What Changes During Medicare Open Enrollment 2027
Medicare Open Enrollment runs October 15 through December 7, and the choices you make during it take effect January 1, 2027. That’s the short answer. The longer answer is that two different kinds of change happen in this window, and most people only think about one of them.
The first kind is the change you make — switching plans, dropping a plan, adding drug coverage. The second kind is the change your plan makes to itself, which happens whether you open the envelope or not. If you do nothing at all during Open Enrollment, your coverage continues automatically, but it continues on the plan’s 2027 terms, not its 2026 terms. That second kind is the one that surprises people in February.
What you can change
Your options depend on the coverage you have now. According to Medicare.gov, during Open Enrollment you can:
- Join, drop, or switch to another Medicare Advantage Plan, with or without drug coverage
- Add or drop drug coverage on a Medicare Advantage Plan
- Join, drop, or switch a Medicare drug plan if you’re in Original Medicare
- Switch from Original Medicare to a Medicare Advantage Plan, or from a Medicare Advantage Plan back to Original Medicare
The plan has to receive your enrollment request by December 7. That’s a receipt deadline, not a postmark deadline. If you’re mailing a paper form, that distinction matters.
What changes without asking you
Medicare costs, benefits, provider networks, and drug formularies can all change each year. Your plan is required to tell you about its changes in a document called the Annual Notice of Change, or ANOC, which arrives in September.
The ANOC is the single most useful piece of mail you’ll get all fall, and it’s also the one most likely to get thrown out, because it shows up in the same week as a pile of plan advertising. It’s worth learning to recognize. It comes from your current plan, not from a company trying to sell you something, and it lays out side by side what you pay now and what you’ll pay in January. If September ends and you haven’t received one, contact your plan and ask for it.
Four things in the ANOC deserve a careful read:
- The premium and deductible. These are the numbers people check.
- The drug list. A drug can move to a higher cost tier, pick up a prior authorization requirement, or come off the list entirely.
- The provider network. Your doctor being in-network this year does not guarantee anything about next year.
- The extra benefits. Dental, vision, hearing, and over-the-counter allowances are the parts of a Medicare Advantage plan that change most freely, because they aren’t standardized by Medicare.
The calendar
CMS lays the fall out in four dates:
| Date | What happens |
|---|---|
| October 1 | Review the notices from your current plan; plan information for the new year becomes available |
| October 15 | Open Enrollment begins |
| December 7 | Open Enrollment ends — your plan must have your enrollment form |
| January 1 | New coverage begins, and any changes to your existing plan take effect |
What’s specifically different heading into 2027
CMS finalized its Contract Year 2027 rules for Medicare Advantage and Part D in April 2026. A few of the changes will show up in what you see this fall.
Star Ratings are being recalculated on a shorter list of measures. CMS is removing eleven measures focused on administrative processes and on areas where plans all perform about the same, on the reasoning that those measures didn’t help anyone tell plans apart. CMS is also not implementing the Excellent Health Outcomes for All reward for 2027 Star Ratings. The practical effect: a plan’s star rating may move up or down partly because the scoring changed, not because the plan’s care changed. Treat a one-star swing as a reason to look closer, not as a verdict.
Plans no longer have to mail you a mid-year reminder about unused supplemental benefits. CMS rescinded that requirement. If your plan includes a dental allowance or an over-the-counter card, nobody is obligated to tell you in July that you haven’t touched it.
Supplemental benefit debit cards are getting tighter rules. CMS is requiring that these cards be electronically linked to plan-covered items and services, with eligibility verified at the register, and that the cards be limited to the specific plan year. Balances are tied to that year — they are not a savings account.
On the drug side, the coverage gap phase is gone for good. The Inflation Reduction Act eliminated the old “donut hole” and capped what you pay out of pocket for covered Part D drugs each year. CMS previously implemented this through year-by-year program instructions; the 2027 rule writes it into regulation permanently, including no cost sharing once you reach the catastrophic phase.
One thing that is not available yet: the 2027 Part B premium and deductible. CMS announces those in the fall, so anyone quoting you a 2027 Part B figure this summer is guessing. The 2027 Part D amounts for your specific plan will be in your ANOC and on Medicare’s Plan Finder in October.
Where people go wrong
Treating January as a do-over. There is a second window — Medicare Advantage Open Enrollment, January 1 through March 31 — but it’s narrower than people assume. If you’re in a Medicare Advantage plan on January 1, you get one chance to switch to a different Medicare Advantage plan or go back to Original Medicare. You cannot use it to move from Original Medicare into a Medicare Advantage plan, and if you’re on Original Medicare you can’t use it to pick up a standalone drug plan. Coverage from a January-through-March change starts the first day of the month after your plan gets the form, so you’d be living with the old plan in the meantime.
Assuming Medigap works like a revolving door. If you have a Medicare Supplement (Medigap) policy and you join a Medicare Advantage plan, you may decide to drop the Medigap policy. Getting it back later is a different matter. Whether you can — and at what price, and with what health questions — depends on your state’s Medigap rules and your particular situation. In much of the country this is closer to a one-way door than a switch. Understand your state’s rules before you drop a Medigap policy, not after.
Comparing on premium alone. A lower premium with a different drug tier structure, a smaller network, or a higher out-of-pocket maximum isn’t automatically cheaper for you. What matters is your total expected cost given your prescriptions and your doctors, which is what Medicare’s Plan Finder is built to estimate.
Doing nothing on purpose but not on evidence. Staying put is a perfectly reasonable decision. Staying put because you didn’t read the ANOC isn’t the same decision — it just looks like it until January.
If you want help sorting through it, your State Health Insurance Assistance Program offers free counseling, and 1-800-MEDICARE is staffed around the clock.
Sources: Medicare.gov, “Open Enrollment” (medicare.gov/health-drug-plans/open-enrollment); Medicare.gov, “Plan Annual Notice of Change (ANOC)”; CMS Product No. 11220, “Your Yearly Medicare Review”; CMS Fact Sheet, “Contract Year 2027 Medicare Advantage and Part D Final Rule,” April 2, 2026 (cms.gov); CMS, “Medicare Beneficiaries to See Simpler and More Flexible Plan Choices, Better Drug Coverage, Higher Quality and Lower Costs in 2027,” April 2, 2026 (cms.gov).
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This content is for general educational purposes and is not a complete description of benefits. Contact the plan for more information. Medicare Compare Agency, 2201 Providence Park, #150, Birmingham, Alabama 35242.