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A medical code set that identifies health care procedures, equipment, and supplies for claim submission purposes. It has been selected for use in the HIPAA transactions. 

HCPCS Level I contains numeric CPT­4 codes which are maintained by the AMA. 

HCPCS Level II contains alphanumeric codes used to identify various items and services (such as: medical supplies, ambulance services, injectible drugs, and specific supplies) that are not included in the CPT­4 code set. These are maintained by HCFA, the BCBSA, and the HIAA. 

HCPCS Level III contains alphanumeric codes that are assigned by Medicaid state agencies to identify additional items and services not included in levels I or II. These are usually called "local codes", and must have "W", "X", "Y", or "Z" in the first position. 

HCPCS Procedure Modifier Codes can be used with all three levels, with the WA ­ ZY range used for locally assigned procedure modifiers.