Check your eligibility to start planning your coverage
Learn about Medicare open enrollment dates and who’s eligible to enroll in our plans.
Who is eligible for Medicare Advantage?
You are eligible to enroll in one of our plans if you:
Have Medicare Part A and Part B
Not enrolled in Part A and Part B?
Live in these Massachusetts counties
Bristol, Dukes, Essex, Middlesex, Nantucket, Norfolk, Plymouth, Suffolk, and Worcester.
When can you sign up for Medicare Advantage?
You can only sign up for Medicare Advantage after certain life events or during certain times of year. Learn more about the four types of enrollment periods:
You first become eligible for Medicare during your Initial Enrollment Period (IEP).
IEP is a 7-month period that typically starts 3 months before the month of your 65th birthday and ends 3 months after you turn 65.
You can also enroll in Medicare Advantage during specific times of year.
Annual Enrollment Period (AEP)
Oct 15 - Dec 7
If you already have Medicare, during AEP you can enroll in Medicare Advantage, switch plans, or leave a plan.
Jan 1 → Coverage starts
If you enroll by December 7, your plan coverage goes into effect on Jan 1.
Open Enrollment Period (OEP)
Jan 1 - Mar 31
If you’re already enrolled in Medicare Advantage, you can switch to a different Advantage plan during OEP or drop your plan and return to original Medicare.
Some people qualify for Medicare Advantage coverage outside of standard enrollment periods. Special Enrollment Periods (SEP) take place when certain qualifying events happen, including losing employer coverage, retiring, or moving. Learn more about all of the Medicare Special Enrollment Periods.
Some people under 65 may also qualify for Medicare based on disability. IEP for someone who qualifies based on disability begins 3 months before their 25th month of disability benefits and ends 3 months after. Learn more about Medicare eligibility based on disability.
Enroll in your plan
Ready to enroll? If you’ve verified your eligibility and are within a qualifying enrollment period, you can sign up for one of our Medicare Advantage plans now.
Frequently Asked Questions
Most people become eligible for Medicare Advantage after turning 65 and enrolling in Original Medicare (Part A and B).
Medicare is also available for some people with disabilities under 65. To qualify for this coverage, individuals need to meet specific criteria with the Social Security Administration which can be verified on their website.
You can only enroll in Medicare during specific enrollment periods, or under special circumstances. Individuals with disabilities may be able to enroll before they turn 65 and outside of standard enrollment periods. You may also be able to enroll based on certain qualifying events, including losing employer coverage or retiring.
Medicare Advantage has several enrollment periods throughout the year with different requirements for eligibility.
Initial Enrollment Period (IEP) typically begins 3 months before the month of your 65th birthday and ends 3 months after.
Annual Enrollment Period (AEP) runs from October 15 to December 7. You can enroll in a new Medicare Advantage plan, switch plans, or leave a plan.
Open Enrollment Period (OEP) runs from January 1 to March 31. You can switch plans during this time or return to Original Medicare but can’t enroll in a new plan.
The IEP is slightly different for people born on the first of the month. If you were born on the 1st, your IEP begins 4 months before the month of your 65th birthday and ends 2 months after.
Example: Your birthday is June 1st. When you turn 65, your Initial Enrollment Period is February-August.
Some people under 65 may also qualify for Medicare based on disability. IEP for someone who qualifies based on disability begins 3 months before their 25th month of disability benefits and ends 3 months after. Learn more about Medicare eligibility based on disability on the Social Security Administration website.
© 2025 Mass General Brigham Health Plan, Inc.
Mass General Brigham Health Plan is an HMO-POS/PPO organization with a Medicare contract. Enrollment in Mass General Brigham Health Plan depends on contract renewal. Other providers/pharmacies are included in our network.
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Mass General Brigham One Care is a Dual Special Needs Plan (D-SNP) that contracts with both Medicare and MassHealth (Medicaid) to provide benefits of both programs to enrollees. Enrollment in the plan depends on the plan’s contract renewal with Medicare. This plan is a voluntary program that is available to anyone age 21 - 64 who qualifies for MassHealth Standard or CommonHealth and Original Medicare and does not have any other comprehensive health insurance, except Medicare.
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Mass General Brigham SCO (Senior Care Options) is a Dual Special Needs Plan (D-SNP) with a Medicare contract and a contract with the Commonwealth of Massachusetts Medicaid program. Enrollment in the plan depends on the plan’s contract renewal with Medicare. This plan is a voluntary program that is available to anyone 65 and older who qualifies for MassHealth Standard and Original Medicare and does not have any other comprehensive health insurance, except Medicare.
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Last updated: 10/1/2025
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