ASC stands for Ambulatory Surgery Center. They are a facility (similar in respect to a Hospital, outpatient services). Some practices have them and do procedures there instead of the hospital. I know some GI doctors, Pain Management doctors have them. Plus, many cities are having surgery centers and alot of times these are ASC's. They provide outpatient services/procedures to patients, without the patients having to go the hospital and having them done as outpatient.

Hope this helps, so to ramble on.
ASC are also 'free standing facilities' where the surguries are elective. At our center we do many as GI, podiatry, opthalmology,plastic surgery, pain management, urology, etc.:cool: