Medicare Star Ratings Explained: How to Use Them to Pick a Plan
If you've ever browsed Medicare Advantage or Part D drug plans on Medicare.gov, you've seen those familiar star icons next to each plan's name. But what do those stars actually measure — and how much weight should you give them when choosing coverage? Here's what you need to know.
What Are Medicare Star Ratings?
Medicare's Star Rating system is a performance scoring program run by the Centers for Medicare & Medicaid Services (CMS). Every year, CMS evaluates Medicare Advantage (Part C) and Medicare Part D prescription drug plans on dozens of quality and performance measures, then assigns each plan an overall rating on a scale of 1 to 5 stars.
- ⭐ 1–2 stars: Below average performance
- ⭐⭐⭐ 3 stars: Average performance
- ⭐⭐⭐⭐ 4–5 stars: Above average to excellent performance
Plans rated 5 stars are considered the highest performing and receive a special designation from CMS.
The goal of the system is straightforward: give Medicare beneficiaries an apples-to-apples way to compare plan quality — not just cost and coverage — before enrolling.
What Do Star Ratings Actually Measure?
Star ratings are built from dozens of individual measures grouped into broad categories. The exact measures and their weights shift slightly from year to year, but they consistently cover areas like:
| Category | What's Being Evaluated |
|---|---|
| Staying healthy | Screenings, vaccines, and preventive care rates |
| Managing chronic conditions | How well members with diabetes, heart disease, etc. receive appropriate care |
| Member experience | Enrollee satisfaction surveys |
| Member complaints | Volume of complaints, coverage denials, and appeal outcomes |
| Customer service | Plan responsiveness and accuracy |
| Drug plan safety (Part D) | Medication adherence, high-risk medication use, drug therapy reviews |
Plans that combine medical and drug coverage (most Medicare Advantage plans) receive a single overall star rating. Stand-alone Part D plans receive their own separate rating.
One important note: star ratings reflect past performance, typically measured over the prior plan year. They're a useful signal — but not a guarantee of what your experience will be.
Why Star Ratings Matter Beyond Quality Bragging Rights ⭐
Star ratings aren't just a consumer tool — they have real financial consequences for plans, which in turn can affect you as a member.
Higher-rated plans receive bonus payments from CMS. Plans that earn 4 or more stars qualify for additional federal funding, which many plans use to offer richer benefits, lower premiums, or added perks like dental and vision coverage. This creates a financial incentive for plans to invest in quality.
There's also an enrollment benefit for high-performing plans. Beneficiaries enrolled in a 5-star plan can switch into that plan at any point during the year — outside of the usual enrollment windows — using a Special Enrollment Period. This is one of the few mid-year enrollment flexibilities available in Medicare.
How to Find and Read Star Ratings
CMS publishes updated star ratings each fall, typically in October, ahead of the Annual Enrollment Period (generally October 15–December 7). You can look up ratings directly on the Medicare Plan Finder at Medicare.gov.
When you search for plans in your area, star ratings appear alongside each plan's premiums, deductibles, and coverage details. You can filter or sort results by star rating to narrow your options.
A few things worth knowing as you read them:
- New plans don't always have a star rating yet — they need a track record before CMS can evaluate them.
- Ratings vary by region. The same insurance company might operate plans in multiple states with meaningfully different ratings in each market.
- Overall vs. individual measure ratings: An overall 4-star plan might score lower on specific measures that matter most to you — like drug plan management or chronic disease care. You can dig into individual measure scores on Medicare.gov for a more detailed picture.
How Much Should Star Ratings Influence Your Decision?
This is where your personal situation matters — and where a single number can only tell you so much.
Star ratings are a useful filter, not a complete answer. Here's how different factors interact with them:
When star ratings deserve significant weight
- You're comparing plans that are otherwise similar in cost and network
- You have chronic conditions where care management quality directly affects your health outcomes
- You've had frustrating experiences with plan administration, claims, or customer service in the past
- You want a plan with a demonstrated track record of member satisfaction
When other factors may matter more
- A lower-rated plan includes your specific doctors, specialists, or hospital in its network, and a higher-rated plan does not
- Your medications are significantly better covered (lower cost-sharing or no prior authorization requirements) under a plan with a slightly lower overall rating
- A newer plan in your area is offering substantially better benefits despite lacking a rating yet
- Your total out-of-pocket costs under a higher-rated plan are meaningfully higher for your expected usage
🔍 The rating reflects average performance across all members. It doesn't tell you how a plan performs for someone with your specific health profile, prescriptions, or care needs.
The Smart Way to Use Star Ratings in Your Search
Think of star ratings as a starting point, not a finish line. A practical approach:
- Filter out low-rated plans (1–2 stars) unless you have a compelling, specific reason to consider one
- Use the Plan Finder's detailed measures to check scores on categories most relevant to your health situation
- Cross-reference network and drug coverage — confirm your providers are in-network and your medications are on the formulary at a cost tier you can manage
- Compare total annual costs, not just premiums — factor in deductibles, copays, and your expected healthcare use
A 4.5-star plan that doesn't cover your cardiologist or charges significantly more for your maintenance medications may serve you worse than a solid 3.5-star plan that fits your actual needs.
One More Thing: Ratings Change Every Year
Plans can move up or down. A plan that earned 4 stars last year might drop to 3.5 this year — or improve to 4.5. CMS ratings are updated annually, so it's worth checking current ratings each fall during Open Enrollment, even if you're staying in the same plan.
If your current plan's rating drops significantly, it's a signal worth taking seriously — and a good reason to shop your options during the enrollment window.
