Medicare Open Enrollment runs from October 15 to December 7, 2025

Open Enrollment is the yearly window when you can change your Medicare coverage for the coming year. In 2025, that window opens on October 15 and closes on December 7. Any changes you make during this period take effect on January 1, 2026.

If you do not make a change during Open Enrollment, your current plan continues into 2026 with whatever premium, deductible, and coverage changes your plan has announced. Some people need to act during this window; others can stay put. The key is knowing which group you are in and what your options actually are.

Key Takeaways

  • Open Enrollment for 2025 runs October 15 through December 7, and changes take effect January 1, 2026.
  • You can switch between Original Medicare and Medicare Advantage, move to a different plan within the same type, or add or drop prescription drug coverage.
  • If you are happy with your current plan and it is not being discontinued, you do not have to do anything during Open Enrollment.
  • Your plan's costs, coverage, and pharmacy network may change for 2025 even if you stay in the same plan, so reviewing your options is worth the time.
  • If you miss the October 15 important date, you may not be able to change plans until the following year unless you have a may have access to life event.

What you can change during Open Enrollment

During the October 15 to December 7 window, you can switch from Original Medicare to a Medicare Advantage plan, or from Medicare Advantage back to Original Medicare. You can also move from one Medicare Advantage plan to another, or from one Medigap plan to a different Medigap plan if you have one.

If you have a prescription drug plan (Part D), you can drop it, switch to a different one, or add one if you do not currently have coverage. You can also make changes to your Medigap supplemental coverage. The one thing you cannot do is change your Part A (hospital) or Part B (medical) coverage itself — those are continuous once you are enrolled.

Keep in mind that switching plans means your doctors, hospitals, and pharmacies may change. Before you switch, check whether your current providers are in the new plan's network and whether your medications are covered at the same cost tier.

Why your current plan might change even if you do nothing

Insurance companies announce changes to their plans every year. Your current plan's monthly premium may go up, your deductible may increase, or your copayments for specific services might change. Pharmacies may be added to or removed from your plan's network, and the drugs covered under your prescription plan may shift.

Your plan may also be discontinued entirely in your area, in which case Medicare will send you a notice and you will be moved to a different plan automatically unless you choose a new one yourself during Open Enrollment. Even if your plan continues, the changes to cost and coverage can be significant enough to make a different plan a better fit for your needs and budget.

This is why many people review their options during Open Enrollment even if they plan to stay in the same plan — the costs and coverage may have shifted enough to make a switch worthwhile.

How to review your options before October 15

You do not have to wait until October 15 to start looking. Medicare.gov has a plan comparison tool where you can enter your current medications, doctors, and hospitals to see which plans cover them and at what cost. You can use this tool starting in September to get a sense of what is available in your area.

You can also call 1-800-MEDICARE to speak with a representative who can walk you through your options. Some local Area Agencies on Aging and senior centers offer free one-on-one counseling during this period as well. These counselors are trained to help you understand the differences between plans and can answer questions about coverage and costs.

Gather your current plan documents, a list of your medications, and the names of the doctors and hospitals you use most often. Having this information ready makes the comparison process much faster and more accurate.

What happens if you miss the December 7 important date

If Open Enrollment closes on December 7 and you have not made a change, your current plan continues into 2026. You will not be able to switch plans again until the next Open Enrollment period in October 2026, unless you experience a may have access to life event.

may have access to life events include losing employer coverage, moving to a different state, getting married or divorced, or having a significant change in income. If one of these happens to you, you may be able to change plans outside of Open Enrollment. You will need to contact Medicare within 60 days of the event to report it and request a Special Enrollment Period.

If you realize after December 7 that your plan no longer covers a medication you need or that your doctor is no longer in the network, you may have limited options until the next Open Enrollment. This is why reviewing your plan before the important date matters.

Important dates and reminders for 2025

Medicare typically mails plan information and notices in late September. You should receive your plan's 2025 coverage documents and any notices about changes to your current plan by early October. Read these carefully — they contain the specific details about what is changing for your plan.

Open Enrollment itself runs October 15 through December 7. Changes you make during this window take effect on January 1, 2026. If you are switching plans, your new plan will send you a welcome packet with details about how to use your coverage starting January 1.

Mark December 7 on your calendar. That is the last day to make changes for 2026 coverage. If you are on the fence about switching, do not wait until the last few days — the phone lines and online systems can be busy, and you want time to think through your decision.

Frequently Asked Questions

Can I change my mind after I switch plans during Open Enrollment?

Yes. If you switch plans during Open Enrollment and then change your mind, you can switch again before December 7. You can make as many changes as you want during the Open Enrollment window, but only your final choice will take effect on January 1.

What if my doctor or pharmacy is not in the new plan I want to join?

Contact the plan directly and ask whether your doctor or pharmacy is in-network. Some plans have exceptions or can add providers in certain cases. If your doctor is not in-network, ask whether they accept your new plan's out-of-network rates. If not, you may want to stay in your current plan or choose a different one.

Do I have to switch plans if my current plan is being discontinued?

No, but you must choose a new plan during Open Enrollment. If you do not, Medicare will automatically move you to a different plan. You can avoid this by selecting your own plan during the October 15 to December 7 window so you have control over where you are moved.

Can I switch from Original Medicare to Medicare Advantage and back again?

Yes, you can switch between Original Medicare and Medicare Advantage during Open Enrollment. However, if you switch from Original Medicare to Medicare Advantage and then want to go back to Original Medicare, you may need to go through underwriting for a Medigap plan, which could result in higher premiums or coverage denials based on your health.

What if I turn 65 during Open Enrollment?

If you turn 65 during Open Enrollment, you have your own enrollment window based on your birthday month, separate from the general Open Enrollment period. Contact Medicare or your local Social Security office to find out your specific enrollment dates.