For years, many Medicare Advantage organizations built their coding and documentation workflows around the CMS-HCC V24 model. Teams became familiar with the diagnoses that consistently contributed to risk adjustment, and providers learned which conditions needed to be captured during annual visits. V28 changed much of that.
Rather than making small adjustments, CMS revisited the relationship between diagnosis coding and expected healthcare costs. The updated model removed several payment HCC categories from the previous model, regrouped others, and removed numerous ICD-10 diagnoses that previously influenced Risk Adjustment Factor (RAF) scores.
The result is a meaningfully different coding landscape. A condition that contributed to risk adjustment under V24 may have less or no impact on payment HCCs under V28 unless the documented diagnosis aligns with the current model. Many organizations have experienced changes in RAF scores following the V28 transition, reflecting updates to the underlying mapping methodology rather than changes in patient health alone.
For organizations managing large Medicare Advantage populations, staying current with these changes can be challenging. Many coding teams now incorporate ongoing HCC mapping reviews and retrospective audits through partners such as MedCode to help identify documentation opportunities while maintaining coding accuracy and compliance.
Why CMS Removed ICD-10 Codes From HCC Mapping Under V28
The removal of certain ICD-10 codes was not intended to reduce payments arbitrarily. Instead, CMS redesigned the model to better reflect the conditions that consistently predict future healthcare utilization and costs.
A move toward more accurate risk prediction
Healthcare delivery has changed considerably since earlier HCC models were introduced. Using more recent claims and clinical data, CMS recalibrated the model to strengthen the connection between documented conditions and expected resource needs.
Simply put, the agency sought to align payment more closely with patient complexity using more recent clinical and claims data.
Greater emphasis on clinical detail
Some broader diagnoses may not, on their own, fully reflect the complexity of a patient’s health status for risk adjustment purposes. Under V28, greater value is placed on diagnoses that clearly describe severity, complications, or disease progression.
Reducing variation in coding practices
Over time, some diagnoses became common contributors to RAF scores even though they showed comparatively lower predictive value for future healthcare spending. The updated model places less emphasis on these diagnoses for payment risk adjustment because they were found to be less predictive of future healthcare costs.
Reflecting current clinical classifications
Medical coding standards continue to evolve, and risk adjustment models must evolve with them. V28 aligns more closely with modern ICD-10 classification principles, making documentation specificity a central part of accurate risk capture rather than an optional enhancement.
In practice coding professionals now spend less time identifying historically valuable diagnoses and more time ensuring the documented condition accurately reflects the patient’s clinical status.
ICD-10 Codes Removed From HCC Mapping Under V28
One of the biggest challenges with the V28 transition is that many diagnoses familiar to coding teams still appear in the medical record but no longer contribute to payment HCCs. That doesn’t make these conditions any less important from a clinical standpoint, it simply changes how they affect Medicare Advantage risk adjustment.
In several instances, CMS removed broader or uncomplicated diagnoses while continuing to recognize conditions supported by greater clinical specificity. Because of this, relying on historical coding habits can lead to missed expectations around RAF scores and reimbursement.
The following table includes examples of diagnosis categories that experienced notable mapping changes under V28.
| Diagnosis Category | V28 Change |
| Diabetes without complications | Many previously mapped diagnoses no longer generate payment HCCs. |
| Peripheral vascular disease | Several commonly reported diagnoses were removed from payment mapping. |
| Depression and certain mental health conditions | Some diagnoses lost HCC status and no longer contribute to RAF calculations |
| Stable angina and related cardiovascular diagnoses | Multiple codes that mapped under V24 no longer trigger payment HCCs |
| Mild or unspecified protein-calorie malnutrition | Lower-severity diagnoses were removed from payment mapping |
The exact impact depends on the documented diagnosis and the current CMS-HCC mapping, making code validation an important part of the coding process.
Diabetes Codes Removed or Reclassified
Diabetes is one of the areas where V28 introduced the most noticeable changes.
Under the previous model, uncomplicated diabetes diagnoses frequently contributed to risk adjustment. The updated version places greater emphasis on complications and documented disease manifestations instead of the underlying diagnosis alone.
When clinically documented, complications such as neuropathy, chronic kidney disease, or retinopathy may provide additional detail that supports a more complete representation of the patient’s condition.
Vascular Disease Codes Removed
Peripheral vascular disease has also seen meaningful changes under V28.
Several diagnoses that previously generated HCC value no longer influence payment calculations. While the condition remains clinically significant, coding professionals should avoid assuming that every vascular diagnosis carries the same risk adjustment weight it once did.
Certain Depression and Mental Health Codes
Mental health conditions continue to play an important role in patient care, but not every diagnosis now contributes to an HCC.
Some broader depression diagnoses that previously mapped under V24 were removed in V28. As a result, coding teams may need more detailed provider documentation to support diagnoses that continue to affect risk adjustment.
Angina and Cardiovascular Diagnoses
Stable angina is another category affected by the updated mapping.
V28 places greater emphasis on diagnoses that better predict future healthcare utilization, which changed how certain stable angina diagnoses contribute to payment HCCs.
Documentation describing underlying cardiovascular conditions, when clinically supported, can provide additional context for risk adjustment.
Malnutrition-Related Diagnoses
Protein-calorie malnutrition remains an important condition to identify, but V28 distinguishes more clearly between varying levels of severity.
Lower-severity or less specific diagnoses that previously generated HCC value may no longer do so. Consequently, provider documentation should clearly reflect nutritional status, supporting clinical findings, and the degree of malnutrition whenever appropriate.
Other Low-Specificity or Reclassified Diagnoses
Beyond these high-profile categories, V28 removed or reorganized a number of diagnoses that offered limited predictive value for future healthcare costs.
For coding departments, the takeaway is less about memorizing deleted codes and more about changing the review process. Historical coding practices may need to be revisited as organizations transition to the updated model. Every diagnosis should ideally be evaluated against the current mapping and supported by documentation that accurately reflects the patient’s condition.
Many organizations have responded by updating internal coding references and performing periodic mapping reviews. Teams that routinely validate their coding practices, including those supported by specialized risk adjustment partners like MedCode, are generally better prepared to adapt as CMS continues refining the HCC model.
How Removed ICD-10 Codes Affect Medicare Advantage Organizations
The impact of V28 extends well beyond individual diagnosis codes. Changes in HCC mapping influence financial performance, coding operations, provider education, and quality improvement initiatives across Medicare Advantage organizations.
RAF Score Reduction
One of the first effects many organizations notice is a change in RAF scores.
Patients whose records previously included diagnoses that mapped under V24 may now receive lower risk scores if those same conditions no longer qualify under V28. In many cases, the patient’s health status has not changed, only the payment methodology has.
Understanding that distinction is essential when evaluating year-over-year RAF trends.
Revenue Considerations
Risk adjustment reimbursement is directly tied to documented patient complexity. When formerly qualifying diagnoses lose HCC status, organizations may see changes in reimbursement if documentation and coding do not accurately reflect clinically supported conditions.
This is why many health plans and provider groups have shifted their focus toward documentation quality and coding accuracy.
Documentation Challenges
V28 places greater emphasis on clinically specific documentation than earlier versions of the model.
Providers are encouraged to document clinically supported conditions with sufficient detail to reflect severity, complications, and disease progression whenever applicable. Even small documentation gaps can affect how a diagnosis maps within the HCC model.
Creating consistent documentation habits across multiple specialties remains an ongoing challenge for many organizations.
Greater Need for Provider Education
Coding professionals may understand the mapping changes, but providers are the ones creating the documentation that supports diagnosis reporting.
Regular education sessions, specialty-specific feedback, and practical documentation examples can help clinicians adapt to evolving HCC requirements without disrupting patient care.
Over time, these efforts tend to improve both coding consistency and documentation quality.
Retrospective Review Becomes More Valuable
As mapping rules become more selective, retrospective chart reviews take on a larger role in risk adjustment programs.
Looking back at completed encounters often reveals documented conditions that were not fully translated into coding or opportunities where additional specificity already existed within the medical record.
In addition to identifying missed coding opportunities, many organizations also use retrospective reviews to evaluate documentation trends and support provider education.
Coding Workflows Continue to Evolve
Many coding teams have updated their internal review processes since the introduction of V28.
Legacy code lists and historical assumptions are gradually being replaced with current mapping references, periodic audits, and ongoing education. Some organizations also work with dedicated risk adjustment partners such as MedCode to support coding validation, retrospective reviews, and documentation improvement initiatives as CMS guidance continues to evolve.
Conclusion
The shift from CMS-HCC V24 to V28 has changed more than HCC categories, it has reshaped how ICD-10 diagnoses contribute to Medicare Advantage risk adjustment. Several codes that once influenced RAF scores no longer generate payment HCCs, making it essential for organizations to revisit long-standing coding practices.
Rather than relying on familiar diagnosis patterns, providers and coding teams should focus on accurate documentation, appropriate code selection, and regular reviews of updated HCC mappings. Even small improvements in clinical specificity can help create a more complete representation of patient complexity while supporting accurate and compliant risk adjustment.
As CMS continues refining the HCC model, staying informed and adapting coding workflows will remain an important part of accurate and compliant risk adjustment. Ongoing education, periodic audits, and retrospective reviews can help organizations navigate these changes with greater confidence.
For healthcare organizations looking to strengthen their risk adjustment processes, MedCode combines coding expertise, documentation reviews, and quality-focused solutions to help teams stay aligned with evolving CMS requirements while maintaining accuracy and compliance.
