applies to certain ancillary services, including anesthesia, radiology, and pathology. In these situations:
- Balance billing is generally not allowed.
- Your cost-sharing is limited to in-network amounts.
Air and Ground Ambulance Services
Air Ambulance Services
The law includes protections for air ambulance services:
- Patients with covered plans are generally protected from balance billing for air ambulance services.
- Ground ambulance services are treated differently and are not always covered by the same federal rules.
Ground Ambulance Services
Currently, federal law does not include balance billing protections for ground ambulance bills. This means that if you require ground ambulance transport, you may be billed for the difference between what your insurance pays and the total cost charged by the ambulance provider. For more information about ongoing efforts and recommendations to address this gap, you can visit resources such as the CMS Action Plan on ground ambulance billing.
If You Are Uninsured or Self-Pay
Patients who do not have insurance or who choose not to use insurance have the right to receive a good faith estimate before scheduled non-emergency care. A good faith estimate should include:
- Expected costs for the main service
- Costs for related services that are reasonably expected
- Information about when the care will be provided
Choosing Whether to Use Insurance or Pay Out-of-Pocket
You are not required to use your health insurance for every medical service. In fact, you may decide to pay out-of-pocket in scenarios where your insurance does not cover a service, or when paying cash is more affordable than using your insurance benefits. For example, certain clinics and urgent care facilities sometimes offer discounted self-pay rates that can be lower than your plan’s deductible or co-insurance amounts.
If you choose not to use your insurance and instead pay on your own, you still have rights under the No Surprises Act. This includes receiving a good faith estimate in writing before your scheduled care, outlining your expected costs so you can make an informed decision.
Understanding these options can help you minimize surprise expenses and choose the most cost-effective approach to your care.
When a Final Bill Is Higher Than the Estimate
If you are uninsured or self-pay and your final bill is at least $400 higher than your good faith estimate, federal guidance supports access to a dispute resolution process. This process reviews whether the higher charge is appropriate, subject to specific thresholds and timing requirements.
What to Do If You Think You Received a Surprise Bill
High-quality evidence supports the following steps:
- Review your explanation of benefits (EOB) if you are insured to understand what your plan paid and why.
- Contact your health plan for clarification if coverage was denied or paid differently than expected.
- Ask about the plan’s appeals process and submit required information as directed.
- Seek assistance from federal or state resources if you believe the bill violates surprise billing protections.
Where to Get Help or File a Complaint
If you believe a bill violates your protections, authoritative sources identify these options:
- Contact the federal No Surprises Act help desk.
- Reach out to your state insurance department or consumer assistance program.
These resources can explain your rights and outline available complaint or review processes.
Federal vs. State Law
Some states have their own surprise billing protections. In many cases:
- Federal law acts as a minimum standard.
- State laws may provide additional protections or processes, depending on the type of health plan and location.
Because rules vary, guidance from your state insurance department can help clarify which protections apply.
When to See a Doctor
The No Surprises Act addresses billing protections, not whether or when to seek medical care. High-quality evidence does not support delaying necessary emergency or medically indicated care due to billing concerns. Decisions about seeking care should be based on medical need, not billing uncertainty.
Frequently Asked Questions
What are surprise medical bills?
Surprise medical bills are unexpected charges that can occur when you receive care from an out-of-network provider without knowing it in advance.
What services are protected under the No Surprises Act?
Verified protections apply to most emergency services, certain non-emergency services at in-network facilities, and air ambulance services.
What if I don’t have insurance—can I get a cost estimate first?
Yes. Uninsured or self-pay patients have the right to receive a good faith estimate before scheduled non-emergency care.
Does the emergency room charge you upfront?
There is no high-quality evidence supporting this as a general rule.
Does the ER bill you later?
There is no high-quality evidence supporting this as a universal practice.
What are surprise medical bills?
Surprise medical bills are unexpected charges that may occur when care is received from out-of-network providers without prior awareness, particularly in emergencies or certain in-network facility settings.
APA Reference List
Centers for Medicare & Medicaid Services. (2022, January 3). No Surprises: Understand your rights against surprise medical bills. https://www.cms.gov/newsroom/fact-sheets/no-surprises-understand-your-rights-against-surprise-medical-bills
Centers for Medicare & Medicaid Services. (2024, November 5). How to read your medical bill. https://www.cms.gov/medical-bill-rights/help/guides/how-to-read-bill
Centers for Medicare & Medicaid Services. (2024, November 5). Medical bill rights. https://www.cms.gov/medical-bill-rights
Centers for Medicare & Medicaid Services. (2025, April 23). Ending surprise medical bills. https://www.cms.gov/nosurprises
Centers for Medicare & Medicaid Services. (2025, June 12). You have rights in an emergency room under EMTALA. https://www.cms.gov/priorities/your-patient-rights/emergency-room-rights
Commonwealth of Pennsylvania, Department of Insurance. (n.d.). Request a review of an unexpected medical bill – No Surprises Act. https://www.pa.gov/services/insurance/request-a-review-of-an-unexpected-medical-bill-no-surprises-act
Consumer Financial Protection Bureau. (2024, October 1). Consumer advisory: Pause and review your rights when you hear from a medical debt collector. https://www.consumerfinance.gov/about-us/newsroom/consumer-advisory-pause-and-review-your-rights-when-you-hear-from-a-medical-debt-collector/
HCA Florida Healthcare. (n.d.). Surprise billing protections. https://www.hcafloridahealthcare.com/legal/surprise-billing-protections
Mayo Clinic. (n.d.). No Surprises Act. https://www.mayoclinic.org/billing-insurance/no-surprises-act
U.S. Department of Labor, Employee Benefits Security Administration. (n.d.). Avoid surprise healthcare expenses: How the No Surprises Act can protect you. https://www.dol.gov/agencies/ebsa/about-ebsa/our-activities/resource-center/publications/avoid-surprise-healthcare-expenses
U.S. National Library of Medicine. (n.d.). Understanding your hospital bill. MedlinePlus Medical Encyclopedia. https://medlineplus.gov/ency/patientinstructions/000881.htm