Medicare & Ambulatory Surgery Center

Medicare covers approved surgical procedures performed in an ambulatory surgery center. But you will still be responsible for some out-of-pocket costs including any facility fees that Medicare does not cover.

Does Medicare Cover Ambulatory Surgery Centers?

Medicare Part B medical insurance covers service fees associated with approved surgical procedures at an ambulatory surgery center (ASC). To be covered, you should be expected to be released from the center within 24 hours of your surgery.

Examples of Ambulatory Surgery Center Services Covered by Medicare
  • Nursing services
  • Recovery care
  • Anesthetics
  • Drugs supplied while in the ASC
  • Supplies necessary for your procedure
  • Fees for doctors and anesthesiologists

Medicare covers all procedures that do not pose a significant risk if they are performed in an ambulatory surgery center so long as they don’t require an overnight stay.

As of 2018, there were roughly 3,600 different types of procedures performed at ambulatory surgery centers covered by Medicare, according to the Medicare Payment Advisory Commission (MedPAC).

Your Share of Costs for Ambulatory Surgery Center Services Under Medicare

If you have Medicare Part B and have a procedure at an ambulatory surgery center, Medicare will cover up to 80 percent of the cost.

You are responsible for the Medicare Part B deductible and for 20 percent of the Medicare-approved cost of your procedure and 20 percent of the doctor fees.

You also have to pay all facility fees for any procedure that Medicare does not cover in an ambulatory surgery center.

How Much Does It Cost?
If you are considering a procedure at an ambulatory surgery center, you can look up a ballpark estimate for its cost, and your share, at Medicare’s Procedure Price Lookup tool.
Source: U.S. Centers for Medicare & Medicaid Services

Medicare covers all costs for certain preventive services performed in an ASC, so you’ll have no out-of-pocket costs for those services.

Differences Between an Ambulatory Surgical Center and a Hospital

Ambulatory surgery centers are freestanding outpatient facilities. They may be run by hospitals but perform outpatient services — meaning procedures that can be done without requiring a patient be admitted to a hospital.

Hospitals are equipped to handle inpatient services — meaning you are admitted to a hospital and may stay there overnight or longer. Hospitals also typically provide wide ranging services beyond those needed for ASC services. These can include MRI departments, intensive care units and other advanced care facilities and services.

Ambulatory Surgery Centers vs. Hospitals
Ambulatory Surgery CentersHospitals
Focused on specific care for a specific procedureProvides full services from surgery to intensive care to in house testing and imaging
Patients tend to be healthier, treated for a specific procedurePatients may have a wide range of health conditions and needed treatments
Stays limited to 24 hour or lessStays may last 24 hours or longer
Typically lower procedure costsTypically higher procedure costs

Because ambulatory surgery centers are focused on specific procedures, they do not need the full range of services available at a hospital. This lower overhead allows an ASC to perform certain procedures at a lower cost than what the same procedure might cost in a hospital.

But it also may limit the type of procedures available at an ambulatory surgery center. At the same time, ASCs are a practical alternative for several procedures that can be safely performed without the need for a hospital’s full range of resources and in which you don’t need to stay overnight.

Most Common Medicare-Approved Procedures in Ambulatory Surgical Centers
  • Cataract removal with lens insertion
  • Upper gastrointestinal endoscopy
  • Colonoscopy
  • Nerve-related procedures

Not every patient or procedure is suited for an ambulatory surgery center. You should talk with your doctor about whether an ASC or a hospital is the best location for your procedure.

Last Modified: August 5, 2021

5 Cited Research Articles

  1. MedPAC. (2018, October). Ambulatory Surgical Center Services Payment System. Retrieved from
  2. U.S. Centers for Medicare & Medicaid Services. (n.d.). Ambulatory Surgical Centers. Retrieved from
  3. U.S. Centers for Medicare & Medicaid Services. (n.d.). Procedure Price Lookup. Retrieved from
  4. Xenon Health. (n.d.). Choosing a Hospital vs. a Surgery Center. Retrieved from
  5. Summit Orthopedics. (n.d.). What Are the Differences Between an Ambulatory Surgery Center and a Hospital? Retrieved from