Medicare 2026

Medicare Star Ratings Explained: What the Stars Measure and What They Don't

Every fall, the Centers for Medicare & Medicaid Services (CMS) posts Star Ratings for Medicare Advantage and Part D plans. You'll see them on plan finders, in mailers, and in conversations with friends who swear by "a five-star plan." The ratings are a useful piece of information — but they're often misunderstood. Here's a plain-English look at what the stars actually measure, what they don't, and how to use them without letting them do all your thinking for you.

What the stars actually measure

CMS rates Medicare Advantage plans and stand-alone Part D plans on a 1-to-5 scale each fall. The scoring pulls together dozens of individual measures, which generally fall into a few buckets:

• Preventive care and screenings — are members getting recommended vaccines, cancer screenings, and wellness visits?
• Managing chronic conditions — how well does the plan support members with diabetes, high blood pressure, heart disease, and similar ongoing conditions?
• Member experience — surveys that ask members how easy it is to get appointments, get needed care, and understand their coverage.
• Member complaints and plan performance — how often members leave, file complaints, or run into problems the plan has to fix.
• Customer service — call-center responsiveness, timely appeals decisions, and accurate information to pharmacies and providers.

For Part D specifically, there are also drug-safety and pricing-accuracy measures — for example, whether the plan quotes prices to pharmacies correctly and whether members on certain high-risk medications are managed safely.

CMS blends all of those measures into an overall star score. Plans can earn half-stars too (3.5, 4.5), so the ratings are more nuanced than a simple five-point ladder.

What the stars don't tell you

The ratings describe the plan's overall quality signals — not whether the plan is right for you. Stars don't tell you:

• Whether your doctors, hospitals, or preferred pharmacies are in-network.
• Whether your specific medications are on the formulary, what tier they're on, or what you'd pay for them.
• What the monthly premium, deductible, or copays look like in your area (these vary plan by plan and place to place).
• Which extra benefits a plan offers, or how robust its out-of-area coverage is.

A high-rated plan with the wrong drug list can cost you more than a modestly rated plan whose coverage lines up with your prescriptions. The stars are a quality snapshot, not a personal fit score.

The five-star Special Enrollment Period

Here's one place the rating has a direct, concrete effect: if a Medicare Advantage plan or Part D plan in your area carries an overall rating of five stars, there's a Special Enrollment Period that lets you switch into it once between December 8 and November 30. You can only use it once in that window, and the five-star plan has to be available where you live. Outside of that, most people make Medicare Advantage and Part D choices during Annual Enrollment, October 15 – December 7, 2026, with coverage starting January 1, 2027.

What "no rating" means

Sometimes a plan shows no star rating at all. Usually that's because it's new and hasn't been operating long enough for CMS to collect the data needed to score it. That's a statement about the plan's age, not a thumbs-down on quality. If you're considering a plan without a rating, lean more on the specifics — network, formulary, cost-sharing — and less on the (missing) stars.

Where the stars fit into a broader decision

Many people weigh Medicare Advantage against Original Medicare paired with a stand-alone Part D plan (and often a Medigap policy). Both paths have real trade-offs:

• Medicare Advantage typically bundles medical and drug coverage, often with networks and prior-authorization rules; plans may include extras and have annual out-of-pocket maximums.
• Original Medicare with Part D (and often Medigap) generally lets you see any provider who accepts Medicare, with more predictable cost-sharing when Medigap is in place, but drug coverage and supplemental coverage are separate purchases.

Star Ratings apply to Medicare Advantage and Part D — not to Original Medicare or Medigap. So the stars are helpful for comparing within the Advantage/Part D world, but they don't help you choose between the two broader approaches. That choice depends on your providers, prescriptions, travel patterns, risk tolerance, and budget.

A few program facts worth knowing

Independent of star scores, some national Part D numbers are already set for 2027:

• The Part D out-of-pocket cap rises to $2,400 in 2027 (it's $2,100 in 2026).
• The maximum Part D deductible a plan may charge in 2027 is $700.
• The Part D base beneficiary premium for 2027 is $41.33 — a national figure used to calculate the late-enrollment penalty; actual plan premiums are set plan by plan.
• Social Security announced a 3.6 percent COLA for benefits payable beginning January 2027.

The 2027 Part B standard premium and deductible, along with the IRMAA income brackets, haven't been announced yet; CMS typically releases them in the fall, usually November.

If you have Medicaid or Extra Help

Since 2025, people with Medicaid or Extra Help have a monthly Special Enrollment Period to move to Original Medicare with a stand-alone Part D plan, or to switch stand-alone Part D plans. Full-benefit dual-eligible individuals can join an integrated D-SNP in any month. These monthly options exist whether or not a plan is five stars.

What does this mean for people with Medicare?

Treat Star Ratings as a quality signal — one useful input among several. Match the plan's network, formulary, and costs against your own doctors, drugs, and budget before deciding. For official plan details and current ratings in your area, go to Medicare.gov or call 1-800-MEDICARE (1-800-633-4227), TTY 1-877-486-2048, available 24/7.