Clinical Classifications Software (CCS) consists of over 260 diagnosis categories. This system is based on ICD-9-CM codes. All diagnosis codes including external cause of injury codes "E codes" are classified.

Prior to 2003, external cause of injury codes "E codes" are included in the diagnosis array (DXn) with CCS values in the corresponding array DXCCSn. Beginning in 2003, any separately reported E codes and any E codes encountered in the diagnosis array are placed in a separate array specific to E codes (ECODEn). The corresponding array E_CCSn contains the CCS category.

In the CCS, E codes are classified into 20 categories (values 2601-2621). E_CCSn is missing (.), if there is no E code (ECODEn = " "). E_CCSn is set to invalid (.A), if the E code (ECODEn) is invalid by the HCUP criteria.

Labels

Labels for CCS categories are provided as an ASCII file in HCUP Tools: Labels and Formats.

Formats

Formats to label CCS categories are documented in HCUP Tools: Labels and Formats. A format is also available to map CCS codes into a few broad classes of conditions based on ICD-9-CM chapters.