CMS Star Ratings
CMS Star Ratings are a 1–5 star quality scoring system applied to Medicare Advantage and Part D plans, directly determining plan bonus payments, member enrollment eligibility, and the leverage MA plans have in provider network contracting.
What are CMS Star Ratings?
CMS calculates Star Ratings annually for each Medicare Advantage and Part D plan using a weighted composite of quality and performance measures. MA Star Rating components include Clinical Quality Measures (40% weight — diabetes care, blood pressure control, breast cancer screening, colorectal cancer screening, medication adherence), Member Experience/CAHPS (30% weight), Access and Availability (10%), and Health Plan Administration (20%). Plans rated 4 or more stars receive quality bonus payments from CMS; 5-star plans receive a 5% bonus on their benchmark payment and uniquely qualify to market and accept members year-round outside the standard annual election period. Plans rated below 3 stars for three consecutive years face enrollment freezes. The Health Outcomes Survey (HOS) contributes to star ratings through functional status and physical/mental health measures. Providers contracted with MA plans increasingly receive performance bonuses tied to the plan's Star Rating outcomes — meaning provider-level clinical performance directly affects plan-level financial results.
Why It Matters for Healthcare Analytics
For providers, Star Ratings performance directly affects value-based contract bonus payments from MA plans and influences which plans are willing to offer preferential network agreements. Key provider-level metrics include HEDIS measures for diabetes, hypertension, and cancer screening, plus CAHPS scores for communication and care coordination. Identifying which patients are attributable to 4- or 5-star plans — and which star measure gaps remain open — is a high-value analytics use case.
How Vizier Tracks Star Ratings
Upload your MA patient roster and ask "Which HEDIS measures are dragging our Star Rating performance by plan?" — Vizier identifies open care gaps by measure, patient, and MA plan to prioritize outreach that improves both clinical outcomes and plan-level Star Rating performance.