What Is APC (Ambulatory Payment Classification)?
An APC is the hospital outpatient classification system used by CMS under the Outpatient Prospective Payment System (OPPS) to group similar outpatient services for prospective payment to hospitals.
- Hospital outpatient billing requires understanding which services are status-indicator T (significant procedure, payable separately), N (packaged into other services), or Q (conditionally packaged).
- Misclassifying a packaged service as separately payable creates compliance risk and inflated charges.
APC (Ambulatory Payment Classification)
Also known as: Ambulatory Payment Classification
An APC is the hospital outpatient classification system used by CMS under the Outpatient Prospective Payment System (OPPS) to group similar outpatient services for prospective payment to hospitals.
Definition
Implemented in 2000, the APC system is the outpatient analog to the inpatient DRG system. Each HCPCS/CPT code performed in a hospital outpatient setting maps to an APC, and each APC has a relative weight. The hospital's payment is the APC weight times the OPPS conversion factor, adjusted for wage index. Some APCs use 'comprehensive APC' (C-APC) bundling, where ancillary services on the claim are packaged into a single payment. APCs are updated annually in the OPPS Final Rule. APCs apply to hospital outpatient departments, including hospital-based clinics, but not to physician professional services or ASCs (which have their own ASC payment system).
Example
CPT 92928 (PCI with stent) performed in a hospital outpatient cath lab maps to a C-APC that bundles the procedure, contrast, supplies, and most ancillaries into a single payment of approximately $13,000-15,000. The same procedure performed in a hospital inpatient setting is paid via MS-DRG instead.
Common Misconceptions
APCs apply only to the hospital's facility fee on hospital outpatient claims (UB-04), not to the physician's professional fee for the same encounter. The physician's professional fee for the same procedure is paid separately under the MPFS using RVUs.
Practical Application
Hospital outpatient billing requires understanding which services are status-indicator T (significant procedure, payable separately), N (packaged into other services), or Q (conditionally packaged). Misclassifying a packaged service as separately payable creates compliance risk and inflated charges.
Related Terms
DRG (Diagnosis-Related Group)
A DRG is the inpatient hospital classification system that groups admissions with similar clinical characteristics and resource use into a single payment category; CMS uses MS-DRGs to pay hospitals under the IPPS for Medicare inpatient stays.
Read definition arrow_forwardCPT (Current Procedural Terminology)
CPT is the five-digit procedural code set developed and maintained by the American Medical Association that describes medical, surgical, and diagnostic services performed by physicians and qualified health professionals; it is HIPAA-named for use in claims.
Read definition arrow_forwardUB-04 form
The UB-04 (also known as CMS-1450) is the standard paper claim form used by institutional providers (hospitals, SNFs, home health, hospice) to bill Medicare and other payers; its electronic equivalent is the 837I (Institutional) HIPAA EDI transaction.
Read definition arrow_forwardCMS
CMS is the federal agency within the U.S. Department of Health and Human Services that administers Medicare, jointly administers Medicaid and CHIP with the states, and oversees the Health Insurance Marketplaces and HIPAA administrative simplification.
Read definition arrow_forwardWhere This Applies on MedPrecision
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