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Basic Medicare Information

When to Enroll in Medicare

When you’re 65 and new to Medicare, there can be a lot of dates to remember. But signing up for Medicare is simple. Get the key facts about enrollment here. 

Doctor consults senior woman patient.

What You Should Know About Enrollment Periods

Part A enrollment

If you’re receiving Social Security benefits, you’ll automatically be enrolled in Medicare Part A when you turn 65. If you’re delaying Social Security benefits past your 65th birthday, you’ll have to contact Social Security to enroll in Medicare Part A.

Part B enrollment

The best time to enroll in Medicare Part B is your Initial Enrollment Period—the seven-month period that starts three months before the month you turn 65, includes the month you turn 65 and ends three months after the month you turn 65. If you enroll in Medicare Part B after your Initial Enrollment Period, you may pay a monthly late enrollment penalty if you don’t qualify for a Special Enrollment Period.

Medicare Advantage (Part C) and Medicare Prescription Drug (Part D) Enrollment periods

There are four enrollment periods for Medicare Advantage plans and Medicare prescription drug plans. Review them below to find which one is right for you.

Initial Enrollment Period

When you first become eligible for Medicare, you can join during the seven-month period that starts three months before the month you turn 65, includes the month you turn 65 and ends three months after the month you turn 65.

Annual Enrollment Period

Anyone can join, switch, or drop a Medicare Advantage or Medicare prescription drug plan between October 15 and December 7. If you apply during this time, coverage begins on January 1.

Medicare Advantage Open Enrollment Period

The Medicare Advantage Open Enrollment Period is January 1 through March 31 each year. During this time Medicare Advantage enrollees can:

  • Have a Special Election Period to add or change Part D coverage
  • Enroll in another Medicare Advantage plan
  • Disenroll from a Medicare Advantage plan and return to Original Medicare

You may only make one election during the Medicare Advantage Open Enrollment Period. You are also eligible to participate in Open Enrollment if you are a new Medicare beneficiary who enrolled in a Medicare Advantage plan during your Initial Enrollment Period.

A Medicare Advantage eligible individual who elects Original Medicare during the Medicare Advantage Open Enrollment Period may elect to enroll in a prescription drug plan during this time. If so, the effective date of this coverage is the first of the first of the month following receipt of the enrollment request.

Special Enrollment Period

In most cases, you must stay in the plan for the calendar year when your coverage began. But you may be able to join, switch or drop a Medicare Advantage or Medicare prescription drug plan during a Special Enrollment Period. Below is a list of some, but not all the reasons you may need to change during a Special Enrollment Period:

  • Moving outside of the plan’s approved service area
  • Entering or leaving a qualified institution, such as a nursing home
  • Qualifying for low-income subsidy assistance (Extra Help)
  • Enrolling in Medicaid
  • Involuntarily losing creditable prescription drug coverage
  • Leaving or losing your employer’s health plan

Medicare Supplement Insurance Enrollment Periods

  • You can enroll in a Medicare Supplement Insurance Plan within six months of your Medicare Part B effective date.
  • This six-month Open Enrollment Period is the best time to enroll because it’s the only time when enrollment is guaranteed.
  • If you enroll in Medicare Supplement Insurance Plan after the Open Enrollment Period, you may have to meet certain requirements and could pay more for the plan.

Speak with a Medicare Plan Specialist

Contact us if any of these situations apply to you.

Call 1-877-260-0298 (TTY 711).

8:00 a.m. – 8:00 p.m. daily, local time. Calls April 1 – September 30 may go to voicemail on weekends and holidays.

For more information, refer to the Medicare and You Handbook .

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