You can enroll anytime during an enrollment period - and you may wish to enroll as early as possible just to have the decision behind you - or if your health status is currently changing, you may wish enroll later in the enrollment period so that your Medicare plan choice can include coverage of your latest prescription and healthcare (and healthcare provider) needs.

We recommend: Not too early and not too late.
Your Medicare Part D or Medicare Advantage plan will need about 10 business days to process your new enrollment application - so we usually recommend that you enroll at least 2-weeks before the end of the enrollment period allowing a buffer for any administrative or technical errors that may require you to correct your application - or re-enroll into the same Medicare plan before the enrollment period expires.  And, since none of us know the future, sometimes our health needs change unexpectedly and enrolling too early may mean that our chosen Medicare Part D or Medicare Advantage plan no longer provides the best coverage if our healthcare needs change before the end of the enrollment period.

• Enrollment timing during the Medicare Annual Open Enrollment Period (AEP)

Waiting until the end of AEP.
If you wait to complete your enrollment or plan change until early-December, your Medicare plan may not have enough time to confirm your enrollment and send you a "Welcome" letter or initial plan information before the December 7th closing of the AEP - and every year we hear from people who learn of application processing errors after the close of the AEP - and they are then forced to correct any errors to ensure that they have any plan coverage on January 1st -  or people get busy and forget that December 7th is the end of AEP.

• Enrollment timing during your Initial Enrollment Period (IEP)

Your Medicare Part D Initial Enrollment Period (IEP) is a 7-month period that begins 3 months before the month when you become eligible for Medicare (when you turn 65) - plus the month that you are eligible for Medicare - and continues for 3 months after your Medicare eligibility month.  No matter when you enroll during the IEP, Medicare plan coverage will not begin before the Medicare eligibility month and if you enroll on or after your Medicare eligibility month, your plan coverage will begin the first day of the month after enrollment.

Too early?
Like the AEP above, if you enroll too early during your IEP, you may find that you have changes in your health or prescription needs before the start of your Medicare eligibility month.  So if you wish to have coverage starting the 1st day of your Medicare eligibility month, you probably should enroll midway through the month before Medicare eligibility so your Medicare plan will have plenty of time to send you the plan material before coverage begins - or you can correct any enrollment errors and still have coverage starting the 1st of the month.  (For example, if you turn 65 in June, choose your Medicare plan coverage during early- or mid-May to ensure that your current healthcare and prescription needs are met by the Medicare plan.)

Saving the premiums and starting Medicare plan coverage as late as possible?
If you are in good and stable health and do not need Medicare Part D or Medicare Advantage plan coverage (and want to save a few months premium), you could wait until mid-way through the last of the seven-month Initial Enrollment Period - again, if there is an enrollment problem, you should have enough time to correct the problem or re-enroll before your IEP closes.  (For example, if you turn 65 in June, you have up to 3 months to enroll into a Medicare Part D or Medicare Advantage plan after June, so if you do not need health or prescription coverage and want to save on premiums, you can wait until mid-September to enroll with plan coverage beginning October 1st.)  But, if you wait too long, you may find that you have missed your IEP and will need to wait until an AEP to add Medicare plan coverage - and may incur the permanent late-enrollment penalty unless you have some other form of creditable prescription drug coverage.

• Enrollment timing during a Special Enrollment Period (SEP)

You may have the opportunity to change your Medicare Part D or Medicare Advantage plan coverage outside the AEP if circumstances arise allowing for a Special Enrollment Period (SEP) - for example, you move outside your Medicare plan's Service Area or enter a Long-term Care Facility or you lose your employer's healthcare coverage.  The length of a Special Enrollment Period can vary with the situation, with most SEPs being a relatively short amount of time (63 days).  Like other enrollment periods, we recommend that you use your SEP well before the ending date to be able to correct any enrollment errors and have time to understand your coverage before your newly-chosen Medicare plan begins.

• Changing Medicare Advantage plans during the Medicare Advantage plan Open Enrollment Period (MA-OEP)