GEMs crosswalk: ICD-9-CM ↔ ICD-10-CM

Look up the General Equivalence Mappings (GEMs) published by CMS and NCHS in both directions: forward (ICD-9-CM to ICD-10-CM) and backward (ICD-10-CM to ICD-9-CM), with the flags that show approximate matches, no-map entries and combinations. GEMs translate data between code sets; they do not replace coding from the medical record. How GEMs and the FY update cycle work.