The V28 risk adjustment model is fully implemented for payment year 2026. Here is what changed from V24, how it affects RAF scores, and what to plan for in 2027.
Let's talkCMS-HCC V28 is the current version of the Medicare Advantage risk adjustment model, which CMS uses to translate a patient's documented diagnoses into a risk score that drives payment.
CMS phased V28 in over three years and reached 100% implementation for payment year 2026, fully replacing the older V24 model. V28 was rebuilt on more recent ICD-10 data, which changed which diagnoses count and how much each is worth.
The model expanded from roughly 86 payment HCCs under V24 to 115 under V28, with new numbering. Old and new HCC numbers are not interchangeable.
V28 reduced the set of ICD-10-CM codes that map to an HCC from about 9,797 to roughly 7,770. Some diagnoses that raised RAF under V24 no longer do.
Many conditions carry different risk weights under V28, so the same patient can produce a different RAF score than under V24.
With fewer codes qualifying, complete, current, MEAT-supported documentation matters more than ever to capture the conditions that still count.
Because V28 dropped qualifying codes and re-weighted others, organizations that do not update their coding workflows can see RAF scores drift lower even when clinical acuity has not changed.
Heading into 2027, the priority is capturing every condition that still counts under V28, with the documentation to support it. That favors real-time, point-of-care coding tied to a documented encounter, especially as CMS also moves to exclude unlinked chart review diagnoses from risk adjustment.
Inferscience is maintained against the current CMS-HCC V28 model, so your coding reflects the categories and weights that actually count for 2026 and 2027.
HCC Assistant surfaces missed and suspected HCCs at the point of care at 98% coding accuracy, and HCC Validator confirms every diagnosis meets MEAT criteria before submission. A 700-provider clinically integrated network has coded with Inferscience inside athenaOne since 2020. Read the case study →
CMS-HCC V28 is the current Medicare Advantage risk adjustment model. It reached 100% implementation for payment year 2026, replacing the V24 model, and it changed which diagnoses count toward risk scores and how much each is worth.
V28 expanded payment HCCs from about 86 to 115 with new numbering, reduced the mapped ICD-10-CM codes from about 9,797 to roughly 7,770, and re-weighted many conditions. Some diagnoses that raised RAF under V24 no longer do.
CMS phased V28 in over three payment years and reached 100% implementation for payment year 2026.
Because fewer codes qualify and many are re-weighted, RAF scores can decline even when patient acuity is unchanged, unless coding and documentation are updated to capture the conditions that still count under V28.
Use coding tools maintained against the current model. Inferscience's HCC Assistant and HCC Validator are kept current with CMS-HCC V28 so your coding reflects the categories and weights in effect for 2026 and 2027.
See how Inferscience keeps your RAF scores accurate under the current model.
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