The MA STARS Act directs the Secretary of Health and Human Services to revise how Medicare Advantage plans are rated using the federal five-star rating system, beginning with the 2031 contract year. The bill requires the Secretary to exclude certain measures from star rating calculations, such as those not directly related to clinical quality or patient outcomes, measures that plans cannot reasonably control, surveys that are too long or not representative of diverse patient populations, and measures that no longer differentiate performance among plans. The legislation also requires the Secretary to establish two technical expert panels within two years to evaluate survey instruments used in ratings and to recommend reforms to how ratings are calculated and assigned, with the panels including balanced representation from beneficiaries, healthcare providers, insurers, researchers, and other stakeholders. Additionally, starting in 2031, the Secretary must publish an annual public report explaining the distribution of star ratings, the methodology used, and which measures were excluded and why. The bill aims to make the Medicare Advantage rating system more transparent and focused on metrics that genuinely reflect plan performance and quality.