All terms
Ambulatory Payment Classification
The Medicare grouping system that determines hospital outpatient payment amounts under OPPS, analogous to MS-DRGs for inpatient.
Reviewed by Christian Espinosa, Founder, Blue Goat CyberLast reviewed May 9, 2026
Definition
Ambulatory Payment Classifications (APCs) are the unit of payment under the Medicare Hospital Outpatient Prospective Payment System (OPPS), established by the Balanced Budget Act of 1997 and effective August 2000. CMS groups outpatient procedures with similar clinical characteristics and resource use into APCs and pays a single bundled amount per APC, with status indicators that determine whether the service is separately payable, packaged into another APC, or excluded. What the regulation says
OPPS rules are issued annually in the OPPS Final Rule (calendar-year cycle). 42 CFR 419 governs the system. CMS publishes the APC list and status indicators in OPPS Addendum B.
What this means in practice
APC assignment plus pass-through status (TPT) determines the outpatient economics of a new device. Many MedTech launch strategies hinge on securing a favorable APC and, where eligible, transitional pass-through payment. Common pitfalls
- •Assuming an inpatient NTAP equivalent exists in OPPS — it does not; the outpatient analog is TPT.
- •Missing the annual OPPS comment window (June-September) for APC reassignment requests.
Primary references
3 sourcesLink health: 2 verified 1 needs review· last checked 2026-05-09
CMS·2eCFR·1
- 1
CMS — Hospital OPPSVerifiedCMScms.gov
- 2
42 CFR 419VerifiedeCFRecfr.gov
- 3
CMS - CoverageNeeds reviewCMScms.gov
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