Revised Risk Adjustment Model Predicts Lower Medicare Advantage Risk Scores

Medicare Advantage (MA) is privately administered healthcare insurance for seniors and persons with disabilities. The program has grown rapidly and now covers over half of Medicare-eligible enrollees.

Federal payments to MA plans are adjusted to account for enrollees’ health status through a risk adjustment system known as the Centers for Medicare and Medicaid Services Hierarchical Condition Categories (CMS-HCC) model.

In a November 2025 Health Affairs’ Forefront article, we described important methodological questions surrounding an MA encounter-based risk adjustment model that CMS had previewed in late 2024 and has long been considered by policymakers and researchers. To further understand potential implications, we developed an MA encounter-based risk adjustment model and determined the impact on risk scores for MA enrollees.