Ambulatory Payment Classification (APC)
An Ambulatory Payment Classification (APC) groups outpatient hospital services into payment categories for Medicare's Outpatient Prospective Payment System.
Updated
An Ambulatory Payment Classification (APC) is a payment grouper used by Medicare's Hospital Outpatient Prospective Payment System to classify hospital outpatient services into categories that share similar clinical and cost characteristics. Each APC carries a federal rate that, with adjustments, produces the payment for the services in that group.
APCs apply to hospital outpatient departments — clinic visits, emergency department services, surgery, and other outpatient care — and bundle related services into a single payment rather than paying each line independently. A single encounter may span multiple APCs depending on the services furnished.
In practice
Because APC payment depends on the service codes reported and on packaging rules that fold related items into the primary service's payment, accurate coding and correct use of modifiers (such as those indicating distinct procedural services) affect both coverage and the amount paid. OPPS rules are revised annually, so the grouper logic and rates change over time.
Commonly confused with
- MS-DRG: An MS-DRG groups an inpatient hospital stay into a bundled payment; an APC groups an outpatient hospital service. Both are prospective payment groupers for different care settings.
- Physician Fee Schedule: The Physician Fee Schedule pays physician and clinical services (often under RVUs); APCs pay the hospital facility side of outpatient services. The same encounter can generate both a physician claim and a facility APC claim.