Medicare Star Ratings Explained: How to Read and Use Them

Medicare star ratings are a 1 to 5 quality score that the federal government gives every Medicare Advantage and Part D drug plan contract each year. Five stars is excellent and one is poor. The score tells you how well a plan has performed for its members on care, service and drug safety. It does not tell you whether your doctors, your prescriptions and your budget fit the plan. Use the stars as a first filter, then check the details that are specific to you. Our licensed, independent brokers at Simply Insurance do that second step with Colorado residents every fall.

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TL;DR

• Stars apply to Medicare Advantage (Part C) and Part D drug plans, not to Original Medicare or Medigap. CMS publishes them each year and shows them in Medicare Plan Finder.
• The scale runs from 5 (excellent) to 1 (poor). Scores are built from dozens of measures, such as screenings, member experience, complaints and drug safety.
• A rating belongs to a contract, which can cover many local plans. It will not show whether your doctors and drugs are covered.
• Compare stars only after you confirm your doctors, pharmacies, drugs and total yearly costs.
• New ratings come out every fall, before the annual October 15 to December 7 enrollment window, and they can change from year to year.

Table of Contents

• What Medicare star ratings are
• What each star level means
• What the stars actually measure
• How CMS turns measures into one rating
• What changed for 2027
• Why stars matter beyond the label
• What the stars can and cannot tell you
• How to use star ratings step by step
• A quick example
• Where a broker fits
• Talk to a local broker about your plan options
• FAQ
• Sources

What Medicare star ratings are

Every year the Centers for Medicare & Medicaid Services (CMS), the federal agency that runs Medicare, grades private Medicare plans. CMS publishes the Medicare Advantage (Part C) and Part D Star Ratings annually to measure the quality of health and drug services people receive. It displays them in Medicare Plan Finder next to each plan’s benefits and costs, so you can compare them side by side.

Two details trip people up.

First, stars only exist for plans run by private insurers under contract with Medicare. That means Medicare Advantage plans (Part C), including those that bundle drug coverage, and standalone Part D prescription drug plans. Original Medicare itself does not get a star rating, and neither does a Medicare Supplement (Medigap) policy. If you are weighing Original Medicare plus Medigap against Advantage, our Medicare Advantage vs. Medigap guide lays out the trade-offs, and stars come into play only if you land on the Advantage or Part D side.

Second, the rating is attached to a contract, not always to the exact plan you are looking at. We come back to that below because it is the most important thing to understand before you lean on the stars.

What each star level means

CMS describes the scale this way, according to its 2026 Star Ratings Technical Notes:

Stars Meaning 5 Excellent 4 Above average 3 Average 2 Below average 1 Poor

Ratings use half-star steps, so you will see scores such as 3.5 or 4.5. A plan with 4 or more stars is generally treated as a strong performer, and that matters to the plan too, which we explain in a later section.

What the stars actually measure

The number you see is a summary of many smaller scores. For 2027, CMS rates MA-PD contracts on up to 43 measures, MA-only contracts on up to 32, and standalone drug plans on up to 13. An MA-PD contract is an Advantage plan that includes drug coverage. An MA-only contract does not.

Medicare Interactive, a nonprofit consumer education site, groups the Advantage measures into five categories:

1. Staying healthy: screenings, tests and vaccines.
2. Managing chronic conditions.
3. Plan responsiveness and care.
4. Member complaints and members leaving the plan.
5. Customer service.

Part D drug plans are rated in four categories: drug plan customer service, complaints and members leaving the plan, member experience, and drug pricing and patient safety.

Where does the data come from? The measures draw on a mix of sources: member surveys about their experience, clinical and claims data, and plan operations. You do not need to memorize the sources. What matters is that a rating blends how members feel about the plan with how the plan performs on care and drug safety.

How CMS turns measures into one rating

The math is worth understanding at a high level, because it explains why a plan can have an excellent drug rating and a middling medical rating.

Step 1: each measure gets its own stars. CMS converts every measure’s raw score into 1 to 5 stars using clustering or relative distribution methods. In plain terms, plans are grouped by how they performed relative to each other, and the cut points between star levels are set from that grouping. Under the federal rule, a guardrail limits how far a cut point can move from one year to the next, so a plan is not thrown around by sudden shifts in the bar.

Step 2: measures are combined. Similar measures are averaged into domain ratings. Then CMS calculates a Part C summary rating, a Part D summary rating and, for plans with drug coverage, an overall rating. Domain ratings are unweighted averages, while the summary and overall ratings are weighted averages.

Step 3: weights decide what counts most. Not every measure counts equally. Under 42 CFR 422.166, improvement measures carry a weight of 5, outcome measures 3, and process measures 1. Patient experience, complaint and access measures carried a weight of 4 through the 2025 ratings and 2 starting with 2026. A measure with weight 3 counts three times as much as a measure with weight 1.

Why this matters to you: a plan’s overall star number can hide a lot of variety. A plan might do well on screenings and customer service, which many measures reward, and less well on something you care about more. That is why you look at the category scores in Plan Finder and not only the headline number.

What changed for 2027

CMS updates the system regularly, so a plan’s stars from one year are not a straight comparison with the next. For 2027, CMS added two measures, brought back a respecified measure, and raised the weight of two Health Outcomes Survey measures from 1 to 3. The 2027 ratings are the ones displayed in Plan Finder for the open enrollment period that runs October 15 to December 7, and they affect 2028 quality bonus payments to plans.

The year before, the 2026 ratings lowered the weight of patient experience, complaint and access measures from 4 to 2 and added a kidney health evaluation measure for people with diabetes.

Looking ahead, in an April 2026 final rule for contract year 2027, CMS finalized a streamlined measure set that removes some measures focused on administrative processes. The practical takeaway is simple: a plan that moved from 4.5 to 4 stars may not have gotten worse. The yardstick may have changed.

The official place for the current data tables is the CMS Part C and D Performance Data page, which was updated with the 2027 tables on October 8, 2026. Check it, or Plan Finder, for the live numbers rather than relying on any figure you saw in an older article.

Why stars matter beyond the label

Stars affect more than your choice. Plans that reach four stars or more are eligible for quality bonus payments from Medicare. CMS notes that each year’s ratings affect the quality bonus payments for a later year, which is why insurers pay close attention to them and why you will see them in marketing.

For you, that creates a useful reality check. A high rating is not just a plan’s own opinion of itself. It comes from a federal scoring method applied to every contract in the same way.

What the stars can and cannot tell you

This is the part most explainers rush through, and it is where the stars either help you or mislead you.

A rating covers a contract, which may include many plans. AARP’s Public Policy Institute explains that star ratings use data from multiple plans within a contract, so they cannot convey the quality of a specific local plan. A contract might include plans sold in more than one county or state. So the 4-star plan you see in Castle Pines may be rated on results that blend in members elsewhere.

The ratings emphasize certain things. The same AARP analysis points out that the measures lean toward preventive-care clinical measures and include relatively few outcome measures such as avoidable hospital stays. The Commonwealth Fund adds that experts see the stars as a good way to screen out the lowest performers, but not to judge how well a plan serves people like you.

They do not know your life. Stars say nothing about whether your cardiologist is in the network, whether your pharmacy is preferred, or what your specific medications cost on each plan’s drug list. Those facts decide your real experience.

The best use of stars, then, is as a sorting tool. Start by dropping plans with low ratings, then compare the rest on what matters to you personally.

If you or a spouse live with several chronic conditions or a serious illness, the question of how much support a plan provides at home matters too, and stars will not answer it. This overview of Medicare and home care coverage explains where coverage ends and what families often have to plan for.

How to use star ratings step by step

Here is a routine that puts the stars in their proper place.

1. Start with your own list

Write down your doctors and specialists, the hospital you would use, your pharmacy, and every prescription with its dose. Without this list, a comparison is guesswork. Our Find Medicare Providers Near You page can help you look up providers in your area.

2. Pull the plans available in your ZIP code

Plans, premiums and ratings differ by county. Medicare Interactive notes that you can see ratings in Medicare’s Plan Finder or by calling 1-800-MEDICARE, and that new ratings are released each fall.

3. Use the stars as a filter

Set aside plans with low overall ratings, and look at the category scores for the rest. If you take many medications, give extra weight to the drug plan categories: customer service, member experience, and drug pricing and patient safety. If you see doctors often, look at the care and responsiveness categories.

4. Confirm coverage before you trust the number

Medicare Interactive advises making sure first that a plan’s coverage and costs suit your needs, for example that a Part D plan covers your drugs at a cost that works for you. A 5-star plan that leaves out your medication is not a good plan for you.

5. Add up the real cost for the year

Look at premium, deductible, copays, coinsurance and the out-of-pocket maximum together. Our Medicare Cost Calculator can help you see the full picture.

6. Mind the calendar and the penalty rules

If you are new to Medicare, the enrollment windows decide when you can pick or switch a plan. See our Medicare Enrollment Periods Explained and enrollment timeline. If you are going without drug coverage, check what a gap could cost with the Part D penalty calculator.

7. Switch without a coverage gap

If you move to a new Advantage plan, timing matters. Our guide to avoiding gaps when changing Medicare Advantage in Colorado covers the sequence.

A quick example

Say you are turning 65 in Castle Pines and you take three regular prescriptions and see one specialist in Denver. Plan Finder shows you four Advantage plans with drug coverage. Two are rated 4 stars or above, one is 3.5 and one is 3.

You set the 3-star plan aside. Of the other three, one does not include your specialist in its network, so you set that aside too. That leaves two plans with strong ratings and your doctor. Now you compare drug costs, premium and out-of-pocket maximum. The decision comes down to total cost and how the plans handle your medications, with the stars having done their job of narrowing the field.

That is the right role for the stars: they get you from a long list to a short one.

Where a broker fits

Stars are one data point among many, and building the short list by hand takes time. If you would rather have it done with you, our Medicare Advantage consultation and Annual Enrollment (AEP) support cover exactly that comparison across multiple carriers. Our description of the work is simple: licensed, independent brokers who compare plans against your doctors, drugs and budget, then stay with you after enrollment for claims help and annual reviews. Our Appeals & Grievances service is there if something goes wrong with a claim or coverage decision.

The annual review matters because a plan’s stars, its formulary and its costs can all change from one year to the next. A plan that was right for you last year deserves a fresh look each fall.

Our perspective on star ratings

When people sit down with us, they usually bring one question: which plan has the most stars? We understand why. A number feels safe.

Our view is that the stars are a good start and a poor finish. We use them to cut the field, since a federal quality score applied to every contract is a useful filter. Then we turn to what the number cannot see: your doctors, your pharmacy, your medications, and what you will really pay over a year.

Because we are independent and work across multiple carriers, we are free to build the short list around you instead of around one company’s product. We also stay in the picture after enrollment. Ratings are refreshed every fall, and plans change what they cover, so we review your plan with you each year and help with claims if you need it.

If you are in Castle Pines or anywhere in Colorado, that local, ongoing relationship is what we think makes the difference between picking a plan and having a plan that keeps fitting.

Zach

Talk to a local broker about your plan options

We offer Medicare planning, Medicare Advantage consultations, Plan G and Plan N quotes, and help with annual enrollment for Castle Pines and Colorado residents. Our work with you carries no direct cost to you, since carriers compensate us when you enroll.

To see everything we handle, visit our services page, or start with our Medicare Guide to get oriented. If you prefer a conversation, Medicare Planning is the place to begin.

FAQ

Does Original Medicare have star ratings?

No. Star ratings apply to Medicare Advantage plans and Part D prescription drug plans run by private insurers. Original Medicare and Medigap policies are not rated this way. CMS publishes the Advantage and Part D ratings each year in Plan Finder.

When do new star ratings come out?

They are released each fall, ahead of the annual enrollment window of October 15 to December 7. CMS posted the 2027 ratings data tables on October 8, 2026. The agency’s Part C and D Performance Data page is where the official tables appear.

Is a 5-star plan always the best choice?

Not automatically. The rating is for the contract and not for you, so it cannot tell you whether your doctors, pharmacy and medications are covered or what your total costs will be. A 4-star plan that fits your doctors and drugs can be a better choice than a 5-star plan that does not.

Where can I see a plan’s stars?

You can see them in Medicare’s Plan Finder, or by calling 1-800-MEDICARE, according to Medicare Interactive. You can also ask us to pull up the plans in your ZIP code and walk through the ratings with you.

Do star ratings change every year?

Yes. Plans’ performance changes, and so does the scoring method. CMS adjusted measures and weights for 2026 and again for 2027, so compare each year’s ratings on their own terms.

Sources

• 2027 Medicare Advantage and Part D Star Ratings, CMS
• 2026 Star Ratings Fact Sheet, CMS
• Medicare 2026 Part C & D Star Ratings Technical Notes, CMS
• Part C and D Performance Data, CMS
• 42 CFR 422.162, eCFR
• 42 CFR 422.166, eCFR
• How to compare plans using the Medicare Star Rating System, Medicare Interactive
• Medicare Advantage Star Ratings and Quality Bonus Payments, AARP Public Policy Institute
• Taking Stock of Medicare Advantage: Quality Reporting and Quality Bonuses, The Commonwealth Fund
• CMS finalizes policy and technical changes to Medicare, MA, Part D for CY 2027, AHA News

Recommended

• Medicare Star Ratings 2026: What They Mean and How to Use Them
• Medicare Guide — Your Questions Answered
• Medicare Cost Calculator
• Medicare Parts A, B, C & D Explained