When Medicare Open Enrollment Happens and What You Need to Do

Medicare Open Enrollment Runs From October 15 to December 7 Each Year

Open Enrollment for Medicare is a fixed window every year: October 15 through December 7. During these eight weeks, you can join a Medicare Advantage plan, switch between plans, drop coverage, or move to Original Medicare. Changes you make during Open Enrollment take effect on January 1 of the following year.

Outside this window, you cannot change plans unless you have a may have access to life event — moving to a new state, losing employer coverage, getting married, or experiencing a similar change. If you miss Open Enrollment and have no may have access to event, you are locked into your current plan for the full year.

The exact dates shift slightly each year because they are tied to the calendar, not a fixed day of the week. Mark October 15 on your calendar now so you do not miss the start. Many people wait until November or December, which is fine, but waiting until the last week creates risk if you have questions or run into problems.

Key Takeaways

Open Enrollment happens every year from October 15 to December 7, and any changes you make take effect January 1.
You can only change Medicare plans during this window unless you have a may have access to life event like moving or losing coverage.
You do not have to change plans — if you do nothing, your current coverage continues into the next year.
Plan costs, coverage, and networks change every year, so reviewing your options during Open Enrollment can save you money.
You can enroll by phone, online at Medicare.gov, or through a local counselor — all three routes are free.

What Changes You Can Make During Open Enrollment

During the October 15 to December 7 window, you can switch from one Medicare Advantage plan to another, move from Medicare Advantage to Original Medicare, or move from Original Medicare to a Medicare Advantage plan. You can also drop prescription drug coverage (Part D) or add it if you do not currently have it. If you are in Original Medicare, you can change your Medigap supplemental plan during this period.

You cannot make changes to Original Medicare itself — Part A (hospital) and Part B (medical) are continuous once you turn 65 and enroll. But you can change the supplemental coverage that wraps around it. The same applies to prescription drug plans: you can switch from one Part D plan to another, or drop Part D entirely if you have other coverage.

If you are currently in a Medicare Advantage plan and do nothing during Open Enrollment, your plan automatically renews for the next year. This is important: inaction means you stay in your current plan. You do not need to re-enroll every year unless you want to change.

Why You Should Review Your Plan Every Year

Even if you are happy with your current plan, the details change every January. Premiums go up or down, deductibles shift, networks of doctors and hospitals change, and the list of covered drugs (the formulary) is updated. A plan that was the cheapest option last year might cost more this year, or your doctor might leave the network.

Spending an hour during Open Enrollment comparing your current plan to alternatives can reveal savings of hundreds of dollars per year. Medicare.gov has a plan comparison tool that shows you side-by-side costs and coverage for every plan available in your area. You enter your current medications, preferred doctors, and hospitals, and the tool shows you which plans cover them and what you will pay.

People often assume their plan is the best because they chose it years ago. But the market shifts constantly. A plan that made sense in 2022 might not be the best choice in 2025. Open Enrollment is the only time you can act on that information without a may have access to event.

How to Enroll or Change Plans During Open Enrollment

You have three main routes: online at Medicare.gov, by phone at 1-800-MEDICARE (1-800-633-4227), or through a local counselor. All three are free and available during Open Enrollment.

The online route is fastest if you know which plan you want. Go to Medicare.gov, log in with your username and password, and follow the prompts to compare plans or make changes. You can complete the entire process in 20 to 30 minutes. The site shows you your current plan, what it costs, and side-by-side comparisons with other options in your area.

The phone line (1-800-MEDICARE) is useful if you have questions or want someone to walk you through the comparison. Wait times are long during October and November, so calling in early December is often faster. Representatives can answer questions about specific plans, help you understand costs, and process your enrollment over the phone.

Local counselors are free advisors funded by Medicare. They meet with you in person or by phone and help you understand your options without pushing you toward any particular plan. To find a counselor near you, search "State Health Insurance information Program" (SHIP) plus your state name, or call 1-800-MEDICARE and ask for a referral.

What Happens If You Miss Open Enrollment

If October 15 to December 7 passes and you have not made a change, you are locked into your current plan for the full year. You cannot switch to a different plan, drop coverage, or move to Original Medicare unless you have a may have access to life event.

may have access to events include moving to a new state, losing employer coverage, getting married or divorced, having a baby, or experiencing a significant drop in income. If any of these happen, you have 60 days from the event to make a change. You will need to document the event — a lease showing your new address, a letter from your employer saying coverage ended, a marriage certificate, or a tax return showing income loss.

If you miss Open Enrollment and have no may have access to event, your only option is to wait until the next October 15. This is why marking the dates on your calendar matters: the cost of missing it is a full year of potentially higher premiums or worse coverage.

Special Enrollment Periods for Specific Situations

Beyond the main Open Enrollment window and may have access to life events, Medicare recognizes certain situations that trigger a Special Enrollment Period. These are narrower windows tied to specific circumstances.

If you are turning 65 and newly may be able to access for Medicare, you have a seven-month window centered on your birth month to enroll without penalty. If you are still working and covered by an employer plan, you can delay enrolling in Part B without a late penalty, but you must enroll within eight months of losing that coverage. If you are on Medicaid and lose it, you have 60 days to enroll in a Medicare plan.

These periods are shorter and have stricter rules than Open Enrollment. If you think you might may have access to for a Special Enrollment Period, call 1-800-MEDICARE to confirm the exact dates and what documentation you need.

Frequently Asked Questions

What happens to my current plan if I do nothing during Open Enrollment?

Your plan automatically continues into the next year with the same coverage and any new premiums or changes that take effect January 1. You do not need to do anything to keep your current plan. However, you should review it during Open Enrollment to make sure the costs and coverage still work for you.

Can I change plans more than once during Open Enrollment?

Yes. You can switch plans multiple times during the October 15 to December 7 window. Only your final choice counts — whatever plan you are enrolled in on December 7 is what you have starting January 1. There is no penalty for changing your mind.

Do I have to enroll in a prescription drug plan if I am in Original Medicare?

Prescription drug coverage (Part D) is optional, but there is a penalty if you go without it and later enroll. If you have no other drug coverage, it is usually cheaper to enroll in Part D during Open Enrollment than to pay the penalty later. If you have coverage through an employer or veteran benefits, you may not need Part D.

Can I change my Medigap plan during Open Enrollment?

Yes, you can switch Medigap plans during Open Enrollment. However, Medigap carriers can charge you more based on your health history if you switch outside of certain windows. Your best protection is to enroll in a Medigap plan when you first turn 65, when carriers cannot deny you or charge more for pre-existing conditions.

What if I need help understanding my plan options?

Call 1-800-MEDICARE to speak with a representative, or search for your State Health Insurance information Program (SHIP) to connect with a free local counselor. Both can explain your options and answer questions about costs and coverage without steering you toward any particular plan.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.