What You Can Do During AEP
Understand permitted changes, effective dates, and what does not require action.
Join or change Advantage
During October 15–December 7 Open Enrollment, an eligible person can join an available Medicare Advantage plan, switch from one Advantage plan to another, or return to Original Medicare. The plan generally must get the election by December 7 for a January 1 effective date. Use the exact residence ZIP and check both A/B enrollment, network and plan ID.
Official source: Medicare: Open Enrollment ↗ · Medicare: Joining a plan ↗
Change prescription arrangements
The same window allows eligible changes to standalone Part D or to an Advantage plan with appropriate drug coverage. If leaving an Advantage plan for Original Medicare, assess whether you need a separate Part D plan. A late-enrollment penalty can apply after a sufficiently long gap without Part D or creditable drug coverage. Confirm how the intended plan handles your actual medications.
Official source: Medicare: Open Enrollment ↗ · Medicare: Creditable drug coverage ↗ · Medicare: Joining a plan ↗
Understand the Medigap distinction
Changing to Original Medicare does not automatically guarantee acceptance into any Medigap plan. Federal and state guaranteed-issue rules have defined events and deadlines, and the six-month Medigap open enrollment period does not recur every fall. Before dropping an Advantage or existing Medigap plan, verify the exact future Medigap right with the insurer or state insurance department.
Official source: Medicare: Buying Medigap ↗ · Medicare: Original versus Advantage ↗
Keeping the current plan is allowed
After reviewing the Annual Notice of Change, you may decide that your current plan still fits. In most cases, no new election is needed for that plan to continue into January, but new costs and benefits take effect. Confirm that your providers, pharmacy and prescribed drugs remain suitable for the new plan year.
Official source: Medicare: Yearly review ↗ · Medicare: Annual Notice of Change ↗
Check the new coverage afterward
Save proof of your election and confirm the new effective date and ID cards. Review the next-year Evidence of Coverage and file a plan inquiry or coverage determination for a disputed service. If you joined Advantage and later discover an issue, the separate January–March Advantage Open Enrollment window may allow one change, subject to its rules.
Official source: Medicare: Joining a plan ↗ · Medicare: Evidence of Coverage ↗ · Medicare: Advantage enrollment windows ↗