Mappings between the ICD-9-CM and ICD-10 code sets can play a critical role in the successful conversion of systems and applications to the new code sets. But because there are no equivalents between the two systems, using mappers will be no easy task. This session will help users become familiar with the general equivalency mappers (GEM) and other available resources, help them use mappers to educate coders and others, and help them determine which mapper to use.