Quick Answer: The CMS-HCC Model V28 is fully operative as of January 1, 2026. This version 28 risk adjustment model replaces version 24, cuts valid ICD-10-CM diagnosis codes from 9,797 to 7,770, expands hierarchical condition categories (HCCs) from 86 to 115, and lowers average Medicare Advantage risk scores by a projected 3.12 percent. [1] CMS finalized the CY2027 Rate Announcement on April 6, 2026 with a 2.48 percent payment increase, but did not finalize the proposed V28 recalibration after a skin substitute cost anomaly distorted the data. [7] Plans and providers still running add-only coding face reimbursement shortfalls and audit exposure in an active enforcement environment.
Key Takeaways
- The V28 risk adjustment model is fully operative as of payment year 2026, governing 100 percent of MA risk adjustment scores.
- Valid diagnosis codes fell by a net 2,027: many conditions that drove risk adjustment factor (RAF) scores under V24 no longer count.
- Severity of illness now outweighs the raw number of diagnoses, reversing the incentive behind add-only chart review.
- CMS finalized the CY2027 Rate Announcement with a 2.48 percent payment increase but did not finalize the proposed V28 recalibration; the existing V28 calibration continues into CY2027.
- CMS finalized the exclusion of unlinked chart review record diagnoses and audio-only encounter diagnoses from risk score calculation for CY2027.
- Add-only retrospective programs face payment cuts and active DOJ enforcement; two-way coding (add and remove) is the defensible standard.
- AI-driven platforms with explainable, MEAT-based evidence trails are the most defensible path forward for healthcare organizations under V28.
What Is the CMS-HCC Model V28?
The CMS-HCC Model V28 is the current Hierarchical Condition Category risk adjustment model that the Centers for Medicare & Medicaid Services (CMS) uses to calculate risk adjustment factor (RAF) scores for Medicare Advantage members, calibrated on more recent fee-for-service cost and diagnosis data.
V28 replaces V24, the risk adjustment model that governed Medicare Advantage for the prior decade. Where V24 mapped patient diagnoses to 86 HCC categories using 9,797 ICD-10-CM codes version 28 uses 115 hierarchical condition categories but applies only 7,770 diagnosis codes, a net reduction of more than 2,000 valid codes. [1] That difference changes which conditions generate risk scores, how much each is worth, and which coding practices hold up under audit.
The shift reflects what CMS aims to do: align the risk adjustment model more closely with actual Medicare fee-for-service spending using current data. The signal from CMS is consistent across every recent rulemaking. Pay for documented patient care, not coding volume. For providers and risk-bearing organizations, that means the new model rewards clinical precision over diagnosis count, and it penalizes records that cannot prove a condition is current and active.
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When Did CMS Implement V28? The V24 to V28 Transition Timeline
CMS finalized the V28 risk adjustment model in the 2024 Rate Announcement and phased it in over three payment years, reaching 100 percent implementation on January 1, 2026. Both V24 and V28 are CMS-HCC risk models, but the transition between them was deliberately gradual so organizations could adjust budgets and coding practices.
The phase-in blended the two risk models by payment year:
Payment year | V28 weight | V24 weight |
PY 2024 | 33% | 67% |
PY 2025 | 67% | 33% |
PY 2026 | 100% | 0% |
Source: CMS 2024 Rate Announcement [1]
That blend is what made the rollout feel manageable in 2024 and sharp in 2026. A plan that leaned on V24-era coding could still collect most of its expected risk scores in payment year 2024, when two-thirds of the calculation still ran on the old model. By 2026, that cushion is gone. The full weight of the new model now applies to every MA member, so any gap between V24 habits and version 28 requirements shows up at full size in the risk adjustment scores plans report.
The practical lesson here is that the model change and the enforcement change arrived together. The same year V28 hit 100 percent, RADV audits resumed at scale and the CY2027 cycle finalized new limits on unlinked chart review. Organizations that treated it as a future problem are now managing it as a present one.
What Changed from V24 to V28
The V24 to V28 shift comes down to four areas: code volume, HCC category expansion, the constraining process, and how the risk adjustment model weights clinical seriousness. Each one changes how diagnoses translate into risk scores, and each one raises the bar for the record.
Code Volume and HCC Categories
The total number of valid ICD-10-CM diagnostic codes dropped from 9,797 in V24 to 7,770 in V28, a net reduction of 2,027 codes, reflecting 2,236 codes removed and 209 added. [1] HCC categories expanded from 86 to 115. The model now covers more clinical conditions at a higher level of specificity, while excluding a significant share of diagnostic codes that previously contributed to risk scores. Healthcare organizations still running V24-era coding logic are almost certainly submitting diagnosis codes that no longer count.
CMS-HCC mapping | V24 | V28 |
HCC categories | 86 | 115 |
Valid ICD-10-CM codes | 9,797 | 7,770 |
Net code change | baseline | -2,027 (2,236 removed, 209 added) |
Projected avg. RAF impact | baseline | -3.12% |
Source: CMS 2024 Rate Announcement [1]
The Constraining Process
V28 introduces constraining, where related HCCs are assigned the same coefficient value to prevent double-counting clinically related conditions. Under V24, a patient with a chronic condition and a related complication generated separate, additive HCC contributions. Under V28, both conditions map to the same coefficient. [1] In fact, every form of that disease now carries the same coefficient value, regardless of complication status. [1] The result is a lower RAF score for patients with multiple chronic conditions, with no change in their actual health status.
Severity Over Volume
V28 prioritizes severity of illness over the number of diagnoses. A patient with two serious conditions can generate a higher risk score than a patient with five mild ones. This reverses the incentive that drove add-only retrospective chart mining for a decade, and it rewards records that reflect true clinical complexity rather than diagnosis count.
Specific Category Changes
Among the key changes by category, depression coding tightened sharply: depression codes were reduced by more than half, so only moderate-to-severe active major depression generates an HCC risk score. Mild, unspecified, or in-remission depression no longer counts. [1] Morbid obesity coding drew direct enforcement scrutiny in the Aetna case, where $11.5 million of the $117.7 million settlement resolved allegations of false morbid obesity diagnoses for PY 2018 through 2023. [3] Protein-calorie malnutrition is no longer a valid HCC code under V28. Each of these code changes pushes the same point: the diagnosis has to be real, current, and documented.
How HCC V28 Mapping Works
HCC V28 mapping is the process of translating ICD-10-CM diagnosis codes into hierarchical condition categories, then applying hierarchies so that only the most clinically significant category in a related family counts toward the risk score. Getting that mapping right is the foundation of an accurate, defensible RAF score under the version 28 risk adjustment model.
The chain runs in three steps. A clinician documents a condition. A coder assigns the ICD-10-CM diagnosis code that the record supports. The model maps that diagnosis code to one of its 115 hierarchical condition categories, if a valid mapping exists. Many ICD-10-CM codes map to a single HCC, and many codes (the 2,236 removed in V28) now map to nothing at all for risk adjustment purposes.
What Is Hierarchy in HCC Mapping?
Hierarchy in HCC mapping means that within a family of related conditions, the most severe category supersedes the less severe ones, so a patient is credited once for the highest-acuity condition documented, not for every step below it. This is the “hierarchical” part of HCC mapping, and it predates V28. What changed is how tightly the model draws those families.
A clean example is any chronic disease with complications. If the record supports the complicated form, that higher HCC trumps the uncomplicated category, and only the higher one counts. The patient is not credited twice for the same disease. Constraining, new under V28, goes a step further by forcing some related HCCs to share an identical coefficient, which flattens the extra risk a plan could earn from documenting linked conditions separately.
For risk adjustment coding teams and providers, the takeaway from HCC V28 mapping is concrete. Re-verify your crosswalks against the current V28 definitions every cycle. A crosswalk built on V24 logic will keep routing diagnostic codes to categories that no longer carry HCC risk weight, inflating expected scores the risk adjustment model will never pay. Accurate mapping is not a one-time setup; it is an ongoing control that protects both RAF scores and the audit trail.
How V28 Lowers RAF Scores for Most Members
RAF scores are lower under V28 for most Medicare Advantage patients, with a CMS-projected 3.12 percent average decline. [1] Members with several related chronic conditions can see a steeper drop, because constraining removes the duplicative credit those conditions earned under V24. A RAF score blends demographic factors such as age and sex with diagnosis-driven HCCs, and V28 reworked the diagnosis side. A lower score does not mean a member’s health status improved; it means the risk adjustment model now credits fewer of the conditions in the record.
That is why defensible documentation now decides reimbursement. A code that cannot be tied to a current patient encounter with clinical evidence is no longer a quiet revenue adjustment. It is an audit flag. V28 has tightened the link between what a plan documents and what it gets paid, and it has done so in the same year RADV audits resumed at scale. If you want a framework for protecting risk adjustment factor scores without crossing into optimization, see how to build defensible RAF scores.
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Expert Perspective
“V28 isn’t a technical update to a model. It’s CMS signaling that documentation should reflect actual patient complexity, not a list of codes. If you can’t link a diagnosis to a current encounter with MEAT-based evidence (Management, Evaluation, Assessment, and Treatment), you shouldn’t be submitting it.”
Wynda Clayton, MS, RHIT, CRC, Director of Risk Adjustment Coding & Compliance, RAAPID | Former CMS RADV Auditor
How V28 Reshapes Coding for Chronic Conditions
The version 28 risk adjustment model hits chronic conditions hardest, because constraining and the new weighting together strip out the additive credit that high-prevalence conditions earned under V24. For most plans, chronic conditions are where the projected RAF decline lives.
Diabetes is the clearest example. Under V24, complications often added separate HCC value. Under V28, all its forms share one coefficient, so the documented presence of complications no longer multiplies the risk score the way it once did. [1] Similar logic applies across the chronic disease categories that dominate MA panels. Chronic kidney disease, COPD, heart failure, and vascular disease all still matter clinically and still shape a member’s health status, and they belong in the record, but the model now expects each one documented with stage and status rather than simply listed.
Vascular disease deserves a closer look, because it is one of the categories where history-of conditions get miscoded most often. A resolved embolism or a prior vascular event recorded as current vascular disease is exactly the kind of unsupported diagnosis that lowers a plan’s audit standing while adding risk it cannot defend.
For organizations managing large populations with multiple chronic conditions, the practical takeaway is direct. The path to accurate risk scores runs through better records of the conditions clinicians already treat, not through finding more diagnoses to add. Two-way review matters here too: a chronic condition coded as active when the record shows it resolved is precisely what a RADV auditor will pull. Done well, chronic condition coding under V28 produces lower scores that are fully defensible, which is a stronger position than higher scores that collapse under review.
What the OIG Audit Series Reveals About High-Risk Diagnoses
The OIG’s March 2026 compliance audit (Report A-07-22-01207) shows what V28-era audits actually find: a 91 percent error rate on high-risk diagnoses. OIG reviewed 271 sampled enrollee-years across nine high-risk diagnosis categories and found 247 with unsupported diagnosis codes. [5]
Two categories stood out. Acute stroke and acute myocardial infarction each carried a 100 percent error rate in the sample, 30 of 30 apiece. [5] The most common error pattern across all nine categories was history-of conditions coded as active diagnoses: a past stroke coded as acute stroke, resolved cancer coded as active malignancy, a prior embolism coded as current vascular disease.
That is exactly the distinction V28 makes critical. The same acute, high-cost conditions that warrant higher reimbursement when genuinely documented are the ones most likely to attract RADV scrutiny when the record does not hold up. The OIG findings are not an outlier. Across this audit series, high-risk diagnosis groups have repeatedly shown error rates in the 80 to 95 percent range, which tells risk-bearing organizations the problem is systemic, not isolated to a single plan.
RADV Audits Are Active Again
The Centers for Medicare & Medicaid Services confirmed in its January 2026 memorandum that RADV audits have resumed on an accelerated schedule, covering PYs 2018 through 2024. [4] CMS estimates roughly $17 billion in annual MA overpayments from unsupported diagnosis data, and it intends to clear outstanding audits on an expedited timeline. [4]
Key RADV facts (CMS, January 2026):
- Audits cover PYs 2018 through 2024 on an expedited timeframe
- Variable sample sizes: 35 to 200 enrollees per contract depending on size
- Medical record submission window: five months
- New audits initiated roughly every three months
- Maximum two medical records per audited HCC
- All overpayment coding decisions made by human certified medical coders
- AI used as a coder support tool only, not the decision-maker
With audits reaching every eligible contract across seven consecutive years, the question is no longer whether an organization gets audited. It is how the record holds up when it does. For the full timeline, sample-size rules, and record window, see our RADV audits in 2026 breakdown.
The Essential Guide to CMS-HCC Model V28
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How MEAT Criteria Anchors Defensible V28 Coding
MEAT criteria (Management, Evaluation, Assessment, and Treatment) is the documentation convention used to validate HCC diagnoses, where any one of the four elements, tied to a current face-to-face patient encounter, supports a coded condition.
Under V24, the broader code set let some diagnoses persist in annual submissions without airtight evidence. V28 closes that window. Fewer valid codes plus a constraining process that strips duplicative credit mean every code submitted has to earn its place in the record.
The OIG audit makes this operational. In all nine high-risk categories reviewed, the medical review contractor asked one question on evaluation: did the record document the coded condition as current, active, and appropriately treated, rather than a historical reference? [5] Plans and providers whose records cannot clear that bar carry audit exposure on every submission cycle. MEAT is an industry convention rather than a CMS-named standard, but it maps cleanly onto what auditors look for under evaluation, which is why it remains the practical foundation of defensible coding under the version 28 model.
How V28 Affects Dementia and Cognitive Impairment Coding
Dementia remains a high-RAF condition under V28, and the new model expands those categories to capture finer clinical distinctions, but it requires more specific documentation to qualify. [1] For MA organizations with older, higher-acuity panels, dementia coding is one of the highest-value and highest-risk areas in the entire risk adjustment model.
The clinical reality is that dementia is estimated to be underdiagnosed in roughly 60 percent of cases by current standards. [6] That gap creates two problems at once: missed clinical recognition that affects patient care, and missed coding that affects risk scores. When dementia is finally documented, it has to be documented well, because the model now expects the record to support the exact category coded.
Mild cognitive impairment (MCI) sits right at the classification threshold where precision decides whether a patient’s condition qualifies as a valid HCC. It is not the same as dementia, and the record has to make that distinction clear. Under V28, the bar for coding it is higher than it was under V24. A note that mentions “memory problems” or carries a historical dementia reference will not survive an audit. The chart has to show current evaluation, current management, and the severity level being coded.
Practical dementia coding guidance under V28 comes down to three habits:
- Document the type and stage. Distinguish MCI from early, moderate, or advanced dementia, and code to the level the record actually supports.
- Tie the diagnosis to a current encounter. A dementia or MCI diagnosis needs MEAT-based evidence from a current visit, not a problem-list carryover.
- Capture the functional picture. Charting that connects the condition to function, treatment, and care planning is far more defensible than a standalone diagnosis line.
Done right, dementia coding under V28 captures real patient complexity and survives scrutiny. Run as add-only volume, it becomes one more unsupported diagnosis in an audit sample.
What V28 Means for Providers and Provider Groups
The new model shifts real work to providers, because the documentation that supports a defensible code can only be created at the point of care, where the clinician sees the patient. Risk adjustment is no longer something a retrospective team can fully repair after the fact.
For providers, the change is concrete. The conditions a clinician evaluates and treats have to be documented with enough specificity that the diagnosis maps cleanly to a V28 HCC. That means recording the severity of the condition, its status (active versus historical), and the clinical reasoning behind the evaluation and assessment. Provider groups under value-based contracts depend on this discipline across every clinician, not just the coding team, because accurate scores now ride on what happens during patient encounters.
The healthiest programs treat this as clinical support, not pressure. Providers respond to guidance that fits their workflow and respects their clinical judgment, not to coercion or revenue targets. That distinction matters under V28, because the same enforcement actions that target add-only chart review also scrutinize programs that look like they push providers to code for reimbursement rather than for care. Decision support at the point of care, surfacing the clinical evidence and letting the clinician make the call, is both the compliant approach and the one providers actually adopt.
Provider organizations and health plans that share data also share an advantage. When documentation guidance reaches the clinician during the visit, the conditions that drive accurate scores get captured the first time, and downstream risk adjustment teams spend less effort chasing records after the fact. Health plans own the risk score and the audit exposure, while provider organizations own the clinical record that has to support it. The provider organizations that perform best under V28 treat these as one shared problem, because a risk score is only as defensible as the chart behind it.
How Health Plans Should Adapt to V28
Healthcare organizations of every size, from regional Medicare Advantage plans to large provider groups, can navigate the version 28 transition along the same compliance path: document what is real, link it to evidence, review in both directions, and make sure your tools can show their work.
- Audit current coding against V28 mapping. Identify which ICD-10-CM codes in your workflow are no longer valid. The removal of 2,027 codes means existing workflows almost certainly carry obsolete codes that generate no score and may generate audit flags.
- Shift from volume to clinical precision. Document each diagnosis precisely enough to survive scrutiny. Invest in clinical documentation improvement (CDI) at the point of care, not retrospective code addition.
- Run two-way retrospective reviews. The Aetna action establishes that programs which add codes but never remove unsupported ones are a legal liability. Every review should surface both missed diagnoses and unsupported ones. See RAAPID’s retrospective risk adjustment solution.
- Flag high-risk categories proactively. Apply targeted validation to OIG focus areas before submission: acute stroke, acute MI, embolism, sepsis, vascular disease, and cancers where history-of conditions may have been coded as active.
- Use AI with an auditable evidence trail. CMS plans to use AI as a coder support tool in audits. [4] Plans whose tools cannot produce an evidence trail are at a structural disadvantage. RAAPID’s Clinical AI Platform uses Neuro-Symbolic AI, combining large language models with clinical knowledge graphs, to validate every HCC against MEAT-based evidence pulled directly from the note. Charts take 8 to 12 minutes to review.
What the CY2027 Final Rate Announcement Means for V28
The Centers for Medicare & Medicaid Services finalized the CY2027 Rate Announcement on April 6, 2026 with a 2.48 percent net payment increase, and it did not finalize the proposed V28 recalibration after a skin substitute cost anomaly distorted the underlying data. [7] The practical result: the existing V28 calibration, the risk adjustment model finalized in the 2024 Rate Announcement, continues into CY2027 without the deeper coefficient cuts the Advance Notice had floated.
This is the recalibration freeze plans should plan around. The steep condition-level reductions proposed in the February 2026 Advance Notice were not adopted for CY2027. [2] CMS deferred them rather than locking in coefficients built on anomalous cost data. For risk-bearing organizations, that removes one near-term shock, but it does not change the trajectory. The new model still favors clinical seriousness and specificity, and the policy direction still moves away from add-only volume.
Two policy changes from the cycle were finalized and do take effect:
- Unlinked chart review records excluded. CMS finalized the exclusion of diagnosis information from unlinked chart review records, meaning diagnoses not tied to a specific beneficiary encounter, from risk score calculation for CY2027. This is a direct regulatory limit on the add-only chart mining model. [7]
- Audio-only encounters excluded. CMS finalized the exclusion of audio-only encounters as a source of risk adjustment diagnoses for CY2027. [7]
For reference, here is what the Advance Notice had proposed before the recalibration was set aside. Treat it as deferred context, not current policy.
Proposed CY2027 Coefficient Changes (Not Finalized)
Condition / HCC | Proposed coefficient change |
CKD Stage 3A | -50.4% |
Drug Use Disorder (moderate/severe) | -24.3% |
Morbid Obesity | -19.4% |
COPD | -18.8% |
Rheumatoid Arthritis | -17.3% |
Major Depression | -13.7% |
Heart Failure | -10.8% |
Diabetes | -6.6% |
Bladder/Colorectal/Other Cancers (HCC 22) | +12.1% |
Septicemia/Sepsis/SIRS/Shock (HCC 2) | +15.6% |
Source: CMS 2027 Advance Notice, February 2026 (proposed, not finalized in the April 2026 Rate Announcement) [2]
The strategic takeaway holds even with the freeze. The direction CMS set with V28 has not reversed. Unlinked retrospective volume is structurally ending, and the path forward runs through encounter-based documentation, prospective decision support at the point of care, and coding programs that remove unsupported diagnoses as readily as they add missed ones.
The Role of AI in V28 Compliance
AI-driven platforms are now a practical necessity for healthcare compliance under V28, because the volume of code changes, the precision required in ICD-10-CM to HCC mapping, and the dual obligation to add and remove diagnosis codes exceed what manual workflows handle reliably at scale.
The most defensible AI-driven platforms for accurate risk adjustment under V28 do four things. They analyze structured and unstructured data to surface conditions that still qualify under the model’s more specific requirements. They analyze and cross-walk V24 codes to V28, flagging diagnostic codes that were removed or reclassified. They give providers documentation guidance during the patient encounter, not only after it. And they generate evidence trails that link every suggested HCC to the specific clinical language in the medical record.
The unstructured data point matters more under V28 than it did under V24. The two things the model now rewards, the severity of a condition and whether it is currently active, usually live in the clinical narrative, not in the structured problem list. A platform that only reads structured data misses the detail that makes a code defensible, and it misses the health status nuance that separates a current condition from a resolved one.
CMS’s own RADV plan calls for AI as a coder support tool, with human certified coders retaining all authority over overpayment determinations. [4] That is the same human-in-the-loop model RAAPID uses: Neuro-Symbolic AI surfaces the evidence and validates the HCC, and the clinician or coder makes the final call. RAAPID’s Clinical AI Platform reaches 92 percent out-of-the-box accuracy, rising to over 98 percent after human-in-the-loop QA review, with a 60 to 80 percent productivity gain for risk adjustment coding teams.* Generic NLP can spot that the word “diabetes” appears in a chart. What it cannot reliably do is separate a current, actively managed diabetic condition with documented complications from a historical mention of resolved glycemic issues. V28’s logic demands that distinction at scale, and it demands an evidence trail that holds up when an auditor asks why a code was submitted.
What Risk Adjustment Leaders Are Asking About V28
- Is the V28 risk adjustment model fully in effect for 2026?
- How many diagnosis codes did V28 remove compared to V24?
- Did the CY2027 rate announcement change the V28 risk adjustment model?
- Why are RAF scores lower under V28 for the same patient?
- What high-risk diagnoses are RADV auditors flagging most?
- How does V28 change dementia and cognitive impairment coding?
- How do we make our V28 coding defensible before an audit?
Conclusion
The V28 risk adjustment model has changed what defensible risk adjustment looks like. Fewer valid codes. A weighting structure built on clinical seriousness. A constraining process that eliminates duplicate credit. And an enforcement environment with active RADV audits, OIG reviews finding 91 percent error rates on high-risk diagnoses, and DOJ settlements aimed squarely at add-only programs.
The CY2027 freeze does not change that direction. CMS finalized a 2.48 percent increase and deferred its proposed recalibration, but it also finalized the exclusion of unlinked chart review and audio-only diagnoses. The message is the same one V28 delivered: prove the codes you submit.
This is not a documentation problem alone. It is a clinical accountability problem. The organizations and providers that navigate V28 link every code to encounter-grounded evidence, run two-way reviews that capture missed complexity and remove unsupported codes, and use AI that can show its work to an auditor.
Risk adjustment has shifted from a revenue function to a clinical, compliance, and enterprise AI discipline. RAAPID’s Clinical AI Platform was built for this environment: explainable, evidence-based, two-way, and audit-ready. To see how RAAPID supports Medicare Advantage plans and healthcare providers under V28, request a demo.
Internal RAAPID benchmark. 92 percent out-of-the-box accuracy is an independently validated proof-of-concept figure; 98 percent-plus reflects final quality accuracy after human-in-the-loop QA review.*
Frequently Asked Questions About CMS-HCC Model V28
Yes. The risk adjustment model became fully operative for payment year 2026, so 100 percent of Medicare Advantage risk scores are now calculated under V28. The phased rollout (33 percent in 2024, 67 percent in 2025) is complete. [1] Voice answer: CMS-HCC Model V28 took full effect on January 1, 2026. All MA risk adjustment scores are now calculated under V28.
CMS finalized V28 in the 2024 Rate Announcement and phased it in over three payment years: 33 percent V28 in 2024, 67 percent in 2025, and 100 percent in 2026. The transition from V24 to version 28 ran three years and completed on January 1, 2026. [1]
The V28 model uses 115 hierarchical condition categories and 7,770 valid ICD-10-CM diagnosis codes. V24 used 86 categories and 9,797 codes, so V28 added 29 categories while cutting a net 2,027 diagnosis codes. [1] Voice answer: V28 has 115 HCC categories and 7,770 valid ICD-10-CM codes.
Hierarchy in HCC mapping means the most severe condition in a related family supersedes the less severe ones, so a patient is credited once for the highest-acuity category documented. V28 also adds constraining, which forces some related HCCs to share the same coefficient value.
No. CMS finalized the CY2027 Rate Announcement on April 6, 2026 with a 2.48 percent payment increase but did not finalize the proposed V28 recalibration after a skin substitute cost anomaly. The existing V28 calibration continues into CY2027. [7]
CMS expects programs to both add missed diagnoses and remove unsupported ones. The Aetna/CVS $117.7 million DOJ settlement in March 2026 penalized an add-only program that submitted codes without deleting unsupported diagnoses found in the same review. [3] Two-way coding is the defensible standard under V28.
Yes. CMS’s January 2026 memo confirmed audits covering PYs 2018 through 2024, with sample sizes of 35 to 200 enrollees per contract, a five-month medical record submission window, and new audits launched roughly every three months. [4]
Based on OIG’s March 2026 audit (A-07-22-01207), the highest-risk categories include acute stroke, acute myocardial infarction, embolism, lung cancer, breast cancer, colon cancer, prostate cancer, sepsis, and pressure ulcer. Acute stroke and acute MI showed 100 percent error rates in the sample. [5]
CMS finalized the exclusion of diagnoses from unlinked chart review records and from audio-only encounters from risk score calculation for CY2027. Both limit the add-only chart mining model and reinforce encounter-linked documentation. [7]
MEAT criteria (Management, Evaluation, Assessment, and Treatment) is the documentation convention used to validate HCC diagnoses. Each submitted diagnosis should be supported by at least one of these elements in the record, tied to a current face-to-face patient encounter, not a historical reference.
V28 expands high-RAF dementia HCC categories but requires more specific documentation to qualify. Mild cognitive impairment records must reflect the exact level coded, supported by MEAT-based evidence. Dementia is underdiagnosed in roughly 60 percent of cases, creating documentation risk alongside missed recognition. [6]
Providers should document each condition’s severity and status (active versus historical), tie it to a current encounter, and capture the clinical reasoning. V28 rewards specificity, so a condition recorded with clinical detail is far more defensible than a problem-list carryover.
Source
[1] CMS. Announcement of Calendar Year (CY) 2024 Medicare Advantage Capitation Rates and Part C and Part D Payment Policies. cms.gov/files/document/2024-announcement-pdf
[2] CMS. 2027 Advance Notice for Medicare Advantage Capitation Rates and Part C and Part D Payment Policies (February 2026). cms.gov/files/document/2027-advance-notice.pdf
[3] U.S. Department of Justice. Aetna Agrees to Pay $117.7 Million to Resolve False Claims Act Allegations (March 11, 2026). justice.gov/opa/pr/aetna-agrees-pay-1177-million-resolve-false-claims-act-allegations
[4] CMS, Center for Program Integrity. Update on the Status of Medicare Advantage Risk Adjustment Data Validation Audits. Memorandum, January 27, 2026. cms.gov/data-research/monitoring-programs/medicare-risk-adjustment-data-validation-program
[5] OIG, HHS. Medicare Advantage Compliance Audit of Specific Diagnosis Codes (Contract H0104). Report A-07-22-01207 (March 2026). oig.hhs.gov
[6] Alzheimer’s Association. 2024 Alzheimer’s Disease Facts and Figures. alz.org
[7] CMS. Announcement of Calendar Year (CY) 2027 Medicare Advantage Capitation Rates and Part C and Part D Payment Policies (April 6, 2026). cms.gov Medicare Advantage Rates & Statistics
About the author
Wynda Clayton, MS, RHIT, CRC
Director of Risk Adjustment Coding & Compliance, RAAPID
Wynda is a recognized leader with over 20 years of experience in risk adjustment, coding, and compliance. A seasoned former CMS RADV auditor and educator, she focuses on improving coding accuracy and maintaining regulatory standards. At RAAPID, Wynda leads AI-driven initiatives that support defensible, value-based care delivery and reimbursement accuracy.
