Transmittal 19-29 The purpose of this transmittal is to inform DC Medicaid Providers that each year the Centers for Medicare and Medicaid Services (CMS) releases modifications of the Healthcare Common Procedure Coding System (HCPCS) code set. Level I of the HCPCS are CPT (Current Procedural Terminology) codes, maintained by the American Medical Association, that are used primarily to identify medical services and procedures furnished by physicians and other health care professionals. Level II of the HCPCS is a standardized coding system that is used primarily to identify products, supplies, and services not included in the CPT codes, such as ambulance services and durable medical equipment.