Medicare plan quality and CMS Star Ratings
Each year, the Centers for Medicare and Medicaid Services (CMS) rate the quality of Medicare Part D and Medicare Advantage plans using various measures. In the end, an overall Star Rating is calculated for each Medicare plan. A summary rating of prescription drug plan quality and a separate summary rating of health plan quality are calculated where appropriate. Star Ratings are also awarded for various discrete aspects of Medicare Part D and Medicare Advantage plans. New Medicare Part D or Medicare Advantage plans naturally do not have any historical information, so they will not have any Star or quality ratings for the first year.This section explains how the overall CMS Star Ratings are calculated and provides examples of plan quality.
Overall Star Rating
The Overall Star Rating combines scores for the types of services each plan offers: What is being measured?- For plans covering only health services and not offering prescription drug coverage (MAs) the overall quality score is the same as the Summary Rating of Health Plan Quality. This star rating covers many different health services topics that fall into 5 categories.
- For plans covering only drug services (PDPs), the overall quality score is the same as the Summary Rating of Prescription Drug Plan Quality. This star rating covers many different drug services topics that fall into 4 categories.
- For plans covering both health and drug services (MAPDs), the overall score for quality of those services covers all of the topics below.
- Click here for the 2026 Quality Star Rating data source information, category weights, and examples.
Summary Rating of Prescription Drug Plan Quality
This summary rating gives an overall score on the drug plan’s quality and performance in many different topics that fall into 4 categories:- Drug plan customer service: Includes how well the plan handles member appeals.
- Member complaints and changes in the drug plan’s performance: Includes how often Medicare found problems with the plan and how often members had problems with the plan. Includes how much the plan’s performance has improved (if at all) over time.
- Member experience with plan’s drug services: Includes ratings of member satisfaction with the plan.
- Drug safety and accuracy of drug pricing: Includes how accurate the plan’s pricing information is and how often members with certain medical conditions are prescribed drugs in a way that is safer and clinically recommended for their condition.
Summary Rating of Health Plan Quality
This summary rating gives an overall score of the plan’s quality and performance on many different topics that fall into 5 categories:- Staying healthy: screenings, tests, and vaccines. Includes whether members got various screening tests, vaccines, and other check-ups that help them stay healthy.
- Managing chronic (long-term) conditions: Includes how often members with different conditions got certain tests and treatments that help them manage their condition.
- Member experience with the health plan: Includes ratings of member satisfaction with the plan.
- Member complaints and changes in the health plan’s performance: Includes how often Medicare found problems with the plan and how often members had problems with the plan. Includes how much the plan’s performance has improved (if at all) over time.
- Health plan customer service: Includes how well the plan handles member appeals.