CMS released 2028 Medicare Advantage Star ratings on October 8 2026, triggering large moves in the share price of three major plan operators. Humana shares rose 16% after the agency data showed the insurer's largest Medicare Advantage contract regained eligibility for federal quality bonus payments.^[1] Alignment Healthcare shares fell 21% following the rating release. CVS Health dropped 4%.^[2] The annual Medicare Advantage enrollment period is open for Medicare Platino beneficiaries.^[4] A separate longitudinal analysis published the same day included 49,843 Medicare Advantage beneficiaries aged 65 and older with type 2 diabetes, examining factors associated with diabetes complications using insurer data from 2016 to 2020.^[3]