What the window is for
The fall window, October 15 to December 7, is when most people choose. The Medicare Advantage Open Enrollment Period is the correction window for people who chose an Advantage plan, or stayed in one, and discovered in January that it does not fit.
It is narrow on purpose. You get one change between January 1 and March 31. The new coverage starts on the first day of the month after the new plan receives your request, so a change made on January 20 starts February 1.
Someone who joined an Advantage plan when they first got Medicare has a separate window as well: within the first three months of having Part A and Part B, they can change plans or return to Original Medicare. If that describes you, you may have more room than this page suggests.
What it allows, and what it does not
| You want to | Allowed January 1 to March 31? |
|---|---|
| Switch from one Advantage plan to another, with or without drug coverage | Yes, once |
| Leave the Advantage plan for Original Medicare and join a stand-alone drug plan | Yes, once |
| Move from Original Medicare into an Advantage plan | No |
| Switch between stand-alone drug plans while on Original Medicare | No |
| Make a second change after using the first | No, unless another special enrollment period applies |
One mechanical detail matters. When you leave an Advantage plan by joining a stand-alone drug plan, that enrollment ends the Advantage plan automatically. You do not need a separate cancellation, and you should not leave yourself without drug coverage by cancelling first.
January’s usual surprises
The notice that arrived in September described the plan. January shows it in use. The common discoveries:
- A prescription costs more than expected, because it moved to a higher tier or now needs prior authorization or step therapy.
- A specialist or a hospital is out of network, or the office no longer takes the plan.
- A service needs approval first, and the approval takes time. Since 2026, Advantage plans must decide urgent requests within 72 hours and standard ones within 7 days, and give a specific reason for a denial.
Before using your one change, check whether the problem can be fixed inside the plan: a formulary exception for a drug, an appeal of a denial, a transition fill for a medication you were already taking. When a drug is denied. If it cannot, this window is the remedy.
Going back to Original Medicare in New York
Leaving an Advantage plan is risky in most states because the supplement that makes Original Medicare affordable may no longer be sold to you without health questions. New York removed that risk: insurers writing Medicare supplements here must accept an application at any time of year and may not refuse or charge more because of health. Premiums are community rated.
- Apply for the supplement first, with a start date on the first day of the month after your request. An insurer may sell it to you while you are still in the Advantage plan because you are switching back.
- Join a stand-alone drug plan in the same window. That enrollment moves you out of the Advantage plan.
- Ask about a waiting period. A new supplement can exclude pre-existing conditions for up to six months, reduced or waived by earlier coverage, and time in an Advantage plan counts.
- Check EPIC if you are 65 or older: New York’s drug program sits on top of the Part D plan. How EPIC works.
- Tell your doctors which cards to bill from the start date.
The full Advantage-or-Original comparison.
Other windows that may apply
If you have Medicaid or receive Extra Help, you can make certain coverage changes once a calendar month, effective the first day of the next month, so you are not limited to this window. If a plan rated 5 stars exists in your area, a special enrollment period lets you switch into it once between December 8 and November 30. And if your plan left at the end of the year, your special window runs to the end of February. If your plan is leaving.
Free, objective help deciding which window fits: HIICAP, New York’s Medicare counseling program, at 1-800-701-0501.
Questions people ask
When is the Medicare Advantage Open Enrollment Period?
January 1 to March 31, 2027, for people who are already in a Medicare Advantage plan.
How many changes can I make?
One. It starts the first day of the month after the new plan receives your request.
Can I use it to join an Advantage plan from Original Medicare?
No. That move is only possible in the fall window, October 15 to December 7, or with a special enrollment period.
If I go back to Original Medicare, can I get a supplement in New York?
Yes. New York insurers must accept supplement applications in any month and may not charge more because of your health. A waiting period of up to six months for pre-existing conditions can apply, reduced by earlier coverage, including the Advantage plan.
Do I need to cancel my Advantage plan myself?
Not if you are joining a stand-alone drug plan: that enrollment ends the Advantage plan automatically. Do not cancel first and leave yourself without drug coverage.
Who can help me decide without selling me a plan?
HIICAP, New York’s free Medicare counseling program, at 1-800-701-0501.
Sources
- Medicare & You 2027 — the official handbook (checked 2026-09-29)
- Medicare.gov — joining a plan (checked 2026-09-29)
- NYS Department of Financial Services — protections for Medicare beneficiaries residing in New York (checked 2026-09-29)
- Medicare.gov — illegal Medigap practices (checked 2026-09-29)
More in The Health Coverage Calendar for New Yorkers, October 2026 to April 2027
- Missed Medicare Part B? The January Window, and the Route Around It — Missed your first chance at Part B? The General Enrollment Period runs January 1 to March 31. When coverage starts, what the penalty costs, and the savings-program route.
- What Resets on January 1, 2027, and the First-Week Checklist — Deductibles, out-of-pocket counters, drug lists and networks start over on January 1. What else changes in 2027 in New York, and what to check in the first week.
- Form 1095-A From NY State of Health: What It Is and Why the 2026 Return Is Different — Had a marketplace plan in 2026? Form 1095-A arrives by January 31 and feeds Form 8962. Why the 2026 return is the first with no cap on repaying the credit.
This page explains how the system works. It is not medical advice. More.