Medicare Open Enrollment 2026: Dates, Plan Changes, and What to Review

Information checked: 2026-09-09 · Maintenance label: Annual fixed window

Medicare Open Enrollment runs 15 October to 7 December, and changes made during it take effect on 1 January.

It is the one window each year when almost everyone with Medicare can change almost anything, and it is also the window most people let pass. Plans change their drug lists, their pharmacy networks and their costs every year, so a plan that suited you last year may not this year.

This guide covers what you can change, the separate window that follows in January, and the specific things worth checking before you decide.

Key takeaway

Between 15 October and 7 December you can join, drop or switch a Medicare Advantage plan, move between Original Medicare and Medicare Advantage, and join or change a drug plan. Your enrollment request must be received by 7 December, and the change starts 1 January. Review your drug list and your pharmacy, not just the premium.

Table of contents

• What you can change, and when it starts
• The five things actually worth checking
• Read the notice your plan sends
• Comparing plans without being sold one
• If you miss 7 December
• Frequently asked questions
• Summary

Related guides

• Medicare Advantage 2027: How to Compare Drug, Provider, and Out-of-Pocket Changes — Comparing Medicare Advantage plans for next year
• Medicare Part D Deductible 2027: Costs, Coverage Stages, and Plan Checks — What changes in your drug plan costs
• Medicare Part B Premium 2027: When the Amount Is Announced and How to Check It — The premium and deductible figures behind the decision

What you can change, and when it starts

Period	Dates	What it allows	Effective
Open Enrollment	15 October to 7 December	Join, drop or switch a Medicare Advantage plan; move between Original Medicare and Medicare Advantage; join or change a drug plan	1 January
Medicare Advantage Open Enrollment	1 January to 31 March	If you are already in a Medicare Advantage plan, switch to another or return to Original Medicare	First of the month after the plan receives the request
Initial Enrollment	3 months before to 3 months after first becoming eligible	Join any plan	Varies with when you request it

The January window is narrower than it looks. It is only for people already enrolled in a Medicare Advantage plan, and it allows one change.

Compare with your own drug listMedicare Plan Finder ›The official comparison tool. Enter your prescriptions and pharmacy to see what each plan actually costs you, not the advertised premium.

The five things actually worth checking

1. Your drug list. Plans change their covered drug lists annually. A drug covered this year may move tier or drop off entirely.
2. Your pharmacy. Preferred pharmacy networks change, and the same plan can charge materially different amounts at different pharmacies.
3. Your doctors and hospitals. Medicare Advantage networks change. Confirm with the provider's office, not only with the plan directory.
4. The out-of-pocket maximum, if you are in Medicare Advantage. The premium is the smaller half of the story.
5. Prior authorisation rules for treatments you actually use.

Comparing on monthly premium alone is how people end up worse off after switching. The premium is the one number that is easy to compare, which is exactly why it is over-weighted.

Read the notice your plan sends

Before Open Enrollment, plans send an annual notice describing what is changing for the coming year. It is the single most useful document you will receive, and it arrives looking like junk mail.

Find the sections on the drug list, cost sharing, and network. If nothing you rely on has changed, doing nothing is a legitimate decision. If something has, that is your prompt to compare.

Comparing plans without being sold one

Use the official Medicare Plan Finder and enter your actual prescriptions, doses and pharmacy. It calculates a total estimated annual cost rather than showing a premium in isolation.

For one-to-one help, every state has a State Health Insurance Assistance Program offering free counselling. Counsellors there are not paid commission on plan sales, which is not true of every source of Medicare advice you will encounter this autumn.

Free one-to-one helpState Health Insurance Assistance Program ›Free, unbiased Medicare counselling in every state. Counsellors are not paid commission on plan sales.

If you miss 7 December

If you are in a Medicare Advantage plan, the 1 January to 31 March window lets you switch to another Medicare Advantage plan or return to Original Medicare, effective the first of the month after your request is received.

Outside those windows, changes generally require a Special Enrollment Period, which depends on specific circumstances such as moving out of your plan's service area or your plan leaving Medicare. Do not assume one applies; confirm it.

Frequently asked questions

What are the exact dates?

15 October to 7 December, with changes effective 1 January. The request must be received by 7 December.

If I do nothing, what happens?

You generally stay in your current plan under next year's terms, which may differ from this year's. That is why the annual notice matters.

Can I change again in January?

Only if you are already in a Medicare Advantage plan. The 1 January to 31 March window lets you switch plans or return to Original Medicare.

Does switching plans affect my doctors?

It can. Medicare Advantage networks change annually, so confirm your providers with their own offices before switching.

Where can I get unbiased help?

Your State Health Insurance Assistance Program offers free counselling and does not earn commission on plan enrollments.

Summary

Two dates carry the whole thing: 7 December to act, 1 January for the change to start.

Check the drug list, the pharmacy and the provider network against your own use before comparing premiums. The premium is the easiest number to compare and the least likely to decide your actual annual cost.