June 9, 2026
Enrollment data published by CMS indicates that the Medicare Advantage (MA) market remains stable, with continued growth of 1.1 million new enrollees in 2026 and an increase in MA penetration to 51.6% driven by SNPs and non-SNP HMOs. This growth occurred despite previous concerns of enrollment losses from industry stakeholders. These findings are part of a new issue brief in which ARC has taken stock of the current state of the MA market by exploring market and parent organization enrollment trends, as well as enrollment-weighted supplemental MA and Part D benefit trends.
While overall enrollment continues to increase, ARC finds that the market share of the largest carriers began declining in 2024 and continues to decrease into 2026, with smaller insurers seeing meaningful growth over this period. In 2026, smaller insurers grew by 10% compared to growth of only 1% for the largest seven carriers.
Despite enrollment growth, there were approximately 3 million MA beneficiaries impacted by plan terminations in 2026. ARC’s results suggest that most were able to select an alternative MA plan.
Read ARC’s full research brief here. The appendix is available here.
Read Arnold Ventures’ summary of ARC’s findings and related research here.