The Annual Enrollment Period (AEP) is the time each year when Medicare beneficiaries can make changes to their health and prescription drug coverage for the upcoming calendar year. Designated by the federal government, the AEP provides an annual opportunity to assess how a current plan meets individual needs. This period is important because the structure, costs, and benefits of Medicare Advantage and Part D plans frequently change annually.
Defining the Annual Enrollment Period
The Medicare Annual Enrollment Period runs from October 15th to December 7th every year. This seven-week window is the primary time for current Medicare participants to select new coverage options. This fixed timeframe allows beneficiaries to review plan changes, compare options, and formally enroll in a new plan. Any changes finalized during the AEP will take effect on January 1st of the following year.
Before the enrollment period begins, insurance companies must send an Annual Notice of Change (ANOC) to all existing plan members. This document details any changes in premiums, deductibles, co-pays, or covered services for the following year. Reviewing the ANOC helps determine if the current coverage remains the best fit. If a beneficiary is satisfied with their existing plan and its changes, they do not need to take action, and their current coverage will automatically renew.
Coverage Changes Available During AEP
The AEP offers Medicare beneficiaries a wide range of options for modifying their coverage. A common action is switching between Original Medicare (Parts A and B) and a Medicare Advantage Plan (Part C). An individual in Original Medicare can enroll in a Medicare Advantage Plan, which bundles hospital, medical, and often prescription drug coverage into a single plan offered by a private insurer.
Conversely, a beneficiary enrolled in a Medicare Advantage Plan can disenroll and return to Original Medicare. This change may be accompanied by enrolling in a stand-alone Medicare Part D prescription drug plan and potentially a Medicare Supplement Insurance (Medigap) policy. Beneficiaries can also switch between different Medicare Advantage Plans, such as moving from an HMO to a PPO or vice versa.
Significant changes can also be made regarding prescription drug coverage. Since a plan’s formulary—the list of covered drugs—and its associated costs can change annually, reviewing Part D options is important for those with ongoing prescription needs. During the AEP, a beneficiary can enroll in a Part D plan for the first time, switch between plans, or drop coverage entirely. All changes made during the AEP are voluntary and not dependent on a specific life event.
Enrollment Options Outside of AEP
While the Annual Enrollment Period is the standard time for annual coverage changes, other enrollment periods exist for those who miss the deadline or experience a qualifying life event. The Initial Enrollment Period (IEP) is the first opportunity for an individual to enroll in Medicare. It typically begins three months before their 65th birthday month and ends three months after, creating a seven-month window.
Many individuals may qualify for a Special Enrollment Period (SEP), allowing them to make changes to their Medicare Advantage or Part D coverage outside of the AEP dates. An SEP is triggered by specific circumstances. These include moving to a new service area, losing employer-sponsored health coverage, or qualifying for Extra Help with prescription drug costs. These periods are granted for a limited time following the qualifying event, often 60 days.
The Medicare Advantage Open Enrollment Period (MA OEP) runs from January 1st through March 31st each year. This period is only for people already enrolled in a Medicare Advantage plan. It allows a one-time opportunity to switch to a different Medicare Advantage plan or switch back to Original Medicare. If returning to Original Medicare, the beneficiary can also enroll in a stand-alone Part D plan during the MA OEP.