CY 2026 CMS-HCC Risk Adjustment: V28 Is Now 100%

Quick answer

CMS says CY 2026 completes the phase-in of the 2024 CMS-HCC risk adjustment model for organizations other than PACE. In coder shorthand, V28 is now the main CMS-HCC reality for non-PACE Medicare Advantage risk scores.

That does not mean every familiar diagnosis suddenly maps the way your team expects. It means the old blended V24/V28 transition is no longer the safe mental model. Coders need to check the ICD-10-CM code path, the 2026 CMS-HCC mapping, and the provider documentation before treating any RAF impact as real.

The safe order is simple:

1. Confirm the diagnosis is supported in the provider note.

2. Verify the ICD-10-CM code path and full code in the current code set.

3. Check the 2026 CMS-HCC mapping and hierarchy impact.

4. Review MEAT-style documentation before the code is accepted for risk adjustment.

What CMS changed for 2026

CMS published CY 2026 risk adjustment implementation information stating that, for organizations other than PACE, risk scores are calculated using 100 percent of the 2024 CMS-HCC model. That is the model many coders call V28.

CMS also publishes the 2026 Model Software and ICD-10 Mappings, which is the source to use when you need to confirm whether an ICD-10-CM code maps to a CMS-HCC for the payment year.

The important coder takeaway is not just "V28 is here." It is that the mapping check has to happen after the coding check. A diagnosis can appear clinically important and still fail one of the steps that makes it reportable for risk adjustment.

PACE is different

Do not generalize the non-PACE statement to every program. CMS separates PACE in the CY 2026 implementation materials. If you code or audit for PACE, verify the applicable model instructions before using the same V28 shorthand your Medicare Advantage team uses.

For most non-PACE MA work, though, the transition period is over. Team education, internal QA, provider queries, and RAF review should be built around the current model rather than a blended V24/V28 comparison.

Code path first, HCC mapping second

The biggest mistake is starting with the HCC and working backward. V28 mapping is not permission to code a diagnosis. It is only the downstream answer after the ICD-10-CM code is valid and supported.

Before you look at RAF impact, check:

CMS keeps the current ICD-10-CM files and Official Guidelines available for this reason. The HCC mapping file answers one question. The ICD-10-CM code set and guidelines answer a different one.

Where V28 creates more cleanup work

V28 makes weak specificity easier to spot. A code that felt familiar under V24 may not behave the same way under the 2024 CMS-HCC model. That matters most in condition families where provider wording and code specificity drive the outcome.

High-friction areas for HCC teams include:

The point is not to chase higher RAF. The point is to code what the note supports and then understand how the current model treats that code.

Documentation still decides whether the code survives

MEAT is still the practical review lens: Monitor, Evaluate, Assess, Treat. Coders do not need every element in every note, but they need enough current documentation to defend that the condition was addressed.

A problem-list mention by itself is not the same as supported risk adjustment documentation. Before accepting an HCC-relevant code, ask whether the note shows current clinical attention to the condition. Look for labs, imaging, symptoms, status, assessment, medication management, referrals, orders, counseling, or care-plan changes.

If the note does not carry the diagnosis, the mapping file should not talk the coder into keeping it.

Practical V28 workflow for coding teams

Use this as a fast QA loop:

1. Validate the ICD-10-CM code. Confirm the code exists for the service date and is billable at the required specificity.

2. Check the Tabular instructions. Do not skip Excludes notes, sequencing instructions, or required additional codes.

3. Confirm current documentation. Make sure the provider note supports the condition and the selected specificity.

4. Map under the current model. Use the 2026 CMS-HCC mapping to confirm whether the code maps and whether hierarchy logic changes the result.

5. Model RAF last. RAF belongs after code validity and documentation support, not before.

HCC Buddy can help with that workflow. Use the ICD-10 encoder to check code details and V24/V28 context. Use ICD-10 to HCC mapping to verify whether a diagnosis maps under the current model. Use the RAF calculator only after the code is defensible. Use Evidence Checker and Smart Notes when documentation support needs a closer look.

Bottom line

CY 2026 is not the year to rely on memory from the blended transition. Use the current ICD-10-CM files, the current CMS-HCC mappings, and the provider note in front of you.

V28 is the model reality for most non-PACE Medicare Advantage risk scores. Coder judgment still comes first.