The International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) is based on the World Health Organization's Ninth Revision, International Classification of Diseases (ICD-9). ICD-9-CM is the official system of assigning codes to diagnoses and procedures associated with hospital utilization in the United States. The ICD-9 is used to code and classify mortality data from death certificates.
The ICD-9-CM consists of:
- a tabular list containing a numerical list of the disease code numbers in tabular form;
- an alphabetical index to the disease entries; and
- a classification system for surgical, diagnostic, and therapeutic procedures (alphabetic index and tabular list).
The National Center for Health Statistics (NCHS) and the Centers for Medicare and Medicaid Services are the U.S. governmental agencies responsible for overseeing all changes and modifications to the ICD-9-CM.