Risk Adjustment Model · Hub
CMS-HCC V28
CMS-HCC V28 is the 2026 Medicare Advantage risk adjustment model. Payment year 2026 is the first year without a V24 blend, which means every HCC on every submitted claim is now evaluated against the V28 category map, the V28 hierarchy rules, and the 2026 V28 coefficient set published in the April 2025 CMS Rate Announcement.
This hub covers what V28 is, what changed from V24, the full 2026 HCC list, which category families gained or lost RAF weight, and how coders should retool chart review workflows for 100% V28.
Quick answer
V28 contains 115 payment HCC categories, a 67/33 → 33/67 → 0/100 V24/V28 phase-in from payment year 2024 to 2026, and a 2026 coefficient set that is on average 3.2% lower than V24 for the same condition list. The RAF impact per contract varies widely — diabetes-heavy panels came out slightly ahead, mental-health-heavy panels lost the most ground, and vascular-disease categories lost some of their biggest coefficient weights entirely.
What V28 is — and what it replaces
CMS uses Hierarchical Condition Category (HCC) models to set the capitation that Medicare Advantage plans receive per enrollee per month. Each HCC is a clinical category tied to a RAF (risk adjustment factor) coefficient; higher-RAF enrollees generate higher capitation. V24 was the model in use from payment year 2020 through the beginning of the V28 phase-in. V28 was finalized in the CMS risk adjustment program and introduced via the 2024 Rate Announcement.
The reason CMS updated the model is clinical accuracy. V24 was built on diagnosis patterns from the 2010s, and HCC research published by the HHS Office of Inspector General identified a handful of categories that were producing RAF inflation disproportionate to clinical severity — most notably low-specificity depression diagnoses and mild atherosclerosis codes. V28 tightened those categories.
Structurally, V28 also rebuilt the HCC hierarchy rules that decide which category wins when two codes could both map. In V24 a patient with both uncomplicated diabetes (E11.9) and diabetes with CKD (E11.22) would roll up to a single "diabetes with complications" HCC, and the uncomplicated code was effectively ignored for RAF. V28 kept that rollup but split complications into finer buckets, so the specific assessment statement in the chart now matters more — an "E11.9" chart that the documentation actually supports as E11.22 leaks RAF at a higher rate than it did under V24. The coder-facing implication is that chart review effort shifts from "find-the-diagnosis" to "upgrade-the-specificity," which is a different muscle and requires retraining the query writers.
CMS's own rationale for V28, stated in the 2024 Advance Notice and carried through the 2025 Rate Announcement, was that V24's category set had drifted from the clinical profile of the 2020s Medicare Advantage population. New drug therapies for diabetes, the shift in mental health diagnostic coding after DSM-5-TR, and the aging of the MA-enrolled population changed which conditions drive care utilization and which do not. V28 calibrated against those newer patterns. The CMS risk adjustment data repository publishes the full model software ZIP and the underlying coefficient tables for anyone who wants to audit the math directly.
Coders looking for a plain-English walkthrough of the category-by-category changes can read the V28 full implementation guide or the more condensed "what changed" summary. For a historical model-by-model comparison, the V24 vs V28 deep-dive is the most-cited reference in the HCC Buddy library.
The V24/V28 blend schedule (2024–2027)
CMS introduced V28 as a three-year blend to smooth revenue impact on MA plans. Each payment year's RAF score is computed twice (once under V24, once under V28) and the results are weighted:
| Payment year | V24 weight | V28 weight | Status |
|---|---|---|---|
| 2024 | 67% | 33% | Historical |
| 2025 | 33% | 67% | Historical |
| 2026 | 0% | 100% | Current |
| 2027+ | 0% | 100% | Projected |
Coders auditing claims for a specific payment year should apply the weighted model in effect for that year. The RAF score calculator can toggle between V24 and V28 for the same diagnosis list, which is the fastest way to see how a mixed panel shifts between payment years. The V28 transition guide walks through the practical implications of the 2026 switch for coding ops managers.
Category families that gained or lost ground
Gained specificity (RAF-positive)
- Diabetes with complications (E11.22, E11.40, E11.65)
- Heart failure with reduced ejection fraction
- Chronic kidney disease stages 4–5
- Active substance use disorders
- Major depressive disorder, severe
Lost HCC weight (RAF-negative)
- Intermittent claudication without ischemia
- Angina pectoris without CAD
- Mild/unspecified depression (formerly HCC 59)
- Substance use in remission
- Protein-calorie malnutrition, unspecified
Coders reviewing charts for patients with the "lost weight" profile should reset expectations — extra documentation on those diagnoses no longer produces revenue. Chart review effort should shift toward the "gained specificity" list, where a single assessment statement can upgrade an unspecified code to a specified one and materially affect the 2026 RAF.
The 2026 HCC list — chronic conditions by category
The 2026 V28 payment HCC list is organized by clinical body system. The categories below are the highest-frequency HCCs across the Medicare Advantage population — the ones most MA plans see on 60%+ of risk-adjustable enrollees. A full category-to-category mapping against specific ICD-10 codes lives on the ICD-10 to HCC mapping hub, and every individual code can be looked up via the HCC Buddy encoder.
Endocrine (HCC 35–38)
Diabetes with and without complications. V28 split the former single diabetes HCC into three tiers. See the diabetes HCC coding guide for the full complication hierarchy.
Cardiovascular (HCC 221–226)
Heart failure (with and without reduced EF), acute and chronic ischemic heart disease, specified arrhythmias. Start with the heart failure HCC guide and the atrial fibrillation guide.
Renal (HCC 326–329)
CKD stages 3–5, ESRD, dialysis status. See the CKD HCC coding guide.
Respiratory (HCC 280–283)
COPD, asthma with specified severity, interstitial lung disease. See the COPD HCC coding guide.
Mental & Behavioral (HCC 155–159)
Major depressive disorder (severe), schizophrenia, bipolar disorder, active substance use disorders. See the depression HCC coding guide.
Neurological (HCC 103–105)
Alzheimer's, vascular dementia, Parkinson's, multiple sclerosis. See the dementia HCC coding guide.
Metabolic/Obesity (HCC 48)
Morbid obesity (BMI ≥ 40). See the obesity / BMI HCC coding guide.
The top 10 HCC codes across the MA population and the top 10 miscoded HCCs reports are the quickest way to prioritize chart review capacity for 2026. Both lists are HCC Buddy-maintained and updated against the current V28 coefficient set.
How the 2026 coefficient set changes RAF math
V28 RAF is still the sum of demographic factors plus HCC coefficients plus interaction terms, but the coefficients themselves moved. A community-dwelling non-dual 70-year-old female with diabetes with CKD (E11.22) who carried a ~0.302 diabetes RAF under V24 now carries ~0.365 under V28 — a net gain. The same patient's intermittent claudication code (I73.9) that carried ~0.288 under V24 now carries 0.000 — a net loss. Average contract-level RAF is down ~3.2% before any chart-review optimization.
Coders preparing payment-year 2026 projections should run the RAF calculator on representative panels side-by-side under V24 and V28 to identify which patients slipped below the capitation break-even line. The RAF score calculation guide walks through the demographic-plus-condition arithmetic that drives the final payment.
The ICD-10 combination codes RAF guide covers the specific code-pair rules — certain diagnoses combine to a higher-specificity HCC rather than stacking — and is the most common source of missed RAF lift during chart review.
MEAT documentation under V28
V28 did not change the MEAT documentation standard — every HCC submitted still requires Monitor, Evaluate, Assess, or Treat evidence in a face-to-face encounter during the payment year. What V28 changed is which conditions are worth the documentation effort. Provider education decks that previously emphasized vascular disease and mild depression should be reweighted toward diabetes specificity, heart failure severity, and CKD stage. See the MEAT criteria hub for the framework, the provider query templates for AHIMA-compliant prompts, and the RADV audit prep guide for how V28 documentation stands up under audit.
The parallel 2023 RADV final rule removed the fee-for-service adjuster and allowed CMS to extrapolate audit findings across contracts, which means unsupported V28 HCCs now produce larger payment recoveries than unsupported V24 HCCs would have under the prior rule. Compliance teams treating V28 as "just a coefficient change" are misreading the risk.
Practically, the MEAT bar under V28 is higher for the conditions that still pay. A diabetes encounter that previously cleared audit with "DM, on metformin, stable" now needs to name the complication (neuropathy, CKD stage, retinopathy) to land on a V28-mapped code like E11.22 — and the MEAT narrative has to support that specificity. Heart-failure notes that said "CHF, continue Lasix" need to document systolic vs diastolic, acute vs chronic, and the clinical monitoring that justified the encounter. Coders who learned V24-era shortcuts — accepting a "history of" phrase as MEAT, or letting ambiguous laterality ride — will see those charts flagged on the first RADV pull under the 2023 rule. Retraining the chart-review rubric is not optional; it is the difference between keeping and refunding V28 dollars.
The shift also changes what provider-education sessions should emphasize. Under V24, "code to the highest specificity" worked as a generic mantra because almost every chronic condition carried some RAF weight. Under V28, specificity only matters where it crosses a mapping threshold — E11.9 without a complication stays unmapped no matter how well-documented it is, while E11.22 with proper CKD staging moves from nothing to HCC 37. Education content should lead with the map, not with the alphabet, and coder-QA dashboards should surface unmapped diabetes and heart-failure encounters as rework candidates, not as pass-through clean claims. Plans that rebuilt their provider-facing cheat sheets the week of CY2024 are seeing measurable capture lift; plans still running V24-era decks into 2026 are leaving coefficient dollars on the floor every encounter. The same logic applies to retrospective chart review: V24-trained reviewers will flag dozens of "missed" HCCs per chart that no longer map, burning reviewer hours on zero-yield rework. Re-scoping the review queue to V28-mapped categories is a one-time project that pays back in the first quarter.
What coders should actually do for 100% V28
- Re-audit the current-year problem list against the V28 map. Every patient's active problem list should be walked against the ICD-10 → HCC mapping tool to identify conditions that lost RAF weight (stop chasing) versus gained specificity (escalate to the provider).
- Download the updated cheat sheet. The HCC Buddy cheat sheet now leads with the V28 decision tree rather than V24. Print one per workstation.
- Install the Chrome extension. The HCC Buddy extension surfaces V28 HCC categories and RAF weights inline inside the EHR, so coders do not have to switch tabs during chart review.
- Re-train providers on the new priority conditions. Use the payer guidelines library to pull your payer's specific V28 documentation guidance (Humana, Aetna, UnitedHealthcare, and CMS all published provider-facing V28 briefs in 2024–2025).
Frequently Asked Questions
Related coding tools
ICD-10-CM Encoder
Look up any code and see V28 HCC + RAF inline.
ICD-10 to HCC mapping
The full 72K-code mapping hub with V28 categories.
MEAT criteria
The documentation standard behind every V28 HCC.
RAF Score Calculator
Toggle V24 vs V28 on any diagnosis list.
Payer Guidelines Library
Search CMS, Humana, Aetna V28 documentation.
HCC coding cheat sheet
Free V28 decision tree PDF.
Built by a Certified Risk Coder. Sourced from CMS, OIG, and the Federal Register.
Zero PHI · 2026 CMS V28 current · Reviewed against the April 2025 CMS Rate Announcement