An ambulatory surgery center (ASC) is a health care facility that specializes in providing surgery, pain management and certain diagnostic (e.g., colonoscopy) services in an outpatient setting.
Overall, the services provided can be generally called procedures. In simple terms, ASC-qualified procedures can be considered procedures that are more intensive than those done in the average doctor's office but not so intensive as to require a hospital stay.
Ambulatory surgery centers do not provide emergency services. 'Procedures' performed in surgery centers are broad in scope. In the 1980s and 1990s, many procedures that used to be performed exclusively in hospitals began taking place in ambulatory surgery centers as well. Many knee, shoulder, eye, and other surgeries are currently performed in ambulatory surgery centers. Some heart procedures are even taking place in certain ASCs. In the United States today, over 50% of Colonoscopy services are performed in ambulatory surgery centers.