Calendar
See explanations below calendar
| Period | Dates | Who | What You Can Do |
|---|---|---|---|
| Initial Enrollment | 7 months around 65th birthday | Turning 65 | First-time enrollment |
| General Enrollment | Jan 1 – Mar 31 | Missed IEP | Sign up (penalties possible) |
| Annual Enrollment | Oct 15 – Dec 7 | All beneficiaries | Change plans |
| MA Open Enrollment | Jan 1 – Mar 31 | Advantage members | Switch/drop Advantage |
| Special Enrollment | Varies | Qualifying events | Adjust coverage |
| Medigap Open Enrollment | 6 months after Part B starts | New Part B enrollees | May be able to change to supplement |
Initial Enrollment Period (IEP)
Your Initial Enrollment Period (IEP) is a 7‑month window that is tied to your 65th birthday:
3 months before your birthday month
Your birthday month
3 months after your birthday month
Example:
If your 65th birthday is in June, your IEP runs from March 1 through September 30.
Note – this may change. There has been debate about shortening the window.
General Enrollment Period (GEP)
January 1 to March 31
Available if you missed your initial window, with coverage beginning the month after enrollment.
Annual Enrollment Period (AEP)
Medicare Annual Enrollment Period (AEP) is the time each year when people with Medicare can review and make changes to their coverage.
📅 October 15 to December 7 every year
What you can do during this period
Switch from Original Medicare (Part A & B) to a Medicare Advantage (Part C) plan, or vice versa
Change from one Medicare Advantage plan to another
Join, drop, or switch a Part D (prescription drug) plan
Adjust your coverage based on changes in your health, medications, or costs
When changes take effect
Any changes you make during AEP become active on January 1 of the following year
Why it matters
Plans can change every year (costs, covered drugs, networks), so AEP is your chance to:
Lower costs
Get better coverage
Ensure your doctors and medications are still included
Medicare Advantage Open Enrollment Period
January 1 to March 31.
Allows you to switch Medicare Advantage plans or return to Original Medicare.
Does not allow you to switch to a Supplement plan.
Special Enrollment Period (SEP)
A Special Enrollment Period (SEP) is a time outside the standard enrollment windows when you’re allowed to sign up for, switch, or drop Medicare plans due to certain life events.
Normally, Medicare has fixed enrollment periods (like the Annual Enrollment Period), but SEPs give flexibility if your situation changes.
Common reasons you may qualify for a Medicare SEP
1. Loss of other health coverage
You lose employer coverage (retirement or job loss)
Your COBRA coverage ends
👉 Typically gives you an 8‑month window to enroll in Medicare Part B
2. Moving to a new area
You move to a different state or ZIP code
👉 Lets you switch Medicare Advantage or Part D plans that better fit your new location
3. Gaining or losing Medicaid eligibility
You qualify for Medicaid (dual eligibility)
Or you lose Medicaid
👉 Allows plan changes, sometimes multiple times per year
4. Qualifying for Extra Help (Low-Income Subsidy)
If you get Extra Help for prescription drug costs
👉 You can change plans more frequently
5. Entering or leaving a care facility
Skilled nursing facility
Long-term care facility
👉 You can change plans while you’re there and for a limited time after leaving
6. Plan-related issues
Your Medicare plan:
Ends its contract
Changes coverage significantly
What Can You Do During a SEP?
Depending on your situation, you can:
Enroll in Original Medicare (Part A & B)
Join, switch, or drop a Medicare Advantage plan
Join, switch, or drop a Part D prescription drug plan
Important Notes
SEPs are time-limited—they often last 2–8 months, depending on the situation.
The exact rules depend on why you qualified for the SEP.
If you miss your SEP window, you may have to wait for the next general enrollment period—and could face penalties.