General Equivalence Mappings of ICD 9 to ICD 10

What are the General Equivalence Mappings?

The GEMs are a tool that can be used to convert data from ICD-9-CM to ICD-10-CM and PCS and vice versa. Mapping from ICD-10-CM and PCS codes back to ICD-9-CM codes is referred to as backward mapping. Mapping from ICD-9-CM codes to ICD-10-CM and PCS codes is referred to as forward mapping. The GEMs are a comprehensive translation dictionary that can be used to accurately and effectively translate any ICD-9-CM-based data, including data for:

*  Tracking quality;
*  Recording morbidity/mortality;
* Calculating reimbursement; or
*  Converting any ICD-9-CM-based application to ICD-10-CM/PCS.


The GEMs are complete in their description of all the mapping possibilities as well as when there are new concepts in ICD-10 that are not found in ICD-9-CM. All ICD-9-CM codes and all ICD-10-CM/PCS codes are included in the collective GEMs:

*  All ICD-10-CM codes are in the ICD-10-CM to ICD-9-CM GEM;
*  All ICD-9-CM Diagnosis Codes are in the ICD-9-CM to ICD-10-CM GEM;
* All ICD-10-PCS codes are in the ICD-10-PCS to ICD-9-CM GEM; and
*  All ICD-9-CM Procedure Codes are in the ICD-9-CM to ICD-10-PCS GEM.