The United States Centers for Medicare and Medicaid Services (CMS) recently published Medicare Advantage (Medicare Part C) and Medicare Part D Star Ratings to measure the quality of health and drug services received by beneficiaries. Less than half of MA plans offering prescription drug coverage in 2024 will receive four or more stars, a decrease from 51% of plans in 2023 and 68% of plans in 2022. When weighted by enrollment, roughly 74% of MA Part D enrollees are currently in a contract that will have four or more stars in 2024.
The below table shows the overall star rating distribution for Medicare Advantage Part D contracts for years 2021, 2022, and 2023.
| Overall Rating | 2021 | 2022 | 2023 |
| 5 stars | 21 | 74 | 57 |
| 4.5 stars | 63 | 96 | 67 |
| 4 stars | 110 | 152 | 136 |
| 3.5 stars | 141 | 122 | 116 |
| 3 stars | 61 | 25 | 90 |
| 2.5 stars | 4 | 2 | 37 |
| 2 stars | 0 | 0 | 4 |
CMS notes that the change in distribution of stars is influenced by changes in measure scores “in both positive and negative directions based on contract performance” as well as some changes made to the measures, including re-specifying and transitioning the updated Plan All-Cause Readmissions (Part C) measure and the Tukey outlier deletion. Tukey outlier deletion involves removing outlier contract scores prior to applying mean resampling within the hierarchical clustering algorithm to determine measure-level cut points.
CMS further notes that 36 contracts are highlighted on the Medicare Plan Finder with a high performing icon, indicating that they earned 5 stars. 31 of those are MA-PD contracts, three are 1876 Cost Contracts, and two are PDPs. For 2024, there were 11 contracts that received the high performing icon that did not receive it in 2023.
There were also six contracts identified on the Medicare Plan Finder with a low performing icon for 2024 based on their consistently low-quality ratings. This is an increase of just one contract with the icon last year.
CMS also noted that non-profit organizations tended to earn higher ratings than for-profit organizations, with roughly 56% of non-profit contracts for MA-PDs receiving 4 or more stars compared to 36% for for-profit MA-PDs. PDPs followed a similar pattern, with roughly 50% of non-profit PDPs receiving 4 or more stars compared to 14% of for-profit PDPs.
The length of time in the MA program also seems to have an impact on the star ratings, as MA-PDs with 10 or more years in the program are more likely to have four stars when compared to contracts with less than five years in the program. For PDPs, the relationship is similar.
The CMS website breaks down the average star rating by year by Part C Measure, Part D Measure for MA-PDs, and Part D Measure for PDPs.