Annual Enrollment Period, AEP
**When:  October 15th to December 7th each year.
**What: The time to make changes to your Medicare plans, such as switching between Medicare Advantage plans or adding/dropping a Part D prescription drug plan.  This is your opportunity to review your current coverage and make adjustments to ensure it aligns with you changing needs and budget.

Open Enrollment Period, OEP
**When: January 1st to March 31st each year.
**What:  A limited time to switch Medicare Advantage plans, but you can't return to the Original Medicare or change your Part D.  This is a good time to compare plans and find one that offers better benefits or lower costs.

Initial Enrollment Period, IEP
**When: Three months before you turn 65, your birthday month, and three months after.
**What: The time to first enroll in Medicare Parts A & B, a Medicare Advantage plan, or a Part D plan.  This is  crucial because you may face late enrollment penalties if you don't enroll during your IEP.

Key Points:
**Timing is critical.  Avoid late enrollment penalties by enrolling during your IEP.
**Consult with a professional.  A Medicare specialist can help you understand your options and choose the best plan for your circumstances.
**Review your coverage regularly.  Your health needs and Medicare plan may change over time.  It's important to review your coverage annually to ensure it continues to meet your needs.

Additional Considerations:
**Medicare Advantage Plans:  These plans combine Part A, B, and sometimes Part D into a single plan.  They often offer additional benefits like prescription drug coverage, vision, dental and hearing aids.  
**Part D Prescription Drug Plans:  If you don't have a Medicare Advantage plan, you'll need a Part D plan to cover your prescription drug costs.
**Medigap plans:  These plans can help fill in the gaps of original Medicare.  They can cover deductibles, copayments, and coinsurance.