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. STAT!Ref's version ICD-9-CM Vols. 1, 2, and 3, is geared toward hospitals and payers since Volume 3 contains procedure codes.

Volume 1 - The Tabular list
ICD9-CM codes and descriptions arranged numerically

Volume 2 - The Alpha Index
Diagnostic terms for encounters with healthcare professionals

Volume 3
The Alpha Index - common surgical and procedural terminology
The Tabular List - procedural codes arranged numerically