Scoliosis is classified under the category of diseases of musculoskeletal system and immediate connective tissue, using numbers 710 through 739. Specifically, scoliosis can be coded as any code from ICD-9-CM 737.30 through ICD-9-CM 737.39, depending on the type of scoliosis in question.
The Mayo Clinic defines scoliosis as "a sideways curvature of the spine." The difference in codes for scoliosis is reflected in the last two digits to the right of the decimal point in the numeric code. The numeric differences reflect the cause of the scoliosis, or when the cause is unknown, the numeric code designates it as idiopathic.