Yes, you must take action during the annual enrollment period, but the action depends on your plan type

Original Medicare (Part A and Part B) does not require you to renew each year — once you are enrolled, coverage continues automatically as long as you pay your Part B premium. However, if you have a Medicare Advantage plan (Part C) or prescription drug coverage (Part D), you must review your coverage during the annual enrollment period and actively choose to keep your current plan or switch to a different one. If you do nothing during this window, your plan may change or you may lose coverage.

The annual enrollment period runs from October 15 to December 7 each year. During this time, you can change plans, add or drop coverage, or stay where you are. The changes take effect January 1 of the following year. Missing this window means you are locked into your current plan for the entire next year, unless you experience a may have access to life event.

Key Takeaways

  • Original Medicare (Part A and Part B) renews automatically each year without any action from you, as long as you pay your Part B premium.
  • Medicare Advantage and Part D prescription drug plans require you to actively choose during the annual enrollment period each October through December, or your coverage may change.
  • The annual enrollment period is October 15 to December 7, and changes take effect January 1.
  • If you miss the enrollment period, you cannot switch plans until the next year unless you have a may have access to life event such as losing employer coverage or moving to a new state.
  • Medicare sends you a notice in advance of the enrollment period listing plan changes, premium increases, and coverage updates for your current plan.

How Original Medicare renewal works

If you have Original Medicare (Part A hospital insurance and Part B medical insurance), your coverage renews automatically. You do not need to contact Medicare, fill out a form, or take any action. As long as you continue to pay your Part B premium — which is usually deducted from your Social Security check — your coverage stays in place.

The only time you need to act is if you want to make a change: drop Part B, add Medigap supplemental coverage, or switch to a Medicare Advantage plan. These changes can happen during the annual enrollment period or during other specific windows depending on your situation.

How Medicare Advantage and Part D renewal works

Medicare Advantage plans and Part D prescription drug plans operate differently. These are run by private insurance companies under contract with Medicare, and they can change their coverage, costs, and networks every year. Your plan may add or remove doctors from its network, raise premiums, change copays, or alter which drugs it covers.

During the annual enrollment period, you receive a notice from your plan listing these changes. You then decide whether to stay with your current plan or switch to a different one. If you take no action, you are automatically re-enrolled in your current plan for the next year. However, if your plan is being discontinued, Medicare will assign you to a new plan automatically — you do not get to choose which one.

If you have both a Medicare Advantage plan and a separate Part D prescription drug plan, you can change either one independently during the enrollment period. You can also switch from Medicare Advantage back to Original Medicare and add a Medigap policy, though this has different timing rules.

The annual enrollment period and what you need to do

The annual enrollment period runs from October 15 to December 7 each year. During this time, you can review your current coverage, compare other plans, and make changes. The easiest way to compare plans is through Medicare.gov, where you can enter your current doctors and medications to see which plans cover them and what your out-of-pocket costs would be.

You do not have to make a change during this period. If your current plan still meets your needs and costs have not risen significantly, you can do nothing and stay enrolled. However, if your plan is discontinuing, if your doctor is leaving the network, or if your medications are no longer covered at the same cost, you should act during this window.

Changes you make during the annual enrollment period take effect on January 1 of the next year. If you switch plans, your old plan coverage ends on December 31 and your new plan begins on January 1.

What happens if you miss the enrollment period

If the annual enrollment period ends and you have not made a change, you are locked into your current plan for the entire next year. You cannot switch Medicare Advantage plans, change your Part D coverage, or make other plan changes until the next October 15.

The only exception is if you experience a may have access to life event. These include losing employer coverage, moving to a new state or county, getting married or divorced, becoming a U.S. citizen, or having a significant change in income. If any of these happen, you may be able to make changes outside the annual enrollment period. You typically have 60 days from the event to contact Medicare and request a change.

If you realize after January 1 that your plan no longer works for you — your doctor left the network, a medication is no longer covered, or costs are too high — you will have to wait until the next October 15 to switch, unless you can document a may have access to event.

How to review your coverage before the enrollment period

Medicare sends you a notice in the mail before the annual enrollment period begins, usually in September. This notice lists any changes to your current plan: premium increases, changes to copays and deductibles, changes to the network of doctors and hospitals, and changes to which drugs are covered. Read this notice carefully, because it tells you whether your plan is changing in ways that matter to you.

You should also make a list of your current doctors and medications before you start comparing plans. When you use the plan comparison tool on Medicare.gov, you can enter this information to see which plans cover your doctors and drugs and what you would pay out of pocket. This takes 15 to 20 minutes but can save you hundreds of dollars a year.

If you need help understanding your notice or comparing plans, you can contact your State Health Insurance information Program (SHIP), which offers free counseling. You can find your local SHIP by calling 1-877-839-2675 or visiting shiptalk.org.

Special rules for switching from Medicare Advantage back to Original Medicare

If you have a Medicare Advantage plan and want to switch back to Original Medicare, you can do so during the annual enrollment period. However, if you want to add a Medigap supplemental policy at the same time, the timing matters. Medigap policies have their own underwriting rules, and some companies will not sell you a policy if you are switching from Medicare Advantage outside of certain windows.

The safest approach is to switch to Original Medicare during the annual enrollment period (October 15 to December 7) and explore for Medigap coverage at the same time, so both take effect on January 1. If you switch to Original Medicare at a different time of year, you may face higher Medigap premiums or coverage exclusions. Contact a SHIP counselor before making this switch to understand your options.

Frequently Asked Questions

Do I have to do anything if I want to keep my current Medicare plan?

If you have Original Medicare, no action is required — your coverage continues automatically. If you have a Medicare Advantage or Part D plan and want to keep it, you do not have to take action, but you should review the notice Medicare sends you to understand any changes to costs or coverage. If you do nothing, you will be automatically re-enrolled in your current plan on January 1.

What if my Medicare Advantage plan is being discontinued?

If your plan is discontinuing, Medicare will automatically assign you to a different plan on January 1. You will receive notice of this reassignment in advance. You can choose a different plan during the annual enrollment period instead of accepting the automatic assignment, so you should act rather than wait.

Can I change my Medicare coverage in the middle of the year?

Generally, no. Changes made during the annual enrollment period take effect January 1. If you experience a may have access to life event — such as losing employer coverage, moving, getting married, or becoming a citizen — you may be able to make changes within 60 days of the event. Contact Medicare at 1-800-MEDICARE to report the event and ask whether you can make changes.

What if I turn 65 during the year?

When you first become may be able to access for Medicare at 65, you have a seven-month initial enrollment period centered on your birth month. During this time, you can enroll in Original Medicare, Medicare Advantage, and Part D. After this period ends, you are subject to the annual enrollment period like everyone else.

How do I know if my doctor is still in my plan's network?

Your plan's annual notice will list network changes. You can also search for your doctor on your plan's website or call the plan's customer service number to confirm they are still in network for the next year. If your doctor is leaving the network, this is a good reason to compare other plans during the annual enrollment period.