Medicare lets you change plans during specific windows each year, not whenever you want

You can change your Medicare plan during Open Enrollment (October 15 to December 7 each year), when any change takes effect January 1. You can also switch plans during Medicare Advantage Open Enrollment (January 1 to March 31), which applies only if you already have a Medicare Advantage plan. Outside these windows, you need a may have access to life event — moving to a new state, losing employer coverage, getting married, or a similar change — to switch before the next Open Enrollment period.

The rules differ depending on whether you have Original Medicare (Parts A and B), a Medicare Advantage plan (Part C), or a prescription drug plan (Part D). Knowing which window applies to you and what counts as a may have access to event can save you months of waiting or prevent you from being locked into a plan you no longer want.

Key Takeaways

  • Open Enrollment runs October 15 to December 7 each year, and changes take effect January 1 of the following year.
  • If you have a Medicare Advantage plan, you can also switch during January 1 to March 31 without needing a reason.
  • Outside these windows, you must have a may have access to life event (moving, losing coverage, marriage, or similar) to change plans.
  • You report may have access to events to Medicare within 60 days to get a Special Enrollment Period, usually lasting two months.
  • If you miss a important date and have no may have access to event, you are locked into your current plan until the next Open Enrollment.

Open Enrollment: The main window for all Medicare changes

Open Enrollment is the annual period when you can change any Medicare plan without a reason. It runs from October 15 through December 7 each year. Any plan change you make during this window takes effect on January 1 of the next year. You can switch from Original Medicare to a Medicare Advantage plan, from Medicare Advantage back to Original Medicare, change from one Medicare Advantage plan to another, or change your prescription drug plan (Part D).

You do not have to change anything during Open Enrollment — if you are happy with your current plan, you can do nothing and your coverage continues. But if you want to switch, this is the only time you can do so without proving a reason. Many people use this window to review their plan's costs, coverage, and network of doctors for the coming year, especially if their health needs or medications have changed.

To make a change during Open Enrollment, you can call Medicare at 1-800-MEDICARE, visit Medicare.gov, or work with a licensed insurance agent. You have until December 7 to make your choice; changes submitted after that date will not take effect until the following year's Open Enrollment.

Medicare Advantage Open Enrollment: A second window if you already have a Medicare Advantage plan

If you are already enrolled in a Medicare Advantage plan, you get a second chance to switch plans during Medicare Advantage Open Enrollment, which runs January 1 through March 31 each year. During this period, you can switch to a different Medicare Advantage plan or go back to Original Medicare — again, without needing a reason. This window exists only for people already in Medicare Advantage; if you have Original Medicare, this period does not explore to you.

The catch is that any change made during this window takes effect the first day of the following month. If you switch on January 15, your new plan starts February 1. If you switch on March 20, your new plan starts April 1. This is different from Open Enrollment, where all changes take effect on January 1 regardless of when you submit them.

This second window is useful if you enrolled in a Medicare Advantage plan during Open Enrollment but realized it was not the right fit — perhaps the doctor you wanted is not in the network, or the plan costs more than you expected. You have until March 31 to make a change before you are locked in again until the next Open Enrollment.

may have access to life events that let you change plans outside the enrollment windows

If you miss Open Enrollment or Medicare Advantage Open Enrollment, you can still change plans if you have a may have access to life event. Medicare recognizes these situations as reasons to switch outside the normal windows. The most common may have access to events are: moving to a new state or county, losing health coverage (such as employer coverage or Medicaid), getting married or divorced, becoming a U.S. citizen or gaining lawful permanent resident status, or a change in your income that affects your costs.

Other may have access to events include being a victim of domestic violence, having a family member move into or out of your home, or a change in your living situation (such as moving from a nursing home to your own home). If your plan is being discontinued or your doctor is leaving the plan's network, that also counts. The full list is on Medicare.gov, and you should check it if you think your situation might may have access to.

When you have a may have access to event, you must report it to Medicare within 60 days of the event. You do this by calling 1-800-MEDICARE, visiting Medicare.gov, or contacting your plan directly. Medicare will give you a Special Enrollment Period, usually lasting two months, during which you can change plans. Any change you make during a Special Enrollment Period takes effect on the first day of the month after you enroll.

What counts as a may have access to event and what does not

Moving to a new state or county is a clear may have access to event — your current plan may not serve your new location, and you need time to find a new one. Losing employer coverage, Medicaid, or other health insurance also qualifies. If your employer stops offering health benefits or you retire and lose coverage, you have 60 days to report this and get a Special Enrollment Period.

Changes in your household also count: getting married, divorcing, or having a family member move in or out of your home. If you become a U.S. citizen or gain lawful permanent resident status, that qualifies. A significant change in your income — such as losing a job or receiving a large inheritance — can also trigger a Special Enrollment Period, because it may affect whether you pay extra premiums or may have access to for cost-sharing help.

What does not count: changing your mind about your plan, wanting to switch to a plan with a lower premium, or deciding you do not like your doctor anymore (unless the doctor is actually leaving the plan). Dissatisfaction with your plan is not a may have access to event. Neither is a minor change in your health status. You must have a concrete life change, not just a preference change.

How to report a may have access to event and get a Special Enrollment Period

Once you have a may have access to event, you have 60 days from the date of the event to tell Medicare. The fastest way is to call 1-800-MEDICARE and explain what happened. Have your Medicare card and the date of the event ready. You can also report it online at Medicare.gov by logging into your account and selecting the option to report a life event, or you can contact your current plan directly and ask them to process the change.

When you report the event, Medicare will verify it and send you a letter confirming your Special Enrollment Period. This letter will tell you the exact dates during which you can change plans — usually two months from the date Medicare processes your request. You then have until the last day of that period to choose a new plan. If you do not choose a plan by the important date, your Special Enrollment Period ends and you are locked into your current plan until the next Open Enrollment.

Keep the confirmation letter Medicare sends you. If there is a dispute later about whether you were allowed to change plans, this letter is your proof. If you miss the 60-day important date to report the event, you lose the right to a Special Enrollment Period and must wait for the next Open Enrollment.

What happens if you miss all the important date

If you do not change your plan during Open Enrollment, Medicare Advantage Open Enrollment, or a Special Enrollment Period, you are locked into your current plan for the rest of the year. You cannot switch until the next Open Enrollment in October, unless another may have access to event happens in the meantime.

This is why it is important to mark the dates on your calendar: Open Enrollment is October 15 to December 7, and Medicare Advantage Open Enrollment is January 1 to March 31. If you have a may have access to event, report it within 60 days. If you wait until August and realize you want a different plan, you will have to stay in your current plan for at least two more months until Open Enrollment begins.

The one exception is if your plan is being discontinued by the insurance company. In that case, Medicare will automatically move you to another plan or give you a Special Enrollment Period to choose one yourself. You will receive a letter from your plan explaining what is happening and your options.

Frequently Asked Questions

Can I change my plan if I just realized I chose the wrong one in October?

If you are in a Medicare Advantage plan, you can switch during January 1 to March 31 without a reason. If you have Original Medicare or a Part D plan, you must wait until the next Open Enrollment (October 15 to December 7) unless you have a may have access to life event. If you have a may have access to event, call 1-800-MEDICARE within 60 days to report it.

What if I move to a different state after Open Enrollment?

Moving to a new state is a may have access to event. You have 60 days from the date you move to call 1-800-MEDICARE and report it. Medicare will give you a Special Enrollment Period, usually lasting two months, during which you can switch to a plan that covers your new location. Your new plan takes effect the first day of the month after you enroll.

If I lose my job and my employer health coverage, how long do I have to switch to Medicare?

Losing employer coverage is a may have access to event. You have 60 days from the date your coverage ends to report it to Medicare. Once you report it, you get a Special Enrollment Period to change your Medicare plan. You do not have to wait until Open Enrollment.

What if my doctor leaves my Medicare plan's network?

If your doctor is leaving the plan's network, that is a may have access to event. Contact your plan or call 1-800-MEDICARE to report it and ask for a Special Enrollment Period. You will have time to switch to a plan that includes your doctor before the change takes effect.

Can I change my plan more than once during Open Enrollment?

Yes, you can change your plan multiple times during Open Enrollment (October 15 to December 7), but only your last change will take effect. If you change your mind, you can switch again before December 7. After December 7, your final choice is locked in and takes effect January 1.