Risk Adjustment / CMS-HCC V28
V28, Fully Phased In: What the Final Blend Year Does to 2026 Risk Scores
CY2026 is the first payment year that runs on 100% CMS-HCC V28. The three-year blend is over, and the softening effect of the old V24 weights goes with it.
The phase-in, year by year
Three years to reach full weight
CMS introduced V28 in the CY2024 Rate Announcement and blended it against V24 on a fixed schedule. Each year the share of the risk score coming from V28 climbed. In 2026 it hits the top of the ramp and stays there.
V28 arrives, but two-thirds of the score is still calculated on V24. Plans and provider groups feel a nudge, not a shock. The remapped diabetes and vascular categories are mostly masked by the old weights.
The weighting flips. Now two-thirds of the score runs on V28, and the gaps left by dropped codes start showing up in year-over-year score trends. Groups that leaned on soft diabetes and vascular capture begin to see the drift.
No V24 left. The 2026 Medicare Advantage and Part D Rate Announcement (released April 7, 2025) confirms the final step. Every remap and removal now lands at full weight, on top of the statutory 5.90% minimum coding-pattern adjustment and the updated normalization factor. This is the year the model change is fully priced into revenue.
What changed under the hood
The V24 to V28 structural shift
Category and code counts reflect CMS-HCC model V28 as published in the CY2024 Rate Announcement and carried through the CY2026 Rate Announcement. Figures describe the model structure, not any single plan's results.
Where the 2026 hit concentrates
The HCC categories that move scores the most
Not every condition changed. The revenue impact clusters in a handful of high-volume categories where V28 either remapped the code to a lower coefficient or removed it from payment entirely. A few categories actually improved. Here is where to look first.
Diabetes
Highest-volume category in most panels, so small per-member changes scale fast.
Under V24
- Separate, higher-weight buckets for diabetes with complications
- Vague diabetes still captured meaningful value
Under V28 (2026)
- Diabetes categories consolidated with a flatter coefficient
- The old complication differential is compressed, so unspecified diabetes loses ground unless the linked complication is coded to specificity
Vascular disease and atherosclerosis
Peripheral vascular and several atherosclerosis codes no longer stand alone.
Under V24
- Peripheral vascular disease mapped to a payment HCC
- Atherosclerosis without complication carried weight
Under V28 (2026)
- Many of these codes drop out of the payment HCC set
- Value now depends on documenting the downstream event or complication, not the underlying vascular diagnosis alone
The unmapped-code block
Roughly 2,000+ ICD-10 codes that used to map now map to nothing.
Under V24
- Broader code-to-HCC crosswalk captured softer documentation
Under V28 (2026)
- Coders keep submitting the same codes, but they no longer generate a payment HCC
- The loss is invisible on the claim, which is why it survives into the blend's final year
Chronic kidney disease, stage 3
One of the categories that V28 expanded rather than cut.
Under V24
- Earlier-stage CKD often fell outside the payment set
Under V28 (2026)
- CKD stage 3 is recognized in the payment model
- An offset for panels that document renal staging cleanly, so the lab-to-code workflow is worth the effort
What operators should do before year-end
Turning the model change into a work plan
Re-map your top codes
Run your highest-volume diagnosis codes against the V28 crosswalk and flag the ones that no longer produce a payment HCC.
Tighten diabetes capture
Where a complication exists, document and code it to specificity so the linked condition carries the value the flat diabetes weight no longer does.
Chase the expansions
Build a lab-to-code loop for CKD staging and the other categories V28 added, so you capture the offsets you are now entitled to.
Re-baseline the model
Reset revenue expectations to a 100% V28 run rate. Any forecast still carrying blended assumptions from 2024 or 2025 is now optimistic.
Know your 2026 exposure before it hits the remittance
ASP-RCM Solutions re-maps your active diagnosis panel against V28, quantifies the categories bleeding value in the first full-weight year, and builds the documentation and coding workflow to recover it. No fabricated projections, just your codes against the current model.
Request a V28 impact read → or talk to a risk-adjustment leadRelated reading
The codes moved. The weight moved with them.
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