How ICD-10 Codes Are Converted Into Medicare Advantage RAF Scores

In Medicare Advantage risk adjustment, ICD-10-CM diagnosis codes do not carry individual risk scores — they must first be mapped to Hierarchical Condition Categories (HCCs) before a Risk Adjustment Factor (RAF) score can be calculated. The process involves applying a hierarchy rule that retains only the most severe HCC within a disease family, preventing double-counting of related conditions. The final RAF score combines a demographic factor, coefficients for each surviving HCC, and interaction terms for specific disease combinations. Critically, CMS updates the HCC maps and coefficients annually, meaning the same set of diagnosis codes can produce different scores depending on which model version — such as V24 or V28 — is applied. Implementers are advised to always validate their crosswalk tables against the current CMS Rate Announcement to avoid scoring errors.