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

Prior to 2003, "E codes" are included in the diagnosis array (DXn) with CCS values in the corresponding array DXCCSn. From January 2003 to September 2015 , 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. For data beginning in the fourth quarter of 2015, ICD-10-CM external cause of morbidity codes are stored the data element I10_DXn with the corresponding array of I10_ECauseCCSn to indicate the implementation of the ICD-10-CM/PCS coding system.

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.