HCC Model Versions: V28 and V24
CMS uses Hierarchical Condition Category (HCC) models to calculate risk-adjusted payments for Medicare Advantage plans. These models map ICD-10-CM diagnosis codes to HCC categories, apply RAF (Risk Adjustment Factor) weights, and enforce hierarchy exclusion rules that prevent double-counting of related conditions.
The CMS HCC V28 model is the updated version that CMS introduced to better reflect current clinical coding patterns and cost relationships. It includes revised HCC groupings, updated ICD-10-CM mappings, recalibrated RAF coefficients, and modified hierarchy rules. V24 is the predecessor model that remains relevant during the multi-year transition period, as CMS uses a phased blend of both models for payment calculations.
For organizations performing RADV HCC validation or prospective chart review, supporting both model versions is not optional. A code that maps to a valid HCC under V24 may map differently—or not at all—under V28. RAF weights differ between models. Hierarchy exclusion rules have changed. Getting any of these wrong creates compliance risk and potential payment discrepancies.
How RafCite Handles Dual Model Versions
RafCite™ natively supports both CMS HCC V28 and V24, applying the correct model logic based on the payment year configuration:
V28 Transition Readiness
The CMS transition from V24 to V28 affects every aspect of risk adjustment operations. Organizations that rely on tools built only for V24 face growing compliance gaps as V28 takes on a larger share of the blended payment calculation each year.
RafCite helps organizations manage the V28 transition by providing:
- Side-by-side model comparison — See how a chart’s HCC profile and RAF score differ between V28 and V24, identifying codes that gain, lose, or change category
- Mapping gap identification — Flag ICD-10-CM codes that no longer map to an HCC under V28, or that map to a different category than under V24
- Hierarchy change alerts — Identify cases where V28 hierarchy rules produce different exclusion outcomes than V24 for the same set of HCC codes
- Payment impact visibility — Understand how the model transition affects RAF scores for your member population before payment reconciliation
No manual model lookups. RafCite maintains both model versions internally. Your coding and compliance staff work with the structured output rather than cross-referencing CMS mapping tables manually.
Technical Capabilities
RafCite’s dual model support includes the following specific capabilities for CMS HCC V28 and V24:
- Complete ICD-10-CM to HCC crosswalks for both V28 and V24, updated with each CMS publication cycle
- Full RAF coefficient tables including community, institutional, new enrollee, and SNP segments
- Disease interaction calculations reflecting model-specific interaction terms (e.g., diabetes + CHF interactions)
- Hierarchy exclusion engine that processes the complete hierarchy tree for each model version
- Payment year configuration supporting current year, prior year, and custom year selections
- Blended score output for transition years, providing V28 score, V24 score, and the applicable blend ratio
- Model version flagging on every HCC in the evidence packet, so reviewers know which model applies to each finding
All model data is maintained as versioned configuration within your on-premise deployment. Updates are delivered as part of your annual platform license.
Frequently Asked Questions
What is the difference between CMS HCC V28 and V24?
CMS HCC V28 is the updated risk adjustment model that CMS introduced to replace V24. V28 includes revised HCC categories, updated ICD-10-CM mappings, modified RAF weights, and new hierarchy exclusion rules. V24 remains relevant because CMS uses a phased blend of both models during the transition period, with payment years using different blend ratios of V24 and V28 calculations.
How does RafCite stay current with CMS model updates?
RafCite’s model tables—including ICD-10-CM to HCC mappings, RAF coefficients, and hierarchy exclusion rules—are maintained as versioned configuration that is updated when CMS publishes new rate announcements and model revisions. Updates are delivered as part of your platform license and applied on-premise without sending any data externally.
Does RafCite calculate RAF scores for both V28 and V24?
Yes. RafCite calculates RAF weights under both CMS HCC V28 and V24 models. It applies the correct demographic coefficients, disease interaction factors, and hierarchy exclusion rules for each model version. For payment years that use a blended calculation, RafCite provides the individual model outputs so your team can verify the blended result.
When will CMS complete the transition from V24 to V28?
CMS has implemented the V28 transition using a phased blend approach across multiple payment years. The specific blend ratios and full transition timeline are defined in the annual CMS Rate Announcement. RafCite supports both models throughout the transition period so your organization can validate HCC documentation under whichever model version applies to a given payment year.
Related Pages
Stay Current with HCC Model Updates
See how RafCite handles CMS HCC V28 and V24 model versions with automatic RAF calculation and hierarchy exclusion—all running on your infrastructure.