The Procedure Classes provide users an easy way to categorize ICD-9-CM procedure codes into one of four broad categories:

• Minor Diagnostic: Non-operating room procedures that are diagnostic (e.g., 87.03 CT scan of head)
• Minor Therapeutic - Non-operating room procedures that are therapeutic (e.g., 02.41 Irrigate ventricular shunt)
• Major Diagnostic - All procedures considered valid operating room procedures by the Diagnosis Related Group (DRG) grouper and that are performed for diagnostic reasons (e.g., 01.14 Open brain biopsy)
• Major Therapeutic - All procedures considered valid operating room procedures by the Diagnosis Related Group (DRG) grouper and that are performed for therapeutic reasons (e.g., 39.24 Aorta-renal bypass).

More information on the Procedure Class is available under Tools & Software on the HCUP-US website.