--- title: What you should know about the Medicare Annual Enrollment Period (AEP) description: Medicare open enrollment, also known as the Annual Enrollment Period, is when eligible individuals can review health insurance options and make changes. image: https://blog.massgeneralbrighamhealthplan.org/hubfs/iStock-2217502065.jpg --- [![MGB_Health_Plan_horiz_rgb-1](https://blog.massgeneralbrighamhealthplan.org/hubfs/Mass%20General%20Brigham%20Health%20Plan/Logos/MGB_Health_Plan_horiz_rgb-1.svg)](https://www.massgeneralbrighamhealthplan.org/) ![](https://blog.massgeneralbrighamhealthplan.org/hubfs/iStock-2217502065.jpg) # What you should know about the Medicare Annual Enrollment Period (AEP) Published by [Michael Buttimer](https://blog.massgeneralbrighamhealthplan.org/author/michael-buttimer) on September 14, 2026 Medicare open enrollment, also known as the Annual Enrollment Period (AEP), is when eligible individuals can review their health insurance options and make changes for the next plan year. It’s a chance to compare coverage, costs, provider networks, prescription drug benefits, and extra plan features before choosing the option that best fits their needs. ### **When is AEP?** AEP runs from October 15 to December 7. During AEP, Medicare members can change their plan and join, switch, or drop certain Medicare Advantage and prescription drug plans. Changes made during AEP begins January 1. ### **Additional Medicare enrollment periods** Medicare has multiple enrollment periods, which can make the timing confusing. - For people enrolling in Medicare for the first time, the **Initial Enrollment Period (IEP)** is a seven-month window that begins three months before their 65th birthday, includes their birth month, and ends three months after. - For people already enrolled in a Medicare Advantage plan, the **Medicare Advantage Open Enrollment Period** **(MA OEP)** runs from January 1 through March 31. Individuals may be able to switch to another Medicare Advantage plan or return to Original Medicare and add a Part D prescription drug plan. - A **Special Enrollment Period (SEP)** is a temporary window triggered by certain life events, such as moving, losing employer-sponsored coverage, or qualifying for Extra Help. An SEP lets members change plans outside standard enrollment dates. ### **Why AEP matters** Health needs can change each year. Providers may join or leave a network, prescription drug coverage may shift, and premiums, copays, deductibles, or out-of-pocket maximums may change for the next plan year. AEP gives people time to review their options and confirm their coverage still supports their care, budget, and preferences. ### **Preparing for AEP** Before AEP begins, gather what you need to compare plans. Review your current coverage, list the doctors and specialists you want to keep seeing, check your prescriptions, and consider the benefits you used most over the past year. If you expect changes in your health, finances, or care needs, include those in your decision. Before you start preparing for AEP, you should review your current plan’s coverage, costs, and benefits for the coming year. [Check out our complete **AEP checklist**](https://blog.massgeneralbrighamhealthplan.org/medicare-advantage-plan-shopping-checklist) to get started. ### **Next steps and resources** AEP helps ensure your health insurance still fits your life. Comparing plans can take time, especially if you need to confirm provider participation, review medication coverage, or ask eligibility questions. Starting early can help you make a more confident decision. If you have questions, Massachusetts residents can receive free Medicare-related health insurance information, counseling, and support through the [SHINE Program](https://www.mass.gov/info-details/serving-the-health-insurance-needs-of-everyone-shine-program), and Mass General Brigham Health Plan offers a [Medicare Basics guide](https://massgeneralbrighamadvantage.org/plans/new-to-medicare). To learn more about Medicare Advantage plans from Mass General Brigham Health Plan, please visit [MGBAdvantage.org](http://www.mgbadvantage.org). Mass General Brigham Health Plan is an HMO-POS organization with a Medicare contract. Enrollment in Mass General Brigham Health Plan depends on contract renewal. Our Medicare Advantage plans are available in Bristol, Dukes, Essex, Middlesex, Nantucket, Norfolk, Plymouth, Suffolk, and Worcester counties in Massachusetts. [Back to Blog](https://blog.massgeneralbrighamhealthplan.org) ## Related articles ## [Medicare Advantage plan shopping checklist](https://blog.massgeneralbrighamhealthplan.org/medicare-advantage-plan-shopping-checklist) Annual Enrollment Period (AEP) is a chance to make sure your health insurance still fits your... [Read More](https://blog.massgeneralbrighamhealthplan.org/medicare-advantage-plan-shopping-checklist) ## [Common health insurance terms and what they mean](https://blog.massgeneralbrighamhealthplan.org/common-health-insurance-terms-and-what-they-mean) Health insurance can be complex, with numerous terms and acronyms. So, wouldn’t it be helpful to... [Read More](https://blog.massgeneralbrighamhealthplan.org/common-health-insurance-terms-and-what-they-mean) ## [You may be eligible for a One Care or SCO (Senior Care Options) plan](https://blog.massgeneralbrighamhealthplan.org/you-may-be-eligible-for-a-one-care-or-senior-care-options-plan) Did you know that if you have both Medicare and MassHealth, you may be dual-eligible? This means... [Read More](https://blog.massgeneralbrighamhealthplan.org/you-may-be-eligible-for-a-one-care-or-senior-care-options-plan) Back to Top © 2026 Mass General Brigham Incorporated. All Rights Reserved.