Risk Adjustment Intelligence · CMS-HCC V28

V28 hits full weight in 2026. The blend that cushioned you is gone.

For two years a phase-in blend softened the model change. In payment year 2026 that cushion reaches zero. Every risk score your group carries is now scored on V28 alone, and the codes that used to earn weight under V24 no longer all do.

Share of the risk score priced on V28Source: CY2024–CY2026 MA & Part D Rate Announcements

2024V28 phase-in begins

33% V28 · 67% V24

2025Blend tilts to V28

67% V28 · 33% V24

2026Transition complete

100% V28 · 0% V24

The short version: if your 2026 risk scores dropped and your documentation did not, you are almost certainly seeing the V28 remap, not a coding failure. The CMS-HCC V28 model was rebuilt on ICD-10-CM, it moved diagnoses between HCCs, and it removed thousands of ICD-10-CM codes from payment status entirely. Charts that were compliant and complete under V24 can now score lower for the exact same patient. The fix is not more aggressive coding. It is re-mapping your active population to V28 before the plan does it for you.

The Stat Wall

Six numbers that explain the quiet score erosion

86 → 115

Payment HCCs

V28 expands the condition set from 86 to 115 HCCs. More categories, but narrower doors into each. CMS-HCC V28

~7,770

ICD-10-CM codes still carrying weight

Down from roughly 9,797 under V24. Around 2,000 codes that once mapped to a payment HCC no longer do. CMS V28 model docs

V24 remaining in 2026

The 33% / 67% / 100% phase-in ends. No blended backstop remains. CY2026 Rate Announcement

V2.7

ICD-10-CM classification base

V28 is built on an ICD-10-CM foundation, not the older ICD-9-era logic V24 inherited. The crosswalk itself changed. ICD-10-CM → HCC map

High-volume categories remapped

Diabetes, vascular disease, and specific mental-health / substance categories moved or lost differentiation. High-frequency conditions, so small per-chart shifts scale fast.

1×

Chance to re-baseline cleanly

2026 is the first full-V28 year. Re-map your active panel once, now, and every downstream sweep inherits the correction.

Where a compliant chart loses ground

Same diagnosis, different weight

Illustrative of the direction of change under the CMS-HCC V28 model. Exact coefficients vary by segment and are published in the CMS model files. The pattern, not the decimal, is the point.

Clinical area	Under V24	Under V28 (2026)	What changed
Diabetes without complication	Mapped to a diabetes HCC with its own weight	Consolidated / narrowed differentiation vs. complicated diabetes	↓ Uncomplicated codes lose the separation they once earned
Vascular disease (selected atherosclerosis codes)	Several codes drove a payment HCC	Subset dropped from payment status or remapped	↓ Codes that used to score now return zero weight
Depression / selected behavioral codes	Broad set qualified	Tighter specificity required to land the HCC	↓ Unspecified documentation stops mapping
Category structure overall	86 payment HCCs	115 payment HCCs, renumbered	⇄ Your old HCC numbers no longer line up one-to-one

The failure pattern

How a group that coded fine ends up short

Documentation held

Providers charted the same conditions, the same way, with the same specificity as last year.

The map moved under it

V28 dropped or remapped the codes those charts relied on. Nobody changed behavior, so nobody noticed.

The blend hid it in 24–25

Residual V24 weight kept scores from falling sharply. The signal was muffled by design.

2026: the muffler comes off

At 100% V28, the erosion prints at full size in your revenue. If you are only reading it now, you are reading it a year late. The read is not "code harder," it is "re-map the panel and recapture where V28 still rewards specificity you already have in the record."

Grounded in the real rules

What we track this against

MODEL CMS-HCC V28 risk-adjustment model 2026 CY2026 Medicare Advantage & Part D Rate Announcement 2025 CY2025 MA & Part D Rate Announcement (67% V28 blend) 2024 CY2024 MA & Part D Rate Announcement (phase-in begins) MAP ICD-10-CM to CMS-HCC mapping changes

We pull weights and mappings from the published CMS model files, not from memory or vendor summaries, so the number your engine returns is the number CMS will pay on.

See your panel re-scored on V28 before the plan does

Our HCC / Risk-Adjustment engine (V28) re-maps your active population against the current CMS-HCC V28 model, flags every condition that lost or shifted weight, and surfaces the specificity already sitting in your charts that V28 still rewards. You get the erosion quantified and the recapture list, not a slideshow.

Request a V28 erosion read

De-identification runs before any protected health information leaves your environment. Figures on this page describe the direction and structure of the CMS-HCC V28 changes; exact coefficients and code counts are published in the CMS model files and the CY2024–CY2026 Medicare Advantage & Part D Rate Announcements. Client examples are archetypes, not named accounts.