What Open Enrollment Period Means for Medicare

Open Enrollment Period is the window of time each year when you can join a Medicare plan, switch plans, or drop coverage without penalty. For most people, this runs from October 15 through December 7 each year. During these dates, Medicare Advantage plans and prescription drug plans (Part D) must accept anyone who applies, regardless of health status.

Outside this window, you generally cannot change plans unless you have a may have access to life event — a move, loss of employer coverage, marriage, divorce, or death in the family. If you try to switch plans at the wrong time without a may have access to event, you will have to wait until the next Open Enrollment Period, which means staying in a plan that may not meet your needs for months.

The stakes matter because plan costs, drug coverage, and doctor networks change every year. A plan that worked well in 2023 might have dropped your pharmacy, raised your copay, or added a specialist to its network in 2024. Open Enrollment is your annual chance to review what changed and move to something better.

Key Takeaways

  • Open Enrollment runs October 15 through December 7 each year, and any changes you make take effect January 1.
  • You can only switch Medicare Advantage or Part D plans during this period unless you have a may have access to life event like a move or loss of coverage.
  • Medicare sends you a notice in September or October listing plan changes in your area, including new copays, deductibles, and drug coverage.
  • If you miss Open Enrollment and have no may have access to event, you are locked into your current plan until the next October.
  • Special Enrollment Periods allow you to change plans outside the regular window if you move, lose employer coverage, or experience other specific life changes.

The Dates and What Happens During Open Enrollment

Open Enrollment for Medicare runs from October 15 through December 7 every year. Any plan changes you make during this window take effect on January 1 of the following year. This gives you about seven weeks to review your options, compare plans, and make a switch if you want to.

You do not have to do anything during Open Enrollment if you are happy with your current plan. But if you want to change plans, you must act before December 7. After that date, you cannot switch until the next October, with rare exceptions for may have access to events.

The timing matters because Medicare sends you notices starting in September. Your current plan will mail you information about what is changing — copays, deductibles, which drugs are covered, which doctors are in the network. Read these notices carefully, because they tell you whether your plan is still a good fit.

How to Find Out What Changed in Your Plan

Every September or early October, your Medicare Advantage plan and your Part D plan (if you have one) will send you a notice in the mail. This notice lists what is changing for the next year: your monthly premium, your deductible, your copays for doctor visits and hospital stays, and which drugs are covered.

You should also check whether your doctors and pharmacies are still in your plan's network. Plans change their networks every year, and a doctor you have been seeing might no longer be covered. Call your doctor's office or your pharmacy and ask them to confirm they are in your plan for 2025 (or whatever year is coming).

If you take prescription drugs, look at the formulary — the list of covered medications. If your current plan no longer covers a drug you need, or if the copay went up, that is a strong reason to shop for a different plan during Open Enrollment.

When You Can Change Plans Outside of Open Enrollment

If you experience certain life events, you can change Medicare plans outside the regular October-December window. These are called may have access to Life Events, and they include moving to a new state or county, losing employer coverage, getting married or divorced, or the death of a spouse.

You typically have 60 days from the date of the event to make a change. For example, if you move to a new state on March 15, you have until May 14 to switch plans. You will need to provide proof of the event — a utility bill showing your new address, a letter from your employer, a marriage certificate, or a death certificate.

Other may have access to events include becoming a U.S. citizen, gaining or losing Medicaid coverage, or having a change in your income that affects your Medicare costs. If you think you have had a may have access to event, contact Medicare at 1-800-MEDICARE to ask whether you can change plans and what proof you need to provide.

Special Enrollment Periods and Who Qualifies

A Special Enrollment Period is the formal name for the window you get after a may have access to life event. The length of the period depends on the type of event. Most Special Enrollment Periods last 60 days from the date the event happened, but some are longer.

If you are in a Medicare Advantage plan and you move out of the plan's service area, you have a Special Enrollment Period to switch to a different plan. If you lose coverage through a former employer or spouse's employer, you have a Special Enrollment Period to join a Medicare plan. If you become newly may be able to access for Medicaid (the state program for low-income people), you also get a Special Enrollment Period.

The key difference between Open Enrollment and a Special Enrollment Period is timing: Open Enrollment happens the same time every year for everyone, while Special Enrollment Periods are triggered by your individual circumstances and happen whenever your event occurs.

What Happens If You Miss Open Enrollment

If you miss the December 7 important date and you do not have a may have access to life event, you cannot change plans until the next October. You will stay in your current plan for the entire year, even if the copays went up, your doctor left the network, or your drug is no longer covered.

There is one exception: if you have a may have access to life event after Open Enrollment ends, you can still change plans during your Special Enrollment Period. But if you straightforward forget to switch or decide too late that you want a different plan, you are locked in until October.

This is why it matters to mark your calendar in September. When you receive your plan change notices, set aside time to read them and compare your options. If you wait until December 5 to start looking, you might miss the important date.

How to Make Changes During Open Enrollment

You can change your Medicare plans in three ways: online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at a local Social Security office or State Health Insurance information Program (SHIP) office.

The easiest route for most people is Medicare.gov. Go to the "Find Care Providers" section, enter your zip code, and compare plans side by side. You can see the monthly premium, deductible, copays, and which drugs are covered for each plan. When you find a plan you want, you can switch right there on the website.

If you prefer to talk to someone, call 1-800-MEDICARE. A representative can walk you through your options and help you understand the differences between plans. If you need help in a language other than English, Medicare has interpreters available. You can also visit your local SHIP office — these are free counseling services run by each state, and the counselors can review your specific situation and help you decide.

Frequently Asked Questions

Can I change plans more than once during Open Enrollment?

Yes. You can switch plans as many times as you want between October 15 and December 7. However, only your last change will take effect on January 1. If you switch from Plan A to Plan B on November 1 and then from Plan B to Plan C on November 20, you will be in Plan C starting January 1.

What if I turn 65 during Open Enrollment?

If you turn 65 during Open Enrollment, you have a separate Initial Enrollment Period that lasts seven months — three months before the month you turn 65, the month you turn 65, and three months after. You can join any Medicare plan during this window, even if it is not the regular Open Enrollment Period.

Do I have to switch plans if my doctor left the network?

No, but you may want to. If your doctor is no longer in your plan's network, you have two choices: find a new doctor in the network, or switch to a plan that still includes your doctor. Some people stay with their current plan and change doctors; others switch plans to keep their doctor. The choice depends on how important continuity of care is to you.

What if I am on Medicaid and Medicare at the same time?

If you have both Medicare and Medicaid (called "dual may be able to access"), you can change plans during the regular Open Enrollment Period and also during a separate Medicaid Enrollment Period that runs January 1 through March 31. You may have more flexibility to switch than people with Medicare alone.

Can I go back to my old plan if I do not like the new one?

Not until the next Open Enrollment Period, unless you have a may have access to life event. If you switch plans on January 1 and realize by February that you made a mistake, you are stuck with the new plan until December 7 of that year. This is why it is important to compare carefully before you switch.