Outpatient Surgery Center vs. Hospital: Cost Guide

Most of our guides help after you get a medical bill. This one helps you avoid the big bill in the first place.

If your doctor recommends an elective or semi-elective outpatient procedure (a knee scope, a hernia repair, a colonoscopy), the facility where you have it done can change your bill by thousands of dollars. A study of over two million patients found that hospitals charged 44--55% more than outpatient surgery centers for the same three procedures, with no difference in complication rates. (Source: Robinson et al., American Journal of Managed Care, 2024)

The surgeon is the same. The procedure is the same. The difference is the hospital facility fee (one of the largest hidden markups in American healthcare).

Why Your Surgery Location Affects Your Bill

Every outpatient procedure generates a hospital facility fee: a charge that covers the operating room, nursing staff, recovery area, equipment, and overhead. Both hospitals and outpatient surgery centers charge this fee. The difference is how much.

Hospital outpatient departments carry the overhead of an emergency room, intensive care units, teaching programs, and 24-hour staffing (costs that get baked into the facility fee for every procedure, including the routine ones). An outpatient surgery center is purpose-built to do outpatient procedures and nothing else. Lower overhead means a lower facility fee.

How much lower? Studies using both Medicare and commercial insurance data have found that outpatient surgery center facility fees run 40--55% below hospital outpatient departments for common procedures. (Source: Robinson et al., AJMC, 2024; McCormick et al., Orthopaedic Journal of Sports Medicine, 2025)

That is the facility fee differential. Your total savings will be lower than that headline number, because two of the bills you receive (the surgeon's fee and the anesthesia fee) are billed separately and do not change much based on where you have the procedure. More on that in a moment.

Still, the facility fee is by far the largest component of a surgical bill. When you cut it nearly in half, the savings are real.

What Is an Outpatient Surgery Center?

An outpatient surgery center (known in clinical settings as an ambulatory surgery center, or ASC) is a licensed facility where surgeries and procedures are performed on a same-day, go-home-after basis. No overnight stay. You walk in, have your procedure, recover for a few hours, and go home.

There are over 6,500 Medicare-certified ASCs operating across the United States. (Source: ASCA, citing CMS March 2025 data) They handle a wide range of procedures: orthopedic surgery (knees, shoulders, hips), cataract removal, colonoscopies, hernia repair, ENT procedures, some spine surgeries, and more.

The scope is expanding. In November 2025, CMS finalized a rule adding 560 new procedures to the ASC Covered Procedures List for calendar year 2026 (289 based on revised eligibility criteria and 271 removed from the old "inpatient only" list). (Source: LUGPA CY 2026 Rule Summary; McDermott+ CY 2026 Analysis) That inpatient-only phase-out continues through January 2028, meaning the list of procedures eligible for ASC settings will keep growing.

Not every procedure is appropriate for an outpatient surgery center, and not every patient is a candidate. Complex surgeries requiring ICU backup, overnight monitoring, or extensive inpatient recovery still belong in a hospital. The surgeon makes this determination (not you, not a billing guide). What this article does is help you ask the right question: if my procedure can be done at an outpatient surgery center, how much could I save?

How Much Can You Actually Save?

The short answer: it depends on the procedure, your insurance, and how much of your deductible you have already met. Here is what the research shows.

The Facility Fee Differential

Why Your Total Bill Is Not 40--55% Lower

That 40--55% figure is the facility fee differential. Your total out-of-pocket experience will look different because of how surgical billing actually works.

You will not receive one bill. You will receive three or four:

1. Facility fee (from the surgery center): Covers the operating room, nursing, recovery, supplies, and equipment. This is the bill that is 40--55% lower at an ASC.
2. Surgeon's professional fee (from the surgeon): Billed separately under the surgeon's own billing number. This fee is the same whether your surgeon operates at an ASC or a hospital. (Source: McCormick et al., Orthopaedic Journal of Sports Medicine, 2025)
3. Anesthesia fee (from the anesthesia provider): Almost always billed separately. Anesthesia charges are calculated by time and complexity, and are often comparable across settings.
4. Pathology or implant fees (if applicable): Tissue samples, lab work, or surgical hardware may generate additional separate bills.

When you add identical surgeon fees and comparable anesthesia to a lower facility fee, total patient out-of-pocket savings come out lower than the facility fee headline. The PMC study found that patients saved 37% on total out-of-pocket costs for sports medicine procedures (meaningful, but not the same as 40--55%). (Source: McCormick et al., Orthopaedic Journal of Sports Medicine, 2025)

The system-level savings are larger. According to ASCA (the ambulatory surgery center industry's trade association), citing analysis by KNG Health Consulting, ASCs saved Medicare $27.9 billion from 2019 to 2024. (Source: ASCA Medicare Cost Savings) A UnitedHealth Group brief, also cited by ASCA, estimated that shifting eligible procedures to ASCs could save commercially insured patients an average of $684 per procedure. (Source: ASCA Savings) Those are industry-sourced figures and should be understood as such, but even the more conservative peer-reviewed estimates show savings worth pursuing for any patient facing an elective procedure.

How to Find and Compare Outpatient Surgery Centers

Finding out whether your procedure could be done at an outpatient surgery center is straightforward. Getting a complete cost comparison takes more work, but it is the single most valuable thing you can do before scheduling.

Five steps to a real comparison

1. Ask your surgeon. "Can this procedure be done at an outpatient surgery center?" The surgeon knows which procedures are appropriate for an ASC setting based on the procedure complexity and your health status. If the answer is yes, ask which ASCs they operate at.

2. Search for certified facilities. Use Medicare's Care Compare tool or your state's health department licensing database to find Medicare-certified ASCs in your area. Medicare certification means the facility meets federal health and safety standards.

3. Get a total cost estimate from the ASC. Call the surgery center and ask for the complete picture: facility fee, who provides anesthesia and their billing contact, whether implants or devices are billed separately, and whether the facility is in-network with your insurance. Ask for a Good Faith Estimate that includes all expected charges from all providers.

4. Get a comparable estimate from the hospital. Request a Good Faith Estimate from the hospital for the same procedure. Ask specifically about the facility fee, whether anesthesia is billed separately, and any additional observation or recovery charges.

5. Compare total all-in costs. Do not compare facility fees alone (that is an apples-to-oranges mistake). Use the table below:

Getting complete quotes is harder than it sounds. Many facilities will only quote the facility fee and tell you to call the anesthesia group separately. Some will not give any estimate without first verifying your insurance. This friction is real, and it is part of why patients end up surprised. Push through it. The Good Faith Estimate is your legal right if you are uninsured or self-pay (use it).

Insurance and Payment Considerations

How much you actually save depends on whether you are paying through insurance or paying cash. The math works differently in each case.

Insured Path: The Coinsurance Math

If both the ASC and the hospital are in-network with your plan, you pay your plan's cost-sharing (deductible, coinsurance, or copay) applied to the insurer's allowed amount at each facility. The allowed amount at an in-network ASC is typically lower than at an in-network hospital.

Here is what that looks like in practice. Say you have 20% coinsurance after your deductible:

• 20% of a $3,000 ASC allowed amount = $600 out of pocket
• 20% of a $7,000 hospital allowed amount = $1,400 out of pocket

Same surgery. Same coinsurance percentage. Same surgeon. $800 difference (driven entirely by the facility fee).

High-deductible plan advantage: If you have a high-deductible health plan (HDHP) and have not yet met your deductible, you are paying dollar-for-dollar on the allowed amount. The ASC advantage is maximized in this scenario because you pay the full lower amount rather than the full higher one. HSA funds can be used at either setting.

When the savings disappear: If you have already met your annual out-of-pocket maximum, insurance pays 100% either way. The facility fee difference does not matter. Similarly, if your deductible is higher than the ASC facility fee, you may pay the full ASC charge out of pocket. It will still likely be less than the hospital charge, but it will feel like insurance is not helping.

Know your plan type. HMO and EPO plans have no out-of-network benefit. If the ASC is not in the HMO network, it is not covered (period). PPO plans offer some out-of-network coverage at higher cost-sharing. Check your plan type before you shop.

Verify everything by phone:

1. Call the number on the back of your insurance card
2. Ask: "Is [ASC name and address] an in-network facility under my plan?"
3. Ask: "Who provides anesthesia at that facility, and are they in-network?"
4. Get a reference number for the call
5. Do not rely solely on the insurer's online provider directory (directories are frequently outdated)

The anesthesia question matters. Even at an in-network ASC, the anesthesia group may be out-of-network. If so, the No Surprises Act protects you: the out-of-network anesthesiologist can only charge you your in-network cost-sharing amount. Anesthesiology is classified as an ancillary service under the law, which means this protection cannot be waived — even if you are asked to sign a notice-and-consent form. You do not need to do anything to preserve this right.

Cash-Pay Path: Bundled Pricing and Your GFE Rights

If you are uninsured or choosing to self-pay, you have two tools working in your favor.

Your Good Faith Estimate right. Under the No Surprises Act, ASCs must provide a Good Faith Estimate (GFE) to any uninsured or self-pay patient before scheduled services. The GFE must include expected charges from the ASC and all co-providers (surgeon, anesthesia, pathology). If the final bill exceeds the GFE by $400 or more, you can initiate the Patient-Provider Dispute Resolution process through HHS. (Source: CMS.gov No Surprises Act)

This is the strongest federal protection available to cash-pay patients at ASCs. Use it.

Bundled pricing ASCs. Some surgery centers offer all-inclusive pricing that bundles facility, surgeon, anesthesia, supplies, and uncomplicated follow-up into a single quoted price. Surgery Center of Oklahoma pioneered this model, posting all-inclusive prices online since 2009. WellBridge Surgical in Indianapolis offers a similar transparent pricing approach across multiple specialties.

These facilities are the exception, not the norm. Most ASCs bill each component separately, just like hospitals do. If an ASC advertises "bundled" or "all-inclusive" pricing, get confirmation in writing that the price covers:

• Facility fee
• Surgeon's professional fee
• Anesthesia
• All surgical supplies and implants
• What happens financially if additional procedures are needed during surgery
• Whether follow-up visits are included
• What happens financially if complications require hospital transfer

One trade-off to know about: If you pay cash and do not file with your insurance, the payment does not count toward your in-network deductible or out-of-pocket maximum. For some patients, the cash price is low enough that this trade-off is worth it. For others (especially those close to meeting their deductible), it is not.

How to Check Safety and Quality

An understandable concern: if outpatient surgery centers cost less, are they cutting corners?

The evidence says no (for appropriately selected patients).

The AJMC study of over two million patients found that complication rates were not lower at hospitals than at outpatient surgery centers for three of the most common ambulatory procedures: colonoscopy, knee/shoulder arthroscopy, and cataract removal. For colonoscopy, complications were actually slightly higher at hospitals over a 90-day interval. For the other procedures, rates were statistically and clinically similar. (Source: Robinson et al., AJMC, 2024)

A separate 2023 study that matched patients on 169 risk factors found ASC patients had lower complication rates (though the authors themselves cautioned that unmeasured differences in patient selection could explain part of the gap). (Source: PMC Safety Study, 2023)

This does not mean ASCs are safer than hospitals. It means that for the procedures and patients appropriate for an ASC setting, the safety outcomes are comparable. Sicker patients, more complex cases, and higher-risk procedures go to hospitals for good reason (and those cases are not represented in the ASC data).

What to verify before you schedule

• Medicare certification. Check the ASC on Medicare's Care Compare. Certification means the facility meets federal health and safety standards and is inspected periodically.
• Accreditation. Look for accreditation from the AAAHC (Accreditation Association for Ambulatory Health Care), the Joint Commission, or AAAASF (American Association for Accreditation of Ambulatory Surgery Facilities).
• Emergency transfer agreement. All Medicare-certified ASCs must have a written transfer agreement with a nearby hospital or ensure all surgeons have admitting privileges at one. Ask the ASC which hospital they transfer to (and verify that hospital is in your insurance network).
• Your surgeon's volume. A surgeon who performs your procedure regularly at an ASC is a better indicator of safety than the facility name on the door.

What Outpatient Surgery Centers Cannot Do

This article is about saving money on appropriate outpatient procedures. It is not a recommendation to choose an ASC in situations where a hospital is the right setting.

ASCs are not appropriate for:

• Emergency surgery
• Procedures requiring ICU backup or overnight monitoring
• Complex surgeries with high expected blood loss or complication risk
• Patients with significant comorbidities (uncontrolled diabetes, severe cardiac or pulmonary conditions, high anesthesia risk (ASA class III or higher), or very high BMI) may be disqualified from ASC care

The surgeon determines appropriateness. This guide empowers you to ask the question ("Can this be done at an outpatient surgery center?"), not to override clinical judgment.

Complication transfer: understand the financial exposure. If a complication during or after an ASC procedure requires hospital transfer, you may receive separate bills from the ASC (for services rendered), the hospital (as a new encounter at hospital rates), the ambulance service, and additional providers at the hospital. Ground ambulance is not covered by the No Surprises Act (a known gap in the law).

This is a low-probability event for appropriately screened patients, but the financial exposure is real. Ask the ASC about its transfer agreement and which hospital it transfers to. Verify that hospital is in your insurance network.

In some markets, there is no nearby ASC. Over 6,500 Medicare-certified ASCs operate nationwide, but they are concentrated in urban and suburban areas. (Source: ASCA, citing CMS March 2025 data) In rural areas, the nearest ASC may be out of network, far away, or nonexistent. Some states also have certificate-of-need laws that limit ASC development, further restricting availability.

Some hospitals compete on price. Not every hospital charges dramatically more than an ASC. Some hospital systems have created dedicated outpatient surgery departments with competitive pricing in response to ASC competition. The comparison process in this guide will surface those cases (that is why you get quotes from both).

Related Guides

For hospital bills you have already received, see our guides on how to negotiate a hospital bill and understanding hospital chargemaster prices. For a broader overview of cost-cutting strategies, see how to lower your medical bills.