Medicare Open Enrollment: Exactly What You Can Change (and What You Can’t)

From October 15 to December 7, Medicare’s Annual Enrollment Period (AEP) gives you a once-a-year chance to adjust your coverage. To use it well, you need to know precisely what’s on the table — and what isn’t.

Change 1: Switch Between Original Medicare and Medicare Advantage

During Open Enrollment, you can:

• Move from Original Medicare (Part A and Part B) to a Medicare Advantage (Part C) plan.
  This often means getting your hospital, medical, and sometimes drug coverage in one plan, usually through a private insurer.

• Drop Medicare Advantage and return to Original Medicare.
  You can go back to using your red-white-and-blue card for Part A and Part B services.

Important: When you return to Original Medicare, you may not automatically qualify for a Medigap (Medicare Supplement) policy with guaranteed acceptance. Medigap enrollment rules are separate and can depend on your state and health status.

Change 2: Change Medicare Advantage Plans

If you already have Medicare Advantage, you can:

• Switch from one Medicare Advantage plan to another, with or without drug coverage.
• Change the type of plan, for example from an HMO to a PPO, if options are available in your area.

This is the main time each year to respond to changes in premiums, provider networks, or benefits in your current plan.

Change 3: Add, Drop, or Change Part D Drug Coverage

If you get your prescription coverage through a standalone Part D plan or a Medicare Advantage plan with drug coverage (MAPD), you can:

• Enroll in a Part D plan if you don’t have one and are eligible.
• Switch from one Part D plan to another to get a better formulary, lower costs, or preferred pharmacies.
• Drop Part D coverage entirely, if you decide you don’t need it.

Be aware: Going without creditable drug coverage for a period of time can lead to a late enrollment penalty if you sign up again later.

Change 4: Align Your Coverage With Your Current Needs

Open Enrollment is also the time to:

• Review plan changes in your Annual Notice of Change (ANOC) and Evidence of Coverage (EOC).
• Check whether your doctors, hospitals, and pharmacies will still be in-network next year.
• Confirm your medications are on the plan’s formulary and at a cost level you can manage.

You cannot use this period to enroll in Part A or Part B for the first time (that happens during your Initial Enrollment Period or the General Enrollment Period), and it does not give you special rights to buy any Medigap plan you want.

Putting It All Together

Think of Medicare Open Enrollment as your annual opportunity to:

• Reevaluate: Does your current plan still fit your health, medications, and budget?
• Compare: Look at other Medicare Advantage and Part D options in your area.
• Act: Make changes between October 15 and December 7 so they start January 1.

Knowing exactly what you can change — and the limits on what you can’t — puts you in control of your Medicare coverage for the year ahead.