What Is the Medicare Annual Enrollment Period?
The Medicare Annual Enrollment Period (AEP) is a time when those already enrolled in Medicare or Medicare Advantage can make changes to their plan selection. This period runs from October 15 to December 7 every year, with changes going into effect January 1 of the following year.
Medicare is a federal health insurance program for people 65 and older and younger adults with certain disabilities. The program can help beneficiaries pay for a variety of medically necessary and preventive health services. You can only make changes to your coverage at specific times during the year. The AEP, sometimes known as Fall Open Enrollment, is one of those times.
Table of Contents
- What Is the Medicare Annual Enrollment Period?
- Original Medicare vs. Medicare Advantage: In a Nutshell
- How Does the Medicare Annual Enrollment Period Work?
- How to Prepare For the Medicare AEP
- How to Make Changes During the Medicare AEP
- Missed the AEP? Other Medicare Enrollment Periods to Note
- Putting It All Together
- Frequently Asked Questions
- Additional Resources
Original Medicare vs. Medicare Advantage: In a Nutshell
Medicare Parts A and B, also known as Original Medicare, is the traditional program managed by the federal government. It offers coverage for medically necessary services like doctor visits and hospital stays. This type of plan is also compatible with Medicare Supplement insurance (Medigap), which can help cover Medicare’s out-of-pocket expenses, such as copays and coinsurance.
Medicare Advantage Plans, on the other hand, are an alternative offered by private companies. These plans also cover Part A and B services, but may have additional coverages as well as different out-of-pocket costs and rules for accessing care.
As the Annual Enrollment Period allows for those with Medicare to switch plans — including from Original Medicare to Medicare Advantage, and vice versa — it is important to take advantage of this time to reevaluate your coverage to ensure it is still meeting your needs.
How Does the Medicare Annual Enrollment Period Work?

The Medicare Annual Enrollment Period (AEP) is a yearly window, during which time those who are already enrolled in Medicare or Medicare Advantage can change their existing coverage. Note that those without current Medicare coverage cannot use this period to enroll for the first time.
Making changes during the AEP is optional. Medicare members who are satisfied with their current coverage can continue their enrollment without changes so long as their plan is still being offered.
AEP Dates and Deadlines
The Medicare AEP runs from October 15 to December 7 every year. Beneficiaries may make changes as many times as they would like during this time, and all selections made by December 7 will go into effect January 1 of the following year.

My advice to individuals who are new to AEP is to take your time and shop around. Start on October 15 and take some days to look at different plans and make an informed decision after you have reviewed at least 3 options. When comparing different Medicare plans, such as Part C and D, look at the big picture of what you want your current coverage and future coverages to look like. You may not need dental or hearing coverage today, but maybe in 3-6 months you will.
What You Can Do During the AEP
During the Medicare Annual Enrollment Period, people with Medicare can make a variety of changes to their coverage. Overall, these are the changes beneficiaries can make during this period:
- Switch from Original Medicare to Medicare Advantage
- Switch from Medicare Advantage back to Original Medicare
- Switch from one Medicare Advantage plan to another
- Enroll in, drop, or switch a Medicare Part D prescription drug plan
There may be some limitations depending on your current enrollment situation. To better understand what you can do during the AEP window, consider your current enrollment status.
Currently Enrolled in Original Medicare
- You have Original Medicare only, or Part A and/or Part B only: You may join a Medicare Advantage Plan with or without bundled Part D coverage, join a Part D plan, or join both if your MA Plan does not offer bundled Part D coverage
- You have Original Medicare and Part D: You may join a Medicare Advantage Plan with or without bundled Part D coverage, switch to a different Part D plan, or drop Part D coverage entirely
Currently Enrolled in Medicare Advantage
- You have Medicare Advantage with bundled Part D coverage: You may switch a different Medicare Advantage Plan with or without bundled Part D coverage, switch back to Original Medicare, or join a stand-alone Part D plan if you also switch to an MA Plan without bundled Part D or switch back to Original Medicare
- You have Medicare Advantage without bundled Part D coverage: You may switch a different Medicare Advantage Plan without bundled Part D coverage, switch to a different Medicare Advantage Plan with bundled Part D coverage, or switch back to Original Medicare
Keep in mind that there may be future penalties for some changes made during the AEP, such as leaving a Medicare prescription drug plan. If you leave a Medicare drug plan and do not have comparable coverage from another plan, you may pay the Part D late enrollment penalty if you decide to join another Medicare drug plan in the future.
How to Prepare For the Medicare AEP
In the weeks leading up to the Medicare Annual Enrollment Period, take the time to review your current coverage and evaluate your care needs. Research other plan options and think about the changes you want to make.
1. Review your current coverage.
Even if you’re satisfied with your current plan, it’s important to review your coverage before the AEP. Medicare Advantage Plans and Medicare drug plans may change their coverages, costs, and provider networks from one year to the next.
Each fall, Medicare plans notify members of upcoming changes through an Annual Notice of Change (ANOC). The changes take effect on January 1st of the next year. Review the letter to see if any updates negatively affect you.
2. Evaluate your care needs.
Medicare beneficiaries’ health needs can change over time. They may receive a new diagnosis, take different medications, switch doctors, or have less room in their budget for monthly premiums.
Consider how well your plan is meeting your current needs and how it may or may not meet your needs in the new year. For example, if you want to see your dentist but do not have dental coverage, you may prefer a Medicare Advantage Plan with dental benefits.
3. Research Medicare plans and options.
There are several ways to find Medicare health and drug plans. Beneficiaries can use government sources such as the back of their Medicare and You handbook, or work with a trusted broker or agent to help guide them through the plans in their area.
Compare each plan’s benefits and costs to identify options that may suit your needs. Look at the Star Rating, too. Medicare rates plans from 1 to 5 based on several factors, including care quality, member satisfaction, and customer service.
4. Gather necessary documents to make a change.
To make changes during the AEP, be prepared to provide information from your Medicare card. Plans ask for your Medicare number and the date your coverage started. Sometimes, plans request proof a person lives in the service area. Documents that may meet this requirement include utility bills and driver’s license records.
How to Make Changes During the Medicare AEP
Beneficiaries have the opportunity to make a variety of coverage changes during the Medicare Annual Enrollment Period. Here’s an overview of how to change your coverage.
- Switch from Original Medicare to Medicare Advantage. Join your preferred plan during the AEP by contacting Medicare, the plan provider, or enrolling with the help of a licensed agent or broker. If you have a Part D plan and join a Medicare Advantage Plan that includes prescription drug coverage, the Part D plan ends automatically.
- Switch from Medicare Advantage back to Original Medicare. Unenroll from your Medicare Advantage Plan by submitting an unenrollment request. You can do this by calling your insurer or Medicare. Beneficiaries who switch back to Original Medicare can buy a Part D drug plan if desired.
- Switch from one Medicare Advantage Plan to another. Join a new plan during the AEP by calling Medicare, contacting the insurer directly, or working with a licensed agent or broker. There’s no need to cancel the old Medicare Advantage Plan. The old plan automatically ends when the new plan takes effect.
- Enroll in, drop, or change a Medicare Part D plan. Join a new plan by contacting Medicare or the plan provider. After switching, the old drug plan automatically ends when the new plan starts. If you no longer want Part D coverage, you can drop it by calling Medicare or submitting an unenrollment request.

When working with an agent, have all of your information available to review with them, including your doctor’s name and city and your current prescriptions, including quantity and refill rates. Share what you are comfortable sharing so the agent can find a plan to meet your specific health needs.
Missed the AEP? Other Medicare Enrollment Periods to Note
If you missed the AEP, you do not necessarily need to wait until next year to make Medicare coverage changes. Depending on your situation, you may have access to other Medicare enrollment periods.
Medicare Advantage Open Enrollment Period
The Medicare Advantage Open Enrollment Period (MA OEP) begins shortly after the AEP ends. It runs from January 1 to March 31 each year and is only available to people who are already enrolled in a Medicare Advantage Plan.
During the MA OEP, Medicare Advantage members have the option to make a single change to their coverage. They can either switch to another Medicare Advantage Plan (with or without drug coverage) or return to Original Medicare (with or without a Part D drug plan).
Special Enrollment Period
A Special Enrollment Period (SEP) allows Medicare beneficiaries to make changes to their coverage outside of the recurring enrollment windows. Beneficiaries are eligible for a SEP if they experience certain qualifying life events.
The timing of the SEP and the changes you can make vary depending on the type of life event. Generally, people who are eligible for a SEP have the option to join a plan or switch to a different plan.
Common Qualifying Life Events
Medicare provides SEPs for a long list of life events and special circumstances. Some of the more common events include:
- Moving to a new address: Moving outside your plan’s service area, returning to the U.S. after living abroad, or moving into or out of an institution trigger a SEP.
- Losing your current coverage: Leaving coverage from an employer or losing eligibility for Medicaid are examples of qualifying loss of coverage events.
- Getting government assistance: Those with Medicaid, Extra Help, and/or State Pharmaceutical Assistance Programs benefit from additional SEPs.
Putting It All Together
The Medicare Annual Enrollment Period is a yearly opportunity for anyone with Medicare to make changes to their coverage. From October 15 to December 7, beneficiaries are allowed to switch between Original Medicare and Medicare Advantage, switch Medicare Advantage Plans, or join, switch, or drop their Medicare drug plan.
Before the AEP starts, take the time to review your current plan and determine if it’s still meeting your needs. If not, start looking into new Medicare coverage options with the help of a trusted agent.
Frequently Asked Questions
Additional Resources
- The Centers for Medicare & Medicaid Services: This is the official website of the Centers for Medicare & Medicaid Services (CMS), which administers the Medicare program. It provides information on the annual enrollment period, including key dates, coverage options, and how to make changes to your coverage. You can find this information at: Joining a Health or Drug plan
- The Social Security Administration: This is the official website of the Social Security Administration, which provides information on the annual enrollment period for Medicare. It explains when the enrollment period takes place, what changes can be made, and how to enroll. You can find this information at: When to Sign Up For Medicare
- Medicare Interactive: This is a non-profit organization that provides information and assistance to people with Medicare. Its website provides information on the annual enrollment period, including what changes can be made, how to compare plans, and where to get help. You can find this information at: Six things to know about Fall Open Enrollment
- The National Council on Aging: This is a non-profit organization that provides information and resources on a range of issues affecting older adults, including Medicare. Its website provides information on the annual enrollment period, including what changes can be made, how to compare plans, and where to get help. You can find this information at: Medicare Enrollment Periods