Star ratings are one of the most underused tools in Medicare plan selection—and one of the most revealing. CMS developed the five-star quality rating system to give Medicare beneficiaries an objective, data-driven way to assess plan performance. Yet many enrollees still select plans based primarily on premium costs or benefit descriptions, without factoring in quality scores that reflect how a plan actually performs in practice. The best Medicare Advantage plans 2027 will carry star ratings that reflect sustained performance across multiple years, not just a single strong measurement period.
Understanding how star ratings work—and what they measure—can help you make a more informed enrollment decision for 2027.
How CMS Calculates Medicare Advantage Star Ratings
CMS assigns star ratings to Medicare Advantage plans annually, based on performance across more than 40 individual measures grouped into several broad categories:
Staying healthy: Screenings, tests, and preventive care utilization rates
Managing chronic conditions: How well the plan supports members with ongoing health issues
Member experience: Survey-based feedback from current plan members
Customer service: Call center responsiveness, appeals processing, and complaint rates
Access and accuracy: Formulary accuracy and coverage determination timelines
Each measure is weighted differently, and the final composite score determines the plan’s overall star rating on a scale of 1 to 5, with 5 being the highest. Plans are rated separately for their medical coverage and their Part D drug coverage, then combined into an overall rating.
What the Data Shows About High-Rated Plans
Plans with ratings of 4 stars or higher are not just better on paper—they demonstrate measurable differences in member outcomes. According to CMS data from 2024, approximately 70% of Medicare Advantage enrollees were enrolled in plans rated 4 stars or above. High-rated plans are associated with:
Higher rates of preventive screenings and early intervention
Better management of conditions such as diabetes and cardiovascular disease
Faster resolution of coverage appeals and grievances
Higher member-reported satisfaction with care coordination
CMS evaluates trends, so a plan that has maintained 4.5 stars for three consecutive years offers stronger assurance than one that recently climbed from 3 stars.
The Financial Implications of Star Ratings for Enrollees
Star ratings carry financial consequences that directly affect plan quality and benefits. CMS awards quality bonus payments to plans rated 4 stars or higher. These bonuses give higher-rated plans more financial resources, which some insurers direct toward enhanced benefits, lower member premiums, or reduced cost-sharing.
Plans with consistently low ratings—below 3 stars for three consecutive years—face potential sanctions, including removal from the Medicare Advantage program. CMS has exercised this authority in recent years, reinforcing that star ratings are consequential beyond marketing.
How to Use Star Ratings Effectively During Plan Comparison
Star ratings are a signal, not a guarantee. A 5-star plan with a narrow network that excludes your primary care physician may deliver worse personal outcomes than a well-run 4-star plan with broad provider access and a formulary that covers your medications at a lower tier.
Use star ratings as a first-pass filter—eliminating plans rated below 3.5 stars from serious consideration—then evaluate remaining options against your specific health needs.
The Medicare Plan Finder tool at medicare.gov displays current star ratings alongside premium and benefit information, making side-by-side comparison straightforward. If a plan’s rating has shifted significantly year over year, investigate why. CMS publishes measure-level data that can help identify whether a rating drop reflects a systemic issue or a temporary anomaly.
The Bottom Line on Quality and Value in 2027
Premium cost gets most of the attention during Medicare open enrollment. But plan quality—as reflected in star ratings and the underlying performance data—has a more lasting impact on your health and financial outcomes over the course of a full plan year.
Prioritizing a plan that scores well on chronic condition management, member experience, and care access will serve you better than selecting a plan based on a low monthly premium alone.
