CPT Codes
HCPCS Codes
ICD-10-CM Codes
ICD-10-PCS Codes
APCs
DRGs and MS-DRGs

CPT stands for Current Procedural Terminology, a code set that healthcare providers use to identify procedures provided to patients. The CPT code includes three main categories, Category I CPT codes make up the bulk of the CPT code set. Category II codes are supplemental tracking codes, meaning they assist with data collection related to performance measures. Category III includes temporary codes for emerging technology, services and procedures.

The Healthcare Common Procedure Coding System (HCPCS) has two main levels. Level I is the AMA’s CPT codes and Level II is the code set that most people think of as simply the HCPCS code set.

International Classification of Disease, tenth Revision, Clinical Modification (ICD-10-CM) is based on the World Health Organization’s ICD-10 statistical classification disease. The National Center for Health Statistics (NCHS) is responsible for use of ICD-10 in the US.

The International Classification of Diseases, Tenth Revision, Procedure Coding System (ICD-10-PCS) is a code set adopted under the Health Insurance Portability and Accountability Act (HIPAA) for hospital inpatient healthcare settings. ICD-10-PCS replaced ICD-9-CM for medical claim reporting purposes.

Ambulatory Payment Classifications (APCs) are the typical unit of payment for Medicare’s Outpatient Prospective Payment System (OPPS). CMS assigns items and services to APCs based on costs and characteristics. CMS assigns a payment rate to the APC, and that rate applies to each service in the APC.

Diagnosis-related groups (DRGs) are a classification system for inpatient discharge billing. MS-DRGs are Medicare Severity DRGs, which were developed for classifying claims for Medicare patients.