CMS Medicare Advantage & Part D: Enrollment, Star Ratings, Plan Benefits & Plan Crosswalk

The Centers for Medicare & Medicaid Services (CMS) Medicare Advantage (MA) and Part D dataset offers an authoritative, macroscopic view of the U.S. Medicare managed care landscape. **Scope and Scale:** This dataset combines three highly sought-after domains into a single, unified analytical environment: - **Monthly Enrollment:** Highly granular enrollment figures broken down by Contract, Plan, State, and County (CPSC) across all 50 states and territories. This data reflects real-time beneficiary choices and is refreshed monthly. - **Star Ratings (Summary & Measure Data):** Annual CMS quality and performance ratings for Medicare Advantage and Part D plans. Includes both the overarching summary ratings (1 to 5 stars) and the underlying domain-specific measure data used to calculate them. - **Plan Crosswalk:** An annual mapping file that bridges the gap between benefit years, illustrating how specific plans transition, merge, or terminate from one year to the next. **The Value Proposition:** Tracking the Medicare Advantage and Part D market typically requires stitching together fragmented monthly ZIP files and annual PDFs from disparate CMS web pages. This dataset eliminates that friction. It enables health plans, pharmaceutical companies, and policy researchers to seamlessly track beneficiary migrations, evaluate competitor quality scores, and map historical plan continuity over time.