Medicare open enrollment for 2027 runs from 15 October to 7 December 2026. Those are the only eight weeks in which almost everyone on Medicare can change their coverage for the following year — and missing the deadline means waiting another twelve months with whatever plan you have now, even if the premium has jumped.
This guide covers the four separate enrolment windows that people constantly confuse, what is changing for 2027, how to compare plans without being sold something, and the specific deadlines that arrive before 7 December.
The Four Medicare Enrolment Periods
| Period | Dates | Who it is for | What you can do |
|---|---|---|---|
| Annual Open Enrollment | 15 Oct – 7 Dec 2026 | Everyone with Medicare | Change Part D, switch Advantage ↔ Original, join or drop Advantage |
| Medicare Advantage OEP | 1 Jan – 31 Mar 2027 | Advantage members only | One change only: switch plan or return to Original Medicare (cannot add Part D at this stage) |
| Initial Enrolment Period | 7 months around your 65th birthday | People new to Medicare | First enrolment — 3 months before, the birthday month, and 3 after |
| Special Enrolment Period | Varies | Qualifying life events | Move house, lose employer coverage, plan exits the market, dual eligibility |
What Is Changing for 2027
| Item | 2026 | 2027 | Status |
|---|---|---|---|
| Standard Part B premium | $202.90 | $209.50 | Trustees projection |
| Part B annual deductible | $283 | About $292 | Trustees projection |
| Part D out-of-pocket cap | $2,100 | $2,400 | Confirmed |
| Social Security COLA | 2.8% | 3.6% | Confirmed |
The Part D cap rise from $2,100 to $2,400 matters more than it looks. If you take several expensive prescriptions, that $300 is the maximum you can be asked to pay out of pocket at the pharmacy counter in a calendar year — and it applies only when your drugs are on the plan’s formulary. A cheap premium with a bad formulary can still cost you more than a mid-priced plan with everything covered.
The Part B premium figure is a projection until CMS publishes the official amount, normally in November. Our Medicare Part B premium 2027 guide tracks that announcement, and the 2027 COLA breakdown explains how the premium is deducted before you see your increase.
How to Compare Plans Without Getting Sold Something
Open enrollment season generates a flood of advertising. Three rules keep you safe:
- Use the official plan finder. Put your prescriptions, dosages and pharmacy into Medicare’s own plan finder. It produces a total estimated annual cost per plan — premium plus drug costs plus copays — which advertising never does.
- Ignore the “your plan is being discontinued” phone call. Scam callers use that line every year. Check the claim yourself with your plan, in writing.
- Understand the two structures. Original Medicare (Parts A and B) plus a standalone Part D and possibly Medigap is one route. Medicare Advantage (Part C) bundles everything but restricts networks and requires prior authorisation for much care. Neither is universally better.
| Feature | Original Medicare + Part D | Medicare Advantage |
|---|---|---|
| Doctor choice | Any provider that accepts Medicare nationwide | Network-based; out-of-network costs more or is not covered |
| Referrals needed | No | Often yes, especially for specialists |
| Prior authorisation | Rare | Common |
| Monthly premium | Part B + Part D + optional Medigap | Usually low or $0 on top of Part B |
| Extra benefits | None beyond A and B | Often dental, vision, hearing, fitness |
| Best for | People who travel, or see many specialists | People who want one card and a predictable premium |
The Medigap Trap
If you are on Original Medicare, Medigap (supplemental insurance) covers much of the 20% coinsurance. The trap is the guaranteed-issue window: you have a one-time six-month window that starts the month you are 65 and enrolled in Part B, during which an insurer cannot refuse you or charge more for health reasons.
After that window closes, in most states, Medigap insurers can underwrite you. So if you leave Original Medicare for Advantage and later want to come back to Medigap, you may be refused or charged a much higher premium because of your health history. That single decision — leaving Original Medicare — is often irreversible in practice, even though it looks reversible on paper.
A Practical Open Enrollment Checklist
- Gather your prescriptions — exact drug names, doses, and frequency.
- Wait for your Annual Notice of Change. It arrives by 30 September and lists exactly what your current plan is changing for 2027: premium, deductible, copays and formulary removals.
- Run the official plan finder with your real drugs and pharmacy.
- Check that your doctors are still in network — and recheck every year, because networks change.
- Confirm the drug formulary in writing before enrolling, not after.
- Enrol by 7 December 2026, and keep the confirmation number.
- Verify in January 2027 that the new premium is the one you expected — the first deduction shows it.
Frequently Asked Questions
When is Medicare open enrollment for 2027?
15 October to 7 December 2026. Coverage chosen during this window starts on 1 January 2027.
Can I change my Medicare Advantage plan in January?
Yes, but only once, and only between 1 January and 31 March 2027. You may switch to another Advantage plan or return to Original Medicare, but you cannot add a standalone Part D plan during that window.
What happens if I miss 7 December?
You stay on your current 2026 plan for 2027, whatever its new premium and benefits are. The next general chance to change is the following October, unless you qualify for a Special Enrolment Period.
Is the $209.50 Part B premium final?
No. It is the Medicare Trustees’ projection from their 2026 report. CMS normally confirms the official amount in November, and the final figure can differ by a few dollars.
Do I need to do anything if I am happy with my plan?
You do not have to act. But you should still read the Annual Notice of Change, because an unchanged premium does not mean an unchanged plan. Formularies and networks change quietly every year.
Bottom Line
15 October to 7 December 2026 is the window. Confirm your drugs, check your doctors, run the official plan finder, and decide before 7 December. Then watch for the January deduction to confirm the new Part B premium of about $209.50. The people who lose money in this system are rarely the ones who chose badly — they are the ones who never chose at all.
