Medical conditions for which physicians broadly concur that a substantial proportion of these cases should not advance to the point where hospitalization is necessary if the patients are treated in a timely fashion with adequate primary care and managed properly on an outpatient basis.

Individual who is receiving medical services and is able to walk or ambulate in a wheelchair.

Classification system by case types used until 2000 as a payment method developed for the Centers for Medicare and Medicaid Services (CMS). It was replaced with ambulatory surgery categories (ASCs) and later replaced by the ambulatory payment classification (APC) system.

1. Method developed by the Centers for Medicare and Medicaid Services (CMS) for outpatient hospital reimbursement based on procedures that have similar clinical characteristics and similar costs rather than on diagnoses. 2. Medicare’s outpatient prospective payment system (OPPS) for hospital outpatient services that became effective August 1, 2000. Depending on the services given, hospital facilities may be paid for more than one APC for an encounter. APC information is updated and released twice a year in the Federal Register. Also called ambulatory payment classes, ambulatory patient classifications (APCs), and ambulatory patient care groups.

Operative procedure performed on a patient as an outpatient in which he or she is admitted, treated, and released on the same day from the facility. Also referred to as outpatient surgery.

ASCs were adopted to replace ambulatory patient groups (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.