Medicare Star Ratings 2027: What Changed and How to Use Them Before Open Enrollment

Sometime in early October — usually just a week or so before the Annual Enrollment Period opens on October 15 — the Centers for Medicare & Medicaid Services quietly updates a number on Medicare.gov next to every Medicare Advantage and Part D plan: its Star Rating. Almost nobody notices the moment it happens. But that single number drives which plans get bonus payments, which plans can afford to keep offering dental and vision extras, and which beneficiaries get a rare chance to switch plans outside the normal enrollment window.

Star Ratings aren't a marketing score — they're built from dozens of measures CMS pulls from claims data, plan audits, and the CAHPS member survey. Broadly, they track four things: preventive care (screenings, vaccinations, annual wellness visits), chronic condition management (how well a plan keeps diabetes, heart disease, and other conditions controlled), drug safety and accuracy (Part D measures like medication adherence and pricing accuracy), and member experience (complaints, call center performance, and how easy the plan is to use).

Each individual measure gets its own star score, and those roll up into one overall rating per plan — the number you actually see on Medicare.gov's Plan Finder. It's the single fastest way to compare plan quality side by side, which is exactly why it's worth checking before, not after, you enroll.

CMS has a consistent pattern: the ratings for next year's plan year post in early October, just ahead of the October 15 start of Open Enrollment. That means beneficiaries get only a short window to see the new numbers before they need to decide whether to stay put or switch plans by December 7.

That short window is exactly why waiting until late November to compare plans is risky. Checking ratings the moment they post gives you the full six-plus weeks of AEP to actually act on what you find, instead of scrambling in the final days before December 7.

CMS updates the Star Ratings methodology most years, but the 2027 changes are more than the usual tune-up:

• Ten measures removed. Six applied only to Medicare Advantage, one only to Part D, and three applied to both — including several call-center and medication-related measures plans had pushed back on.
• A new measure added. Plans are now also scored on the share of members screened for clinical depression who, if they screen positive, receive follow-up care within 30 days.
• Roughly half of quality thresholds got harder to clear. Many cutpoints are set relative to how the whole industry performs, not against a fixed bar — so as plans across the board improve, the bar for each star level rises with them.

Bonus payments aren't an abstract accounting detail — they're often exactly where a plan's dental allowance, vision coverage, hearing aid benefit, or over-the-counter (OTC) card comes from. Plans rated 4 stars or higher receive quality bonus payments from CMS, and many reinvest that money directly into the extra benefits members shop for. When a plan's rating slips below that 4-star threshold, those extras are often the first thing trimmed the following plan year — sometimes with little advance warning beyond the Annual Notice of Change letter.

That's the practical reason to check your own plan's 2027 rating the moment it posts, rather than assuming this year's benefits carry over unchanged.

Most Medicare enrollment changes are locked to specific windows — AEP in the fall, the Medicare Advantage Open Enrollment Period in the winter, or a qualifying life event the rest of the year. The 5-star SEP is the exception. If a Medicare Advantage plan, standalone Part D plan, or Medicare Cost Plan in your area carries an overall 5-star rating, you can make a one-time switch into it any time the SEP is active — running annually from December 8 through November 30 of the following year.

• You can generally use this SEP only once during that window.
• It only applies if a qualifying 5-star plan is actually offered where you live — availability varies a lot by county.
• 5-star plans are relatively rare: CMS awarded the designation to only a small handful of contracts for 2026, and the 2027 list won't be known until the new ratings post.

In practice, this SEP matters most for beneficiaries who already own a lower-rated plan and discover, mid-year, that a 5-star option has opened up nearby — it's a safety valve, not a replacement for shopping carefully during AEP.

1. Go to Medicare.gov's Plan Finder and search your ZIP code once the 2027 ratings post in October — every plan available in your area is listed with its current star score.
2. Compare your current plan's new rating against last year's, and against at least two or three alternatives in your area.
3. Read your Annual Notice of Change (ANOC), mailed by September 30, alongside the rating — a dropped benefit often shows up there before the rating story is obvious.
4. Call 1-800-MEDICARE or a licensed local agent if the numbers don't add up — a rating alone won't tell you whether your specific doctors and drugs are still covered well.

Star Ratings are one of the few plain, comparable numbers in the entire Medicare system — but 2027's methodology shake-up means the number alone tells only part of the story. Check the new ratings as soon as they post in early October, read them against your ANOC letter, and don't assume a shifted score means your plan actually got better or worse. If a 5-star plan is available near you and your current plan isn't holding up, remember you're not limited to the fall — that SEP runs nearly all year.

Want more plain-English Medicare guides like this? Visit the blog, read our ANOC letter checklist, or explore our free Medicare education center.