During Medicare open enrollment season, people selecting options for 2025 can often choose from a surprising number of Part D drug plans and private insurers’ Medicare Advantage plans. Medicare star ratings can help you narrow down your choices, if you understand what they mean.
But few people on Medicare care to look at the stars, according to KFF’s Health Policy Research Group. “When asked whether these star ratings influenced their decision-making when choosing a plan, the majority of respondents said no,” 2023 report KFF report He says.
They are making a mistake.
What can Medicare star ratings tell you?
Star ratings, which you can find on the Medicare website Plan finder A tool to compare Part D and Medicare Advantage plans (the alternative to original Medicare), offering a brief look at how the plans measure quality and member experience.
“It’s an imperfect system at best, but it’s the best we have,” says Dr. Sachin Jain, president and CEO of SCAN Health Plan, a large Medicare Advantage plan.
In annual ratings given by the Centers for Medicare & Medicaid Services (CMS), 5 stars means excellent, 4 means above average, 3 means average, 2 means below average and 1 means poor. In the Medicare Plan Finder, a 5-star plan has extra significance: a big star with the number 5 in it.
The data used to create these ratings is somewhat outdated, as the 2025 ratings are based on plans’ 2023 performance, says Susannah Grace Treat, a senior consulting actuary at health care consulting firm Wakely.
Medicare Advantage insurers strive for 4 stars or more
Something else you might not know: Medicare Advantage plans (but not Part D plans) get huge bonuses from Medicare if they get at least 4 stars — worth more than $11.8 billion in 2024, according to KFF.
“If they get higher payments, they will likely provide additional benefits,” says Jenny Vogelstein-Pinnick, associate director of the Medicare Policy Program at KFF. “But there doesn’t have to be a one-to-one relationship that a five-star plan will bring more benefits.”
However, some Part D or Medicare Advantage plans get one or two stars. “In practice, it looks like a 2.5-5 star system,” Jain says.
How to detect low performance
If a plan gets less than three stars for three years in a row, Medicare can terminate it, so plans are incentivized to maintain their quality, Treat says. Such low-performing plans appear in the Plan Finder with an inverted red triangle with an exclamation mark inside.
People on these low-performing plans can switch to plans with a rating of 3 stars or better during the Medicare disenrollment special enrollment period between January 1 and December 31.
What goes into a Medicare Star Rating?
Star ratings for Part D and Medicare Advantage consist of up to 40 or 30 measures of quality and performance, respectively. In general, ratings for both types of plans are based in part on member experience, customer service, and plan performance.
Part D evaluations also evaluate the safety and pricing of prescription drugs, while Medicare Advantage evaluations also look at whether members are healthy and whether people with chronic conditions are getting the tests and treatments typically recommended for them.
“If I want to understand how good my experience is with a plan, a star can be an indicator,” Treat says. “It’s not a direct indicator of how good your benefits or your (doctor or hospital) network are.”
5-star medical care unicorns
If you’re the type who just wants to sign up for a 5-star plan, you’re probably out of luck.
CMS has revised its Medicare star rating methodology in recent years, making it very difficult for a plan to get five stars, says Lisa Winters, a consulting actuary at Wakely.
Star ratings have been kept artificially high during the pandemic, so plans won’t be blamed for quality issues beyond their control.
In 2025, only 2% of people with Medicare Advantage/Part D plans and 5% in standalone Part D plans will be in five-star plans, according to CMS. There were significantly more five-star plans for 2024 than in 2025.
When I tested Plan Finder to see Part D and Medicare Advantage options in suburban New Jersey, I didn’t find any 5-star plans.
Treat’s advice to people at open enrollment: “You’ll probably live in an area this year where you won’t even see a five-star plan.”
It’s easier to find 4-star plans
It is much easier to find a plan that is rated at least four stars. “More than 70% of people with Medicare Advantage are enrolled in it,” Penick says.
She noted that 5-star Medicare Advantage plans do not receive larger additional payments than 4-star plans, so insurers generally see little benefit in striving for five stars. However, some insurers seek out 5-star plans because they use that as a marketing tool, Bennick says.
Medicare Advantage plans’ quest to earn at least four stars is why insurers like Humana, UnitedHealth Group, SCAN Health and Elevance Health are challenging CMS in court to get their star ratings revised higher.
Star rating advice for medical care
Here are the do’s and don’ts from experts when evaluating star ratings for Part D and Medicare Advantage during open enrollment:
- Don’t choose or decline a Part D or Medicare Advantage plan just because of its star rating. “I think costs and access to health services or providers are probably at least as important as the overall evaluation of the plan when a person is making a decision,” Penick says. But the star rating may be the deciding factor when choosing between two plans with similar costs and out-of-pocket coverage.
- Don’t panic if a plan’s 2025 star rating is slightly lower than its 2024 rating. The downgrade may be due to a flaw in the way ratings are calculated from year to year. “If you’re seeing a bounce in your plan’s star rating, unfortunately that will likely continue,” says Treat. That’s why it’s best to look at a plan’s star rating history over several years.
- If you’re OK with the cost and coverage for a Part D or Medicare Advantage plan but are concerned about its overall star rating, click the Medicare Plan Finder to get star ratings in subcategories. You’ll be able to see how well the plan scores on specific quality and member satisfaction metrics that matter to you.
“It’s common for plans not to excel at everything,” Treat says. “They always have a weak spot.”
If you’re confused why a Part D plan falters because pharmacists score poorly at helping members manage their medications, it’s because CMS rates plans based on medication adherence, Treat says.
A low rating on this scale indicates that insurer-preferred pharmacies aren’t doing a great job of ensuring members follow doctor’s orders.
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