Ambulatory Payment Classifications (APCs) are similar to Diagnosis-Related Groups (DRGs) in which of the following...

APCs and DRGs are both prospective payment classification systems designed to group services that consume similar resources, supporting standardized reimbursement. DRGs group inpatient stays largely around the principal diagnosis, key procedures, complications/comorbidities, and discharge status to estimate expected hospital resource use for the admission. APCs, used primarily for hospital outpatient services, group billable procedures and services that are clinically comparable and expected to require similar levels of resources (staff time, supplies, equipment, intensity). While APCs often allow multiple payment classifications within a single outpatient encounter (because multiple procedures may be performed), that feature is not the fundamental similarity to DRGs—it’s a key difference in operational payment mechanics. Likewise, APC assignment is generally driven by CPT/HCPCS and revenue codes rather than being primarily diagnosis-dependent. The shared concept emphasized in outpatient CDI education is that both systems aim to align payment with anticipated resource utilization, which is why complete, accurate documentation is essential to support correct coding of the services and conditions that justify the level of care provided.