ADA and Direct Access Practice Test 2026 - Free ADA Exam Practice Questions and Study Guide

ICD stands for International Classification of Diseases. This is the globally used system published by the World Health Organization to classify diseases and a wide range of health problems for reporting, statistics, and billing. In practice, clinicians and coders often refer to ICD-10-CM for diagnoses in the United States and ICD-10-PCS for procedures, which together help track health trends and support reimbursement. The other phrases listed aren’t recognized names for this coding framework and don’t describe the standard method for coding diseases.