Medicare Enrollment Dates & Penalties
Know when to enroll — and how to avoid costly surprises.
Medicare has specific enrollment windows that determine when you can sign up, make changes to your plan, or switch coverage. Missing a key date could result in delayed coverage or even lifelong penalties.
Medicare has specific enrollment windows that determine when you can sign up, make changes to your plan, or switch coverage. Missing a key date could result in delayed coverage or even lifelong penalties.
Annual Enrollment Period (AEP)
October 15 – December 7
Changes take effect January 1
If you already have Medicare, this is your once-a-year opportunity to:
- Switch from Original Medicare to a Medicare Advantage Plan (Part C)
- Switch from a Medicare Advantage Plan back to Original Medicare
- Change from one Medicare Advantage Plan to another
- Add, drop, or switch Part D prescription drug coverage
- Move between Medicare Advantage plans with or without drug coverage
Tip: Review your plan every year. Even small changes in premiums, copays, or covered medications can make a big difference.
Medicare Advantage Open Enrollment Period
January 1 – March 31
If you’re enrolled in a Medicare Advantage Plan (like an HMO or PPO), this is your chance to:
- Switch to a different Medicare Advantage Plan
- Drop your Advantage Plan and go back to Original Medicare
- Join a stand-alone Prescription Drug Plan (Part D) if you return to Original Medicare
Changes take effect the first day of the month after your plan receives the request.
This period does not apply if you only have Original Medicare (Parts A & B).
Special Enrollment Periods (SEPs)
Life happens — and Medicare gives you some flexibility.
A Special Enrollment Period allows you to make changes outside the regular windows if you’ve had a major life event, such as:
- Losing qualifying health coverage (job-based insurance)
- Moving to a new city, county, or state
- Joining a Medicare Advantage Plan when you were first eligible, and deciding (within 12 months) to switch back to Original Medicare
- Losing Medicaid or other extra help benefits
Important:
COBRA and retiree health plans do not count as creditable coverage. When they end, you’re not eligible for a SEP. To avoid penalties, enroll in Medicare when you are first eligible.
🔎 For the full list of SEPs, visit Medicare.gov
General Enrollment Period
January 1 – March 31
Coverage begins July 1
If you missed your Initial Enrollment Period, this is your annual chance to enroll in Medicare Part A and/or Part B.
But be aware: late enrollment penalties may apply — and you’ll wait until July 1 for your coverage to begin.
Understanding Medicare Late Enrollment Penalties
Delaying Medicare enrollment can result in permanent penalties, including:
Part B Penalty
If you don’t sign up for Part B when you’re first eligible and don’t have other creditable coverage, you’ll pay a 10% penalty for every 12-month period you delayed enrollment.
This penalty is added to your monthly premium for life.
Part D Penalty
If you delay enrolling in a Part D drug plan and go 63+ days without other creditable drug coverage, you’ll pay a penalty based on how long you went without coverage.
This penalty is also added to your premium for life.
Don’t Miss a Deadline — Let’s Plan Ahead Together
Understanding Medicare timelines can feel overwhelming — but that’s why we’re here. At Tailored Medicare, we help you:
Understand your enrollment options
Avoid unnecessary penalties
Choose a plan that fits your needs
Stay on top of future deadlines
today for free guidance and a step-by-step enrollment plan.