As a retiree, it's critical that you have the right healthcare coverage. That's why anyone who's currently enrolled in a Medicare Advantage plan needs to take action by March 31, as that's an important date for participants in the program.

Here's why March 31 is so important and what to do if you're enrolled in a Medicare Advantage plan.

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A major deadline for Medicare Advantage participants

March 31 is the end of the Medicare Advantage Open Enrollment period that starts on Jan. 1. This January-to-March 31 period is different from open enrollment in the fall, as only current Medicare Advantage enrollees are allowed to participate in it.

During this period, those who are enrolled are allowed to make one change. They can either:

• Switch to a different Medicare Advantage plan
• Switch to original Medicare, either with or without Part D coverage

Medicare Advantage Plan enrollees have the option to make these changes regardless of whether they currently have prescription drug coverage -- with one exception. If you're currently covered by a Medicare Part D plan, you're allowed to change either to an Advantage plan without prescription drug coverage or to original Medicare. You aren't allowed to make changes to your Medicare Part D coverage during your open enrollment period.

This exception affects very few people, though, since close to 90% of Advantage Plans in 2025 offered prescription coverage as a plan benefit.

What should Medicare Advantage plan participants do before March 31?

If you're enrolled in a Medicare Advantage Plan, there are a few things that you should do before March 31:

• Review your insurance usage over the past year, as well as your expected future medical needs in the coming year.
• Determine if your current Medicare Advantage plan is still meeting your needs.
• Explore alternative Medicare Advantage Plans, comparing things like premiums and coverages to see if a different plan is a better fit.

If you want to explore your options or if you decide that you want to make changes, you can do so by using the Medicare Plan Finder or by calling 1-800-MEDICARE (1-800-633-4227).

Taking the time to confirm your coverage can help you avoid extra out-of-pocket spending out of your retirement plans, which is critical to your long-term financial security. Most people will not have another chance to make changes to their Medicare plans until October unless they qualify for a special enrollment period, so take advantage of this opportunity now.

Healthcare is typically one of the biggest things that retirees spend their money on. Having the right Medicare Advantage or traditional Medicare plan in place can make a big impact on your total spending in this expensive area.