Facility’s schedule for the performance of elective surgical procedures on patients admitted and discharged on the same day the procedure is performed.

Evaluation and analysis of the medical necessity, appropriateness, and efficiency of medical services given in an ambulatory facility. Utilization review is typically performed by a utilization review committee.

AVGs were replaced by ambulatory patient groups (APGs) as an outpatient classification system by Health Systems International (HSI). Then ambulatory surgery categories (ASCs) were adopted, replacing APGs for outpatient or 1-day surgery cases that were derived from the surgery section of the CPT. Later this was replaced by the ambulatory payment classification (APC) system.