ICD-9-CM codes have the periods removed. Diagnostic codes are prefixed with
'D' while procedure codes are prefixed with 'P'. So, diagnostic code
404.03 appears as
A string vector
Obsolete codes not active in 2012 are not present, and may cause this dataset to miss certain classifications when applied to older datasets. For example, codes 043 and 044 (both obsolete AIDS codes) are not included.