What is CMS-HCC V28 Transition Schedule? Definition, Formula, and Benchmark

The V28 Transition Schedule is the phased implementation of the CMS-HCC V28 risk adjustment model announced by CMS in the CY2024 MA Advance Notice and Rate Announcement. V28 replaces the prior V24 model, restructuring HCC definitions, weights, and aggregation logic. CMS implemented a three-year transition using blended V24/V28 weights: payment year 2024 uses 67% V24 / 33% V28; payment year 2025 uses 33% V24 / 67% V28; and payment year 2026 uses 0% V24 / 100% V28.

Key V28 changes from V24 include: HCC restructuring and renumbering (some HCCs consolidated, others split), removal of certain conditions from risk adjustment (e.g., morbid obesity, protein-calorie malnutrition in specific circumstances), lowered weights on several chronic conditions, tighter clinical criteria for some HCC-qualifying diagnoses, and overall model simplification based on CMS's analysis of coding intensity.

Financial impact on MA plans has been substantial. CMS projected and industry analysis confirmed that V28 reduces aggregate MA risk scores by approximately 3–4% compared to V24, translating to billions in revenue reduction across the MA industry. Individual plan impact varies by member population — plans with heavy concentrations of conditions affected by V28 (e.g., certain diabetic complication configurations, specific cardiovascular conditions) experience larger reductions than plans with different mix.

CMS's policy rationale for V28 includes: better alignment with current clinical practice (V24 was based on older data), reduction of documented coding intensity (CMS concluded V24 enabled gaming through specific diagnosis patterns), and simplification of risk adjustment (V24 had accumulated complexity over multiple updates). Industry response has been mixed: MA plans have advocated for delayed or partial transition citing operational and financial impact; CMS has maintained the transition schedule while making limited adjustments based on feedback.

Operational implications for MA plans include: recalibration of risk adjustment workflow priorities (conditions that matter for capture under V28 differ from V24), provider education updates, documentation and coding training reflecting V28 criteria, financial forecasting models incorporating V28 transition economics, and member risk score projection for care management targeting.

Provider and practice impact is indirect but material. Provider organizations in risk-bearing arrangements with MA plans experience revenue impact as risk scores change. Practices participating in MA ACOs or capitated arrangements see capitation adjustments reflecting V28 transition. Documentation and coding behaviors should reflect V28 weights and criteria, focusing capture effort on conditions that drive risk scores under the new model.

For RCM operations, V28 transition requires ongoing monitoring through 2026. Risk adjustment analytics should support V28 calculations alongside V24 to enable accurate financial modeling during the blend period. Coding and documentation workflows should align with V28 MEAT criteria for conditions that remain in the V28 HCC structure. Provider education should address V28 changes, particularly for primary care providers whose chronic-disease documentation drives risk scores.

Post-2026, V28 will be the sole risk adjustment model pending any subsequent CMS update. Industry speculation about V29 or subsequent model updates has begun; CMS typically provides multi-year lead time for major model changes, so any subsequent transition would likely not affect short-term operations. MA plans and participating providers should prepare for sustained V28 operations.