ICD-10 R21 Conversion to ICD-9 782.1
ICD-10 to ICD-9 Crossover Result
ICD-10 Code R21 representing "Rash and other nonspecific skin eruption" can be backward-mapped to its ICD-9 equivalent 782.1: "Nonspecif skin erupt NEC". This is a direct match with no additional mapping qualifiers. The absence of a flag generally means the mapping is considered exact or precise. In other words, the ICD-10 code maps cleanly to the ICD-9 code without qualification, approximation, or needing multiple codes. This conversion was generated using the latest General Equivalence Mappings (GEMs). While these mappings provide a standardized reference, not all ICD-10 codes have an exact ICD-9 match. Review the table below carefully and consider the clinical context when interpreting the mapped codes.
About the General Equivalence Mappings Crossover Tool
The General Equivalence Mappings tool is a standardized crossover resource developed by the Centers for Medicare & Medicaid Services (CMS) and the National Center for Health Statistics (NCHS). It was created to help healthcare providers, coders, payers, and software vendors accurately transition between ICD-9 and ICD-10 diagnosis codes.
This ICD-10 to ICD-9 crosswalk tool supports both forward and backward mapping, making it valuable for converting legacy data, conducting audits, updating medical coding systems, and ensuring compliance with ICD-10 standards. GEMs are especially helpful when analyzing historical claims, aligning reimbursement logic, or migrating between systems.
Because not all ICD codes have a direct match, users should interpret each mapping carefully. Some ICD-10 to ICD-9 conversions may require clinical judgment or additional documentation to ensure coding accuracy.
