Services' (CMS) list of ambulatory payment classifications of hospital outpatient services. (c) Ambulatory Surgical Center (ASC) means any surgical clinic as defined in the California. Health and Safety Code Section 1204, subdivision (b)(1), any ambulatory surgical center that is cer-. tified to participate in the Medicare program under Title XVIII (42 U.S.C. SEC. 1395 et seq.) of the.