These are based on the level of care rendered. Each facility class has minimal equipment required on site.
Class A facility: Provides for minor surgical procedures performed under topical, local, or regional anesthesia without preoperative sedation. Excluded are intravenous, spinal, and epidural routes; these methods are appropriate for Class B and C facilities.
Class B facility: Provides for minor or major surgical procedures performed in conjunction with oral, parenteral, or intravenous sedation or under analgesic or dissociative drugs.
Class C facility: Provides for major surgical procedures that require general or regional block anesthesia and support of vital bodily functions.
There are three levels of anesthesia and surgery and three classes of surgical facility. While correlated they are separate.