Final answer:
The CMS-HCC risk adjustment model specifically affects Medicare Part C, also known as Medicare Advantage, by using risk scores to predict healthcare costs for enrollees.
Step-by-step explanation:
The Centers for Medicare & Medicaid Services-Hierarchical Condition Categories (CMS-HCC) risk adjustment model affects Medicare Part C. Medicare Part C, also known as Medicare Advantage (MA), is an alternative to traditional Medicare (Parts A and B) that allows beneficiaries to receive their benefits through private health insurance plans. These plans are given a capitated payment for each enrollee, adjusted based on the CMS-HCC risk scores, which take into account the health status and demographic characteristics of enrollees to predict healthcare costs. The CMS-HCC model does not directly affect Medicare Part A, Part B, or Part D.