Medicare Star Ratings Explained: How CMS Rates Plan Quality (2026)
Medicare Star Ratings are a 1-to-5 scale CMS publishes every fall to score the quality of Medicare Advantage (Part C) and Part D drug plans, where 5 stars is excellent and 1 star is poor. For 2026, CMS rates plans across up to 9 domains and as many as 45 measures covering health outcomes, member experience, customer service, complaints, and drug safety. The overall rating is a weighted average of those measure scores, and you can use it on Medicare Plan Finder to compare plans before you enroll.
What Medicare Star Ratings Are
The Centers for Medicare & Medicaid Services (CMS) publishes Star Ratings each year to measure the quality of care and service delivered by Medicare Advantage (Part C) plans and standalone Part D prescription drug plans. Ratings run from 1 star (poor) to 5 stars (excellent) in half-star increments, and CMS releases them in the fall so you can use them during the Fall Open Enrollment window that runs October 15 to December 7.
Star Ratings apply only to Medicare Advantage and Part D plans sold by private insurers. They are not the same as the separate Star Ratings CMS publishes for hospitals and nursing homes on Care Compare. Original Medicare (Part A and Part B) is not rated, because it is administered directly by the federal government rather than by competing private plans.
The goal is to give you and your caregivers a single, comparable quality signal to weigh alongside premiums, deductibles, drug coverage, and provider networks when choosing a plan.
How CMS Calculates the Ratings for 2026
CMS scores each plan on dozens of individual quality measures. For the 2026 Star Ratings, a Medicare Advantage plan with drug coverage (MA-PD) can be measured on up to 9 domains and as many as 45 measures. A Medicare Advantage plan without drug coverage is measured on up to 5 domains and 33 measures, while a standalone Part D drug plan is measured on 4 domains and up to 12 measures.
For every measure, CMS sets thresholds called 'cut points' that determine whether a plan earns 1, 2, 3, 4, or 5 stars on that measure. Measures are then averaged into domain and summary scores, and the overall Star Rating is a weighted average of the Part C and Part D measure stars — so higher-weighted measures, such as health outcomes, move the overall score more than lower-weighted ones.
CMS continues to adjust the program year to year. For 2026, the 'Improving or Maintaining Physical Health' and 'Improving or Maintaining Mental Health' measures carry a weight of one, rising to a weight of three starting with the 2027 Star Ratings. CMS also applied disaster adjustment provisions — for example, the January 2025 Los Angeles County wildfires qualified as an extreme and uncontrollable circumstance for certain member-experience (CAHPS) measures in the 2026 ratings.
What the Measures Actually Measure
The individual measures fall into broad categories so that a rating reflects both clinical quality and the day-to-day experience of being a member:
- Health outcomes — whether members' physical and mental health is maintained or improved, and management of chronic conditions
- Intermediate outcomes — actions that support better health, such as controlling blood pressure or blood sugar
- Patient/member experience — survey-based ratings of the plan, getting needed care, and getting needed prescription drugs
- Access and process — timely decisions on appeals, preventive screenings, and other services that can create or remove barriers to care
- Customer service and complaints — call-center performance, problems getting services, and members choosing to leave the plan
- Drug safety and pricing accuracy — medication adherence for conditions like diabetes and accuracy of drug pricing for Part D
The 5-Star Special Enrollment Period
High ratings come with a real enrollment perk. If a Medicare Advantage Plan, Medicare Cost Plan, or Part D drug plan with an overall 5-star rating is available in your area, you can use the 5-star Special Enrollment Period to switch into it — once — between December 8 of the year before the plan year and November 30 of the plan year.
There is an important catch: if you move from a Medicare Advantage plan that includes drug coverage to a 5-star Medicare Advantage plan that does not include drug coverage, you can lose your prescription drug coverage. You would then have to wait for your next enrollment opportunity to add a drug plan, and you may owe a Part D late enrollment penalty. That penalty is calculated as 1% of the national base beneficiary premium ($38.99 per month in 2026) multiplied by the number of full months you went without creditable coverage.
Always confirm a plan's current rating on the official Medicare Plan Finder at Medicare.gov before relying on the 5-star SEP, since ratings are updated annually.
How to Use Star Ratings When Choosing a Plan
Star Ratings are a quality screen, not the whole picture. A 5-star plan is generally a strong signal of good service and outcomes, but it still has to fit your budget, your doctors, and your medications.
Use the rating as a starting filter, then dig into the specifics that affect your wallet and your care.
- Compare ratings on Medicare Plan Finder at Medicare.gov, where each plan's overall and summary stars are listed alongside costs
- Check the measures that matter most to you — for example, drug safety and member experience if you take several prescriptions
- Weigh the stars against premiums, deductibles, copays, the Part D out-of-pocket cap ($2,100 in 2026), and whether your providers and drugs are covered — benefits vary by plan
- Remember that plan benefits, networks, and ratings can change every year, so re-check during Fall Open Enrollment (October 15 – December 7)
Frequently asked questions
What is a good Medicare Star Rating?
Ratings of 4 stars or higher are generally considered above average, and 5 stars is the top score CMS gives for excellent quality. A 3-star plan is average, while 1 or 2 stars indicates below-average or poor performance. Use the rating alongside cost and coverage details, since the best plan for you depends on your doctors, drugs, and budget.
How often are Medicare Star Ratings updated?
CMS updates Star Ratings once a year and releases them in the fall, ahead of Fall Open Enrollment (October 15 to December 7). A plan's rating can rise or fall from one year to the next, so it's worth re-checking each year on Medicare Plan Finder rather than assuming a past rating still applies.
Do Star Ratings apply to Original Medicare?
No. Star Ratings apply only to Medicare Advantage (Part C) plans and standalone Part D drug plans offered by private insurers. Original Medicare (Part A and Part B) is run directly by the federal government and is not assigned a Star Rating. CMS does separately rate hospitals and nursing homes, but that is a different rating system.
Can I switch plans because of Star Ratings?
Yes, if a 5-star plan is available in your area. The 5-star Special Enrollment Period lets you switch into a 5-star Medicare Advantage, Cost, or Part D plan one time between December 8 of the prior year and November 30 of the plan year. Be careful moving to a 5-star plan without drug coverage, as you could lose Part D coverage and face a late penalty.
What do the measures in a Star Rating include?
Measures span health outcomes (like staying healthy and managing chronic conditions), member experience surveys, customer service and complaints, timeliness of appeals, and — for drug coverage — medication adherence and drug pricing accuracy. CMS sets cut points for each measure and combines them into a weighted overall score, so no single measure determines the rating.
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Medicare Login Guide is an independent resource and is not affiliated with or endorsed by Medicare, the Centers for Medicare & Medicaid Services, or any government agency. This article is for general information only — confirm current figures and your specific options at medicare.gov or by calling 1-800-MEDICARE.