Most people approaching retirement look forward to enjoying Medicare benefits. To maximize these valuable benefits, they should also understand the importance of signing up for the right Medicare options and enrolling at the right time. This Medicare Enrollment Period guide can help ensure timely enrollment to avoid penalties or even worse, a lapse in coverage.

Medicare Enrollment Period Chart

Initial Enrollment Period (IEP): Beneficiaries can enroll in Original Medicare, Medicare Part D, and a Medicare Advantage plan for seven months, including the 65th birthday month, the previous three months, and the following three months. The period will start in the previous month for people with a birthday on the first day of the month.
Medicare Advantage -Initial Coverage Election Period (ICEP): This period runs concurrently with the IEP and represents the seven-month period Medicare enrollees can join a Medicare Advantage plan. For individuals who are just qualifying into Medicare they can enroll in an Medicare Advantage plan during ICEP.
Initial Enrollment Period 2 (IEP2): The government provides this enrollment period for people who could enroll in Medicare before turning 65 because of a qualifying illness or disability. It works the same as the IEP.
Special Enrollment Periods (SEP): Some people have special circumstances that allow them to enroll in Medicare Part D or Medicare Advantage outside of the regular enrollment periods. The SEP generally lasts for 60 days after the qualifying event. People who don’t enroll in Part B because they have job-based health insurance also get an SEP after losing this coverage, which lasts eight months.
Medicare Part B Special Enrollment: Medicare-eligible people who delayed Part B enrollment because of creditable coverage from a job may have up to eight months after that coverage ends to enroll in Part B.
General Enrollment Period (GEP): Eligible people who missed their IEP can enroll in Medicare Part A and Part B from January 1 to March 31. These people can also enroll in Part D from April 1 to June 30.
Medicare Supplement (aka Medigap) Open Enrollment: This is a one-time only enrollment period, typically occurring when a person ages into Medicare at 65 providing new beneficiaries with the Guaranteed Issue Rights to Medigap plans. For individuals receiving Medicare Part B before their 65th birthday their Medigap OEP starts the first day of the month they turn 65 as well. If there is an enrollment delay going past turning 65 then the Medigap OEP will automatically start the month of enrolling in Medicare Part B.
Fall Open Enrollment Period (AEP): This can also be referred to an open enrollment period (OEP). It is purposed for dropping, changing or joining: Medicare Advantage and/or a Part D plan. This time period is between October 15th to December 7th. This period enables enrollees to make a greater number of changes vs the Medicare Advantage Open Enrollment Period (MAOEP). Changes take effect January 1st.
Medicare Advantage – Open Enrollment Period (MAOEP): This limited Open Enrollment Period runs between January 1st to March 31st. Enrollees in MA plans can switch or drop Medicare Advantage to return to Original Medicare and enroll in a stand-alone Part D drug plan. This difference from AEP in the sense that you cannot make the following changes during this period: switch from Original Medicare to an MA plan, join a Medicare Part D (prescription plan) if on Original Medicare, or switch from one Part D plan to another if on Original Medicare.

More to Consider About Medicare Enrollment Periods

The IEP:

Most beneficiaries will enroll in Medicare Part A, B, and D, during these seven months. Waiting until after the IEP Enrollment Period ends can result in delays, a lack of health insurance and prescription coverage, and penalties for late enrollment. People who will have job-based group health insurance might be able to delay Medicare Part B without a penalty.


The ICEP gives Medicare recipients a chance to enroll in Medicare Advantage instead of relying only on Original Medicare. Many Medicare Advantage plans include Part D prescription benefits. A beneficiary does not need to, and cannot, enroll in both a Medicare Part D plan and a Medicare Advantage plan with drug coverage.

Medigap Open Enrollment:

During this Open Enrollment period, insurers can’t ask any health questions, so they cannot charge more or decline applications for pre-existing conditions. People who choose Medigap will also need a Part D plan.

During times other than the Open Enrollment period, a Medigap insurance company could deny coverage or charge more for applicants with certain health conditions. Beneficiaries can get guaranteed issue rights because of special circumstances, but even then, these rights may be limited to only some Medicare supplement plans.

The AOP:

Every fall, beneficiaries with Part D or Medicare Advantage plans get a chance to review changes or additions to their chosen plans. People can then choose new plans or sign up for Medicare Advantage for the first time.

Outside of the ICEP or IEP and Annual Open Enrollment, beneficiaries can only join a new plan because of certain circumstances. These circumstances might include having a plan canceled or leaving the plan’s service area.

The SEP:

Some beneficiaries qualify for an SEP for factors beyond their control. Some examples might include leaving a Medicare Advantage plan service area or losing a job-related health insurance plan. Most of the time, beneficiaries have 60 days after the event to enroll in new coverage.

Prudent Medicare beneficiaries will act as soon as they foresee losses in coverage to ensure they time their entry into new Medicare plans correctly. A licensed Medicare insurance agent can answer any specific questions the beneficiary might have.


  1. When Does Medicare Coverage Start?, Medicare.