Healthcare Data GlossaryProvider
Ambulatory Surgical Center: Definition and Healthcare Context
Full name: Ambulatory Surgical Center (ASC)
An Ambulatory Surgical Center (ASC) is a Medicare-certified health care facility that provides surgical services to patients who do not require hospitalization. CMS certifies ASCs under Conditions for Coverage and reimburses them under the ASC Payment System. CMS publishes quality and performance data for over 5,600 Medicare-certified ASCs through the Care Compare ASC dataset. Common ASC procedures include cataract surgery, colonoscopies, and orthopedic procedures. ASCs collectively perform more than 23 million procedures annually in the United States.
Last updated: 2026-06-17Reviewed by: Dr. Jennifer Montecillo, MD — Gullas College of Medicine, 2019. Non-practicing medical reviewer.
How it’s used
- CMS Care Compare — ASC Quality Measures: ASC quality measures including complication and unplanned hospital transfer rates are published through Care Compare, drawn from the CMS Care Compare ASC dataset.
- CMS Provider of Services (POS) file: ASCs are certified facilities keyed by CCN in the POS file, the identity backbone Fonteum uses to join ASC quality to enrollment data.
- CMS ASC Payment System: Medicare reimburses ASCs under a distinct payment system, and the roughly 5,600 certified ASCs are the population Fonteum's ASC dataset covers.
Frequently asked questions
- What is an ambulatory surgical center?
- An ASC (Ambulatory Surgical Center) is a Medicare-certified facility that performs same-day surgical procedures on patients who do not require overnight hospitalization.
- How does CMS pay ASCs?
- CMS pays Medicare-certified ASCs under the ASC Payment System, a prospective payment based on ambulatory payment classification (APC) groupings.
- How many ASCs participate in Medicare?
- Over 5,600 ASCs are certified to participate in Medicare as of 2024.