How to Switch Medicare Plans: A Complete Guide

When Can You Switch Medicare Plans?

Medicare plan changes are generally only allowed during specific enrollment periods. Understanding when you can switch is the first step:

Annual Enrollment Period (AEP): October 15 - December 7 each year. This is the primary window for making any changes to your Medicare coverage. Changes take effect January 1.

Medicare Advantage Open Enrollment Period (MA OEP): January 1 - March 31 each year. Only for people already enrolled in a Medicare Advantage plan. You can switch MA plans or return to Original Medicare. One change allowed.

Special Enrollment Periods (SEPs): Available when qualifying life events occur, such as moving, losing coverage, or qualifying for Medicaid. Timing and duration vary by event.

5-Star Special Enrollment Period: Available year-round if you are switching to a plan with an overall CMS 5-star rating.

Open Enrollment Period for Part B: January 1 - March 31 for people who missed their Initial Enrollment Period (coverage starts July 1, penalties may apply).

Switching Between Medicare Advantage Plans

If you currently have a Medicare Advantage plan and want to switch to a different MA plan, you have two annual opportunities:

During the AEP (October 15 - December 7): You can switch to any Medicare Advantage plan available in your area. This is the broadest switching window.

During the MA OEP (January 1 - March 31): You can make one change to switch to a different MA plan. If you already used the AEP to pick a new plan and it is not working out, the MA OEP gives you one more opportunity to switch.

When switching MA plans, verify that your doctors and hospitals are in the new plan's network, check that your prescriptions are covered on the new plan's formulary, compare copays, deductibles, and out-of-pocket maximums, and review extra benefits like dental, vision, and hearing.

Switching from Medicare Advantage to Original Medicare

You can leave your Medicare Advantage plan and return to Original Medicare during the AEP (October 15 - December 7) or during the MA OEP (January 1 - March 31).

When switching back to Original Medicare, you will likely want to add a stand-alone Part D prescription drug plan for medication coverage and consider purchasing a Medigap (Medicare Supplement) policy to cover Original Medicare's cost-sharing.

The Medigap consideration is important: outside of your initial Medigap Open Enrollment Period (the 6-month window when you first turned 65 and enrolled in Part B), insurance companies can use medical underwriting to decide whether to sell you a Medigap policy. You may be denied coverage or charged higher premiums based on your health status.

Some states provide guaranteed issue rights for Medigap when you leave a Medicare Advantage plan. Check your state's specific rules. Connecticut, Maine, Massachusetts, Missouri, New York, and Oregon are among states with broader Medigap protections.

Switching from Original Medicare to Medicare Advantage

If you have Original Medicare and want to join a Medicare Advantage plan, you can do so during the Annual Enrollment Period (October 15 - December 7). Changes take effect January 1.

If you join a Medicare Advantage plan that includes prescription drug coverage (MA-PD), your stand-alone Part D plan (if you have one) will automatically be terminated. Similarly, you cannot use a Medigap policy with a Medicare Advantage plan — you should contact your Medigap insurer about suspending or dropping your policy.

Some things to consider before switching: verify your preferred doctors are in the MA plan's network, check your prescriptions on the MA plan's formulary, understand the plan's referral and prior authorization requirements, review the annual out-of-pocket maximum, and consider whether you may want to return to Original Medicare in the future (Medigap underwriting could be an issue).

Switching Part D Prescription Drug Plans

You can switch Part D plans during the Annual Enrollment Period (October 15 - December 7) each year. Changes take effect January 1.

Reasons to switch Part D plans include your current plan dropping coverage of one or more of your medications, a drug moving to a higher cost tier, premium increases, your preferred pharmacy leaving the plan's network, finding a plan with lower total drug costs for your specific medications, or your plan's overall quality rating declining.

To compare Part D plans, use the Medicare Plan Finder at Medicare.gov with your complete medication list. The tool calculates estimated annual costs for each plan based on your specific drugs.

Remember that if you switch to a Medicare Advantage plan with drug coverage, your stand-alone Part D plan will be terminated automatically.