Medicare Advantage Star Ratings: What They Measure and What They Don’t

What a Star Rating Is, in Plain Terms

Every fall, the federal government publishes Star Ratings for Medicare Advantage plans and Part D drug plans. Each is scored on a scale from one to five stars, with five meaning excellent. The Centers for Medicare & Medicaid Services, which runs the program, publishes the ratings on the Medicare Plan Finder tool at Medicare.gov. For the 2026 ratings, CMS posted them on October 9, 2025, ahead of the open enrollment window that begins October 15. Ratings generally appear in early October, in the days or weeks leading up to that date.

The idea is to give people a quick signal of how well a plan performs on measures of quality and customer experience. It is a summary meant to help with comparison, not a guarantee of how any individual enrollee will be treated.

According to CMS, for the 2026 ratings, plans that include drug coverage were rated on up to 43 separate measures. Plans that cover medical services only were rated on up to 33. Standalone Part D drug plans were rated on up to 12. The exact count shifts as CMS adds and retires measures. Those individual measure scores are combined into a weighted overall rating.

What Goes Into the Number

The measures fall into several broad groups. NCOA describes the categories for Medicare Advantage plans as:

• Member experience with the health plan
• Customer service
• Plan performance and complaints
• Management of chronic conditions
• Preventive health services

For drug plans, the categories are member experience, customer service, plan performance, and drug safety and pricing accuracy.

Underneath those categories are specific measures. Some look at whether members got screenings and vaccines, such as breast cancer screening or colorectal cancer screening. Some look at how well chronic conditions are managed, and others at whether members take medications as prescribed. Others come from surveys that ask members about their experience: how easy it was to get care, how well their doctors communicated, and whether they were satisfied with the plan. A further group tracks complaints, how many members leave the plan, and how quickly the plan handles appeals and calls.

The data comes from several sources, including member surveys, clinical quality data the plans report, and administrative records. Because it takes time to collect and review that information, the ratings reflect performance from an earlier period rather than the year you are about to enroll in. A plan that changed management or contracts recently may be different from what its rating suggests.

How the Five-Star Scale Is Set

One detail surprises people: the ratings are partly relative. CMS sets cut points, which are the thresholds that decide whether a plan earns one, two, three, four, or five stars on each measure, and it recalculates them each year based on how plans performed during the measurement period. A plan’s score on a measure depends on where it falls compared with that year’s thresholds, which are shaped by what other plans achieved.

That means a rating is not a fixed standard of care. A plan could keep doing the same thing from one year to the next and still see its stars move, because the bar moved. CMS also changes the measures and how they are weighted over time. For example, CMS’s fact sheet for the 2026 ratings described lowering the weight of patient experience, complaints, and access measures, and adding a new measure on kidney health evaluation for people with diabetes.

CMS also marks a small number of plans that consistently score low with a low-performing icon on Plan Finder. For the 2026 ratings, CMS reported four Medicare Advantage drug plan contracts carried that icon. If you see it, it is worth paying attention to, although it does not tell you why.

Ratings Belong to Contracts, Not to Plans

This is the point most people miss. Star Ratings are assigned at the contract level, not to each individual plan. An insurer’s contract can include many plans: an HMO with a low premium, another with a richer benefit package, and sometimes plans in different counties. All of them can carry the same rating because they sit under the same contract.

The practical effect is that the stars tell you about the organization’s overall performance, not about the particular plan you are looking at. Two plans with identical stars may differ sharply in premium, copays, drug coverage, and, most important, which doctors and hospitals are in the network. The rating cannot tell you that.

If a plan is new, it may have no rating yet. NCOA notes that new plans simply start without one, so a missing rating is not a red flag in itself. You will need to rely on the other parts of your comparison.

What Star Ratings Do Not Tell You

Your question	Do stars answer it?
Is the insurer generally well run?	Partly, that is what they measure
Is my doctor in the network?	No
Are my drugs covered, and at what cost?	No
What will I pay in premiums and copays?	No
Does this exact plan have this rating?	Not necessarily; ratings belong to contracts

Here is where it gets practical. A star rating does not tell you:

• Whether your doctors and hospitals are in the network. A five-star plan that excludes your cardiologist is a poor fit for you.
• Whether your medications are covered, and at what cost. Drug ratings in Plan Finder look at plan performance, not at whether your specific drugs are on the list.
• What you will pay. Premium, deductible, copays, and the out-of-pocket limit are separate from the rating.
• How the plan will treat your particular situation. Ratings are averages across a large population. They do not predict what happens if you need a complicated approval.
• How good a particular supplemental benefit is. Dental, vision, hearing, and fitness allowances are not what the rating measures.
• Anything about Original Medicare, which is not rated this way.

Think of a star rating as a quick check on how well the insurer runs its operation, much like a restaurant inspection score tells you about the kitchen but not whether you will like the menu.

The Five-Star Special Enrollment Period

There is one place where a star rating changes your options directly. According to NCOA, if a five-star Medicare Advantage or Part D plan is available where you live, you can use a special enrollment period to switch into it once per year. The window runs from December 8 through November 30 of the following year. That is unusual, because most plan changes are tied to the fall enrollment window or to a specific life event.

It is worth knowing about, with some caution. Moving into a five-star plan outside the regular window does not remove the usual cautions. If you are leaving a Medigap policy, you may find that returning to it later is not guaranteed, depending on your state and health. And a five-star plan still has its own network, rules, and costs. Our guide to Ohio’s Medigap rules is worth a look before you give up a supplement policy for any reason.

How to Use Stars Well When You Compare Plans

The best use of a star rating is as an early filter and a late tiebreaker.

As an early filter, it can help you decide where to start. If you are looking at a list of plans in your county, you might look first at those with higher ratings, and take a closer look at any with a low-performing icon before you commit.

As a late tiebreaker, it can help when you have two plans that fit your doctors and drugs and cost about the same. In that case, the one with stronger member satisfaction and better complaint scores may be a better bet.

Between those two points, do the work that stars cannot do:

• Confirm your doctors and hospital are in the network, by calling their offices.
• Check each of your drugs against the formulary and note the tier and any restrictions.
• Estimate your annual cost, including the out-of-pocket limit.
• Read how the plan handles referrals and prior authorization.

Our comparison checklist puts these steps in order. If you want to know how the ratings fit into the larger enrollment calendar, see our overview of the Annual Enrollment Period.

Looking Behind the Rating

If you want more than the summary stars, Plan Finder shows category-level ratings, and CMS publishes the individual measures that make up a rating on its Star Ratings pages. Those are often more useful than the overall number. If you care about customer service because you expect to call the plan often, look at that category. If you manage a chronic condition, look at the chronic condition measures. If you want to see whether members tend to stay, look at the complaints and member-leaving measures.

Remember also that a rating can change from one year to the next, sometimes by a lot. A plan you chose because of four stars may be a three-star plan the following October. That is another reason to review your coverage each fall instead of assuming last year’s reasoning still holds. Reading your Annual Notice of Change is the other half of that review.

Frequently Asked Questions

What do Medicare Advantage star ratings measure?

They measure quality and customer experience in areas such as member satisfaction, customer service, complaints, chronic condition management, and preventive care. Plans with drug coverage are also scored on drug-related measures.

Are star ratings given to each plan or each insurer?

They are assigned to contracts, and one contract can include several plans. That means two plans with the same stars can have very different costs and networks.

Is a five-star plan always the best choice?

No. The rating does not tell you whether your doctors and drugs are covered or what you will pay. It is one input among several and not a substitute for checking your own needs.

When are Medicare star ratings released?

CMS generally publishes them in early October, shortly before open enrollment begins on October 15. For the 2026 ratings, the date was October 9, 2025.

What is the five-star special enrollment period?

If a five-star plan is available in your area, you can generally switch into it once per year using a special enrollment period that runs from December 8 through November 30. Check how it interacts with any Medigap policy you hold before you switch.