Maybe your Medicare Advantage plan dropped your cardiologist in April. Maybe your Part D plan stopped covering a medication you've taken for years. Maybe the customer service line has been a 90-minute wait every time you've called since January. Whatever the reason, you've been telling yourself the same thing most beneficiaries tell themselves between January and October: nothing to do but wait until fall enrollment opens in October. That is one of the most expensive assumptions in Medicare. There is a quiet, year-round Special Enrollment Period — the 5-Star SEP — that lets eligible beneficiaries switch plans in the middle of the year, including right now, in the middle of summer 2026. Almost no one uses it. Almost no one is told about it. Here is exactly how it works.
📋Quick Summary
- Medicare gives every plan a quality score from 1 to 5 stars, updated each fall by the Centers for Medicare & Medicaid Services (CMS).
- If a 5-star Medicare Advantage, MA-PD, or stand-alone Part D plan is available in your area, you can switch into it once between December 8, 2025 and November 30, 2026 — outside of any other enrollment window.
- You don't need a qualifying life event. You don't need to wait for fall. You don't need to justify the switch.
- The number of 5-star plans changed for 2026; some areas gained options, others lost them. You have to look up your county.
- Switching mid-year has real trade-offs — your deductible may reset, your network changes immediately, and any in-progress prior authorizations may need to be re-filed.
- If you do not live in an area with a 5-star plan, this SEP does not apply — but other mid-year SEPs may, especially if your current plan changed its network.
What the 5-Star Special Enrollment Period Actually Is
Every fall, CMS publishes Star Ratings for every Medicare Advantage and Part D plan in the country. The ratings combine roughly forty different measures — how well the plan manages chronic conditions, how members rate their experience, how often the plan resolves complaints, how accurate its provider directory is, how quickly it processes appeals. Each plan ends up with a single number between 1.0 and 5.0 stars, rounded to the nearest half-star. The ratings are designed to give beneficiaries a quick, comparable signal about quality before they pick a plan during the Annual Enrollment Period.
Most beneficiaries see Star Ratings as informational — a tiebreaker between two plans they were already considering. What very few know is that the ratings come attached to a unique enrollment right. Federal regulations created a Special Enrollment Period, available from December 8 of one year through November 30 of the next, that lets a beneficiary use a single one-time switch to move into a 5-star plan. The window exists specifically because CMS wants to reward top-performing plans and give beneficiaries an off-ramp from poor ones without forcing them to wait the better part of a year.
Two details matter. First, the 5-star plan you switch into must currently have a 5-star overall rating in the area where you live; an individual plan in California rated 5 stars does nothing for a beneficiary in Ohio. Second, the SEP lets you use it once per calendar year — so it is a single bullet, not an open door. Used thoughtfully, it is one of the most powerful options Medicare gives ordinary beneficiaries.
The current 5-Star SEP opened on December 8, 2025 and closes on November 30, 2026. Inside that window, if a 5-star Medicare Advantage plan, a 5-star MA-PD plan, or a 5-star stand-alone Part D plan is offered in your county, you can use this SEP to switch into it — once. After November 30, the SEP based on the 2026 Star Ratings closes; a new one opens December 8, 2026 based on the freshly published 2027 ratings. You do not need a qualifying life event, you do not need a reason, and you do not need to coordinate with the Annual Enrollment Period.
Who Actually Qualifies — and Who Doesn't
Eligibility for the 5-Star SEP comes down to one question: is there a 5-star plan available where you live? The answer is geographic. CMS publishes Star Ratings at the contract level, and each contract serves a specific set of counties. A plan can be rated 5 stars in one state and not even offered in the next. Roughly forty Medicare Advantage contracts earned 5 stars for the 2026 plan year, down from a few more the year before — Star Ratings have generally tightened as CMS has refined its measurement methodology, which means fewer plans qualify in any given area than five years ago.
To find out whether a 5-star plan serves your county, the most reliable tool is the Medicare Plan Finder at Medicare.gov. Enter your ZIP code, then filter the plan results by Star Rating. If the filter shows any 5-star plans for 2026, you're eligible to use the SEP to enroll in one of them. If it shows none, the SEP doesn't apply to you this year — but it doesn't expire your other rights, and you may still have other Special Enrollment Periods open depending on your situation, including ones tied to hospital networks being dropped mid-year or Medigap underwriting challenges.
One important nuance: the type of 5-star plan you switch into determines what you can switch from. If the 5-star plan in your area is a stand-alone Part D plan, you can use the SEP to change Part D plans, but you can't use it to leave Medicare Advantage and return to Original Medicare. If it's a Medicare Advantage Prescription Drug (MA-PD) plan, you can switch into it from another MA plan, from Original Medicare, or from Original Medicare plus a stand-alone Part D plan. The plan type, in other words, defines the move that's available — not just the destination.
📊The 5-Star SEP at a Glance
Why Mid-Year Switching Is Not Always the Right Move
The 5-Star SEP is powerful, which is exactly why it has to be used carefully. Switching plans mid-year is not the same as switching during the Annual Enrollment Period for a January 1 start date. The new plan takes effect on the first day of the month after you enroll, but your deductible and out-of-pocket maximum spending on the old plan do not transfer. If you've already paid down a $400 deductible on your current MA plan by June and you switch into a new one effective July 1, you start over at $0 of credit toward the new plan's deductible and a fresh $2,100 annual prescription drug out-of-pocket cap under the 2026 Part D structure.
Your provider network changes immediately on the switch date. A physician who was in-network on June 30 may be out-of-network on July 1, and the cost difference can be significant — particularly for MA plans that don't cover non-emergency out-of-network care at all. Any prior authorization that was granted by your old plan does not transfer to the new one. If you were scheduled for a hip replacement in August under prior authorization from your current plan, the new plan will require its own approval, which may take weeks. Our coverage of how AI is reshaping prior authorization decisions in 2026 explains why those delays are getting longer, not shorter.
Drug coverage is the most underestimated piece. Every Part D and MA-PD plan has a unique formulary, and a medication that's a $4 generic on your current plan can be a $90 brand-name drug on a 5-star plan — or, worse, not covered at all. Before you switch, run every prescription you take through the new plan's formulary using the Medicare Plan Finder tool. A higher Star Rating is no guarantee that the plan is a better fit for your specific medications.
Run a simple checklist before using the SEP. One: confirm every doctor you currently see is in the new plan's network — call each office directly, do not rely on the online directory, which is frequently out of date. Two: confirm every prescription you take is on the new plan's formulary and check the tier. Three: confirm any pending procedures or referrals will be re-approved under the new plan. Four: write down your current plan's name, your effective end date, and your new plan's start date so there is no coverage gap. Five: keep the new plan's confirmation letter. If you have to dispute coverage of any service in the transition month, that letter is your documentation.
The Other Mid-Year Doors That Are Often Open
The 5-Star SEP is the most universal mid-year option, but it is not the only one. If you live in a county where no 5-star plan is available, several other Special Enrollment Periods may still be open to you in summer 2026. If your Medicare Advantage plan terminated its contract with a major hospital system mid-year, CMS has discretion to grant an SEP for affected enrollees, particularly when the loss of access is described as a "significant" change in the provider network. If you moved to a new permanent address that's outside your current plan's service area, you have a two-month SEP starting the month you move. If you became eligible for Medicaid or for Extra Help with prescription drug costs during the year, that triggers its own SEP and an immediate ability to switch plans.
There is also the Medicare Advantage Open Enrollment Period, which runs January 1 through March 31 each year. That window has already closed for 2026 — but it's worth knowing it exists for next year, because it lets MA enrollees switch to a different MA plan or return to Original Medicare once during the first quarter, no qualifying event required. Between MA-OEP, the 5-Star SEP, and the various life-event SEPs, the assumption that nothing can be changed outside of fall enrollment is simply not true for most beneficiaries.
What Happens to Your Medigap or Part D When You Switch
If you currently have Original Medicare with a Medigap (Medicare Supplement) policy and a stand-alone Part D plan, using the 5-Star SEP to switch into a 5-star Medicare Advantage plan disenrolls you from your stand-alone Part D plan automatically — but it does not automatically cancel your Medigap policy. You have to cancel that yourself by contacting your Medigap insurer. If you don't, you'll continue paying premiums for a policy that, by law, can't pay any of your out-of-pocket costs while you're enrolled in Medicare Advantage.
The harder problem is what happens if you change your mind. If you switch from Medigap into a Medicare Advantage plan and decide a few months later that you want to go back, you generally are not guaranteed the right to buy your old Medigap policy back at the same price — Medigap underwriting will likely apply, and in most states, an insurer can charge you more or decline you outright based on your health history. The exception is for beneficiaries who switch into MA for the first time within twelve months of becoming Medicare-eligible; they retain a trial-right back to Medigap. For everyone else, the move from Medigap to MA is reversible on paper but not always reversible in practice. We covered this in detail in our reporting on how Medigap underwriting has become a closing door for many 2026 enrollees.
How to Actually Make the Switch
Once you've decided to use the SEP, the mechanics are straightforward. You can enroll in the new 5-star plan directly through the Medicare Plan Finder at Medicare.gov, by calling 1-800-MEDICARE, or by calling the plan itself. You do not need to formally disenroll from your old plan — your enrollment in the new plan automatically triggers disenrollment from the old one. The new coverage starts the first day of the month after you enroll, with one exception: if you enroll on the very last day of a month, some plans still start coverage the following month rather than the same one. To avoid ambiguity, enroll at least a week before month-end.
Keep three records. The Medicare confirmation letter showing the new plan and effective date. The disenrollment notice (or absence of one) from your old plan. Any prior authorization or claim that crosses the transition date — those are the items most likely to generate billing confusion in the first month. If a claim is denied because the provider billed the wrong plan for the wrong date, that is fixable, but it is much easier to fix when you have the paperwork in front of you.
✅What This Means for You
- Look up your ZIP code on Medicare.gov today and filter for 5-star plans. If the list is empty, the SEP doesn't apply this year — but you have lost nothing by checking.
- If a 5-star plan is available, do not enroll on impulse. Confirm doctors, prescriptions, and pending procedures will all transfer cleanly before you use your one-time switch.
- Remember that the 5-Star SEP is one use per window. If you switch in July and a different 5-star plan appears in November, you cannot switch again under this SEP — you'd have to wait for the Annual Enrollment Period.
- Don't cancel a Medigap policy until you've checked whether you'd be eligible to get it back. For most beneficiaries beyond their first year on Medicare, that door has underwriting attached.
- If you're affected by a mid-year network change, a move, or a Medicaid eligibility change, ask 1-800-MEDICARE specifically whether your situation triggers a separate SEP — those are stacked on top of the 5-Star window, not in place of it.
