Important Medicare Dates
Important Medicare Dates & Enrollment Periods
Understanding Medicare isn’t just about choosing the right coverage. Timing matters.
Medicare has specific enrollment periods throughout the year, and missing an important deadline could delay your coverage, limit your options, or result in a late enrollment penalty.
At Health Coverage Solutions, we help you understand not only your Medicare options, but also when you need to take action.
Important Medicare Dates for 2026–2027
September 2026 — Review Your Annual Notice of Change
If you currently have a Medicare Advantage or Medicare Part D prescription drug plan, your plan will send you an Annual Notice of Change (ANOC) each fall.
Your ANOC explains changes to your plan for the upcoming year, which may include:
- Monthly premiums
- Deductibles
- Copayments and coinsurance
- Prescription drug coverage
- Provider networks
- Pharmacy networks
- Additional benefits
- Other coverage changes
Plans send the ANOC in September, and Medicare guidance provides for members to receive it by September 30.
Don’t assume that because your plan worked well this year, it will be the best choice next year.
October 1, 2026 — Start Comparing 2027 Medicare Plans
Beginning October 1, Medicare beneficiaries can start reviewing and comparing Medicare Advantage and prescription drug plan options for the upcoming year.
This gives you time to review your current coverage and compare it with the plans available for 2027 before Medicare Open Enrollment begins.
You should consider changes to:
- Your prescription medications
- Your preferred pharmacies
- Your doctors and specialists
- Your health care needs
- Your plan's premiums and out-of-pocket costs
- Your current plan's benefits for the upcoming year
October 15, 2026 — Medicare Annual Enrollment Period Begins
The Medicare Annual Enrollment Period, commonly called AEP or Medicare Open Enrollment, begins each year on October 15.
During AEP, Medicare beneficiaries can make certain changes to their Medicare Advantage and prescription drug coverage.
You may be able to:
- Change from one Medicare Advantage plan to another
- Change Medicare Part D prescription drug plans
- Move from Original Medicare to Medicare Advantage
- Leave Medicare Advantage and return to Original Medicare
- Add or change prescription drug coverage when permitted
Changes made during this period generally become effective January 1 of the following year.
December 7, 2026 — Medicare Annual Enrollment Period Ends
December 7 is generally the final day of Medicare’s Annual Enrollment Period.
For most people, any Medicare Advantage or Part D enrollment change for the following year must be submitted by this date.
If you make a change during AEP, your new coverage generally begins January 1.
January 1, 2027 — New Medicare Plan Coverage Begins
Changes made during the Medicare Annual Enrollment Period generally take effect on January 1.
If you changed Medicare Advantage or Part D plans, your new coverage begins.
If you stayed with your existing plan, any changes to your plan’s premiums, benefits, cost-sharing, formulary, or other coverage generally take effect on January 1 as well.
January 1 – March 31 — Medicare Advantage Open Enrollment Period
The Medicare Advantage Open Enrollment Period, or MA OEP, runs from January 1 through March 31 each year.
This enrollment period is specifically for people who are already enrolled in a Medicare Advantage plan.
During this period, you may generally make one change to:
- Switch from one Medicare Advantage plan to another Medicare Advantage plan, with or without prescription drug coverage; or
- Leave Medicare Advantage and return to Original Medicare, with the opportunity to enroll in a separate Part D prescription drug plan.
What You Cannot Do During the Medicare Advantage Open Enrollment Period
If you have Original Medicare, this period does not allow you to:
- Enroll in Medicare Advantage
- Enroll in a Part D plan simply because it is the MA Open Enrollment Period
- Switch from one stand-alone Part D plan to another
Changes generally become effective the first day of the month after the plan receives your enrollment request.
January 1 – March 31 — Medicare General Enrollment Period
The General Enrollment Period (GEP) also runs from January 1 through March 31 each year.
This enrollment period is primarily for people who did not enroll in Medicare Part A and/or Part B when they were first eligible and who do not qualify for another enrollment opportunity.
Coverage generally begins the month after you enroll.
Depending on your circumstances, a late enrollment penalty may apply.
Medicare Enrollment Dates Based on Your Birthday
Not every important Medicare date falls on the same date for everyone.
Some of the most important Medicare enrollment periods are based specifically on when you become eligible for Medicare.
Your Medicare Initial Enrollment Period
For most people becoming eligible for Medicare at age 65, your Initial Enrollment Period (IEP) lasts seven months.
It generally includes:
- 3 months before your 65th birthday month
- Your 65th birthday month
- 3 months after your 65th birthday month
Example
If you turn 65 in June, your Initial Enrollment Period generally runs:
March 1 through September 30
This is typically your first opportunity to enroll in Medicare Part A and Medicare Part B.
When your coverage begins can depend on when during your Initial Enrollment Period you enroll.
Important: Special timing rules apply if your birthday falls on the first day of the month.
Medicare Supplement Open Enrollment Period
Your Medicare Supplement Open Enrollment Period is different from Medicare’s Annual Enrollment Period.
Under federal law, your Medicare Supplement Open Enrollment Period lasts six months and begins the first month that you are:
Age 65 or older AND enrolled in Medicare Part B.
During this six-month period, you can generally purchase any Medicare Supplement policy available to you without the insurance company using medical underwriting to deny your application based on your health.
This is an important one-time enrollment opportunity.
Your Medicare Supplement Open Enrollment Period does not happen every year.
Important: AEP Is NOT Medicare Supplement Open Enrollment
This is one of the most commonly misunderstood Medicare rules.
The October 15 through December 7 Annual Enrollment Period is primarily for Medicare Advantage and Medicare Part D coverage.
It is not an annual Medicare Supplement or Medigap Open Enrollment Period.
You do not need to wait until October 15 to apply for a Medicare Supplement.
However, outside your Medicare Supplement Open Enrollment Period or another guaranteed issue situation, medical underwriting may be required depending on your circumstances and state law.
That means your ability to change Medicare Supplement plans can be very different from your ability to change Medicare Advantage or Part D plans.
Working Past 65? Your Medicare Dates May Be Different
If you are still working when you turn 65 and have qualifying employer group health coverage through your or your spouse’s current employment, you may be able to delay Medicare Part B without a late enrollment penalty.
When the employment or qualifying employer coverage ends, you generally receive an 8-month Special Enrollment Period to enroll in Medicare Part B.
The eight-month period begins when employment ends or the qualifying group health coverage ends, whichever happens first.
COBRA does not extend this Medicare Part B Special Enrollment Period.
If you want Medicare to begin immediately after your employer coverage ends, it is important to start planning before retirement rather than waiting until your employer coverage has already terminated.
Medicare Special Enrollment Periods
Certain life events may provide a Special Enrollment Period (SEP) that allows you to enroll in or change Medicare coverage outside of the normal enrollment periods.
Examples can include:
- Retiring and losing qualifying employer coverage
- Moving outside your Medicare Advantage or Part D plan's service area
- Your Medicare plan terminating or leaving your area
- Losing certain other health coverage
- Moving into or out of certain institutions
- Becoming eligible for Medicaid or Extra Help
- Losing Medicaid eligibility
- Certain emergencies, disasters, or exceptional circumstances
Each Special Enrollment Period has its own rules and deadlines.
Don’t assume you need to wait until October 15 if something has changed with your coverage. You may have another enrollment right available.
If Your Medicare Advantage Plan Is Terminating
If your Medicare Advantage plan will no longer be available in your area for the following year, you may have additional enrollment rights.
You should receive a notice explaining that your plan is not renewing or will no longer be available to you.
These situations can create important options for:
- Returning to Original Medicare
- Selecting another Medicare Advantage plan
- Enrolling in Medicare Part D
- Potentially purchasing certain Medicare Supplement plans using guaranteed issue rights
Before choosing another plan, make sure you understand all of your options and any deadlines that apply.
Medicare Dates at a Glance
| Date or Time Period | What Happens |
|---|---|
| January 1 | New Medicare plan coverage and annual benefit changes begin |
| January 1 – March 31 | Medicare Advantage Open Enrollment Period |
| January 1 – March 31 | Medicare General Enrollment Period for certain people enrolling in Part A and/or Part B |
| September | Watch for your Annual Notice of Change |
| By September 30 | Review your plan's upcoming changes |
| October 1 | Begin comparing Medicare Advantage and Part D options for the following year |
| October 15 | Medicare Annual Enrollment Period begins |
| December 7 | Medicare Annual Enrollment Period ends |
| Around Your 65th Birthday | 7-month Medicare Initial Enrollment Period |
| Once 65+ and Enrolled in Part B | 6-month Medicare Supplement Open Enrollment Period |
| After Qualifying Employer Coverage Ends | A Medicare Part B Special Enrollment Period may apply |
Don't Wait Until the Deadline to Review Your Medicare Coverage
While Medicare provides specific enrollment deadlines, we recommend reviewing your options before the last few days of an enrollment period.
This gives you time to:
- Review your doctors
- Review your prescriptions
- Compare plan costs
- Understand network restrictions
- Review your current plan's changes
- Ask questions
- Understand whether Medicare Advantage or Original Medicare with Medicare Supplement coverage is appropriate for you
At Health Coverage Solutions, we believe Medicare decisions should be based on education—not pressure.
Our team can help you understand your Medicare options, important enrollment dates, and what actions, if any, you need to take.
Independent Guidance and Education.
Have a Medicare Question?
Schedule a Medicare Consultation with Health Coverage Solutions.Understanding Medicare terminology is helpful, but knowing how all of the pieces work together is even more important.
Have a Medicare question? Schedule a Medicare consultation with Health Coverage Solutions.