What are CMS Star Ratings?

CMS Star Ratings

Developed by the Centers for Medicare and Medicaid Services (CMS), Medicare Star Ratings provide eligible individuals with a quick way to compare the quality and performance of Medicare Advantage plans and Part D prescription drug plans. The Star Rating System was created not only to improve health and quality of care for Medicare beneficiaries, but to support CMS efforts to increase accountability for the care provided by physicians, hospitals, and other providers.

Plans eligible for Star Ratings include Medicare Advantage plans without prescription drug coverage (MA only), Medicare Advantage plans with prescription drug/Part D coverage (MA-PD), and Stand-alone Part D prescription drug plans (PD). To calculate a plan’s Star Rating, CMS gathers information from member satisfaction surveys, health plans, and healthcare providers. Ratings range from one to five stars, with one star being the lowest (poor) and five stars being the highest (excellent). Star Ratings are released each year by CMS in October.

How are Star Ratings Evaluated?

Depending on the plan being evaluated, CMS uses 12 to 38 quality and performance measures related to the plan, provider, and specific health care services.

MA Contracts with Part D Coverage (MA-PD)up to 38 measures
MA-only Contractsup to 28 measures
Stand-alone Part D (PDP)up to 12 measures

MA plans are given an overall rating based on 5 categories* with varying number of measures based on the plan being evaluated:


Member Experience – a beneficiary’s experience with the plan, measured using CAHPS (a patient experience survey that measures respondents’ experiences with their health care)
Customer Service – timely processing of appeals and new enrollees; how often the plan had translator and TTY services available
Plan Performance – beneficiary complaints and changes in the plan’s performance
Chronic Conditions – receiving recommended tests and treatments to help manage chronic conditions
Staying Healthy – receiving preventative services like screenings, physical exams, and vaccinations

* Medicare Part D (prescription drug) Star Rating is based on 4 categories: Drug Safety Pricing, Member Experience, Customer Service, and Plan Performance. Drug Safety Pricing is calculated based on the accuracy of the plan’s pricing information and how often people with certain conditions are prescribed medication in a safe and clinically recommended way.

Measures can include:

Plan or Provider MeasuresHealth Services Measures
– Customer Service
– Care Coordination
– Plan Complaints
– Getting Needed Care
– Health Care Quality Rating
– Members Choosing to Leave Plan
– Getting Appointments and Care Quickly
Breast Cancer Screening
– Diabetes Care
Annual Flu Vaccine
– Monitoring Physical Activity
– Colorectal Cancer Screening
– Getting Needed Prescription Drugs
Medication Adherence (Cholesterol or Diabetes)

How did Star Ratings Change in Rating Year 2023?

  • CMS will no longer universally apply the regulatory disaster adjustments for extreme and uncontrollable circumstances trigged by the COVID-19 public health emergency (PHE) provisions, although a few measure-level adjustments will remain in effect
  • Guardrails were introduced to cut points for many measures, creating bi-directional caps and limiting movement of the current year’s Star Ratings
  • Controlling Blood Pressure transitioned from a display measure to a Star Rating new measure
  • Statin Use in Persons with Diabetes measure changed from an intermediate outcome measure with a weight of 3 to a process measure with a weight of 1
  • Rheumatoid Arthritis Management measure was retired
  • Various patient experience measure weights increased from 2 to 4

Why do Star Ratings Matter?

Star Ratings empower Medicare beneficiaries to make health care decisions that are best for them, offering a clear and simple overview of a health plan’s quality and performance. Star Ratings should not be the only factor when evaluating different plans. Coupled with cost and coverage, beneficiaries can choose the plan that best fits their individual health, lifestyle, and financial needs.

To find a Medicare plan’s star rating, go to Medicare.gov plan finder tool.

About the Author

Tresa Shaw, MSN, RN

Tresa Shaw, MSN, RN

Director of Quality at CHESS