Difference Between CPT Codes & ICD-9 Codes

Medical billers and coders primarily use codes from two manuals: the "International Classification of Diseases (ICD)" manual and the "Current Procedural Terminology (CPT)" manual. These books contain thousands of numerical and alphanumerical codes to apply to insurance forms.

CPT Codes

• The CPT book lists codes for reporting medical services and procedures, including diagnostic, laboratory, radiology, surgical and many others.

ICD Codes

• The ICD manual includes codes that identify the particular diagnosis. These codes describe a disease or condition. The United States uses the ninth revision, or ICD-9, but many countries use the 10th revision.

Publishers

• The CPT manual is published by the American Medical Association, while the ICD book is published by the World Health Organization.

Relationships

• As many as four ICD-9 codes can be linked to one CPT code on a standard HCFA-1500 insurance claim form.

Number of Codes

• The CPT manual has about 7,800 codes, compared with 24,000 in the ICD-9. The ICD-10 has more than 200,000 codes.