A: Medicare open enrollment occurs each fall, from October 15 to December 7. During that time, you can switch from Original Medicare to Medicare Advantage, or vice versa. If you are already enrolled in a Medicare Advantage plan, you can drop it and enroll in Original Medicare and a Part D plan during open enrollment, with coverage effective January 1.
And between January 1 and March 31 each year, if you are enrolled in a Medicare Advantage plan, you can decide to leave your plan and return to Original Medicare (and purchase a Part D plan to supplement your Original Medicare coverage), OR you can switch to a different Medicare Advantage plan. (This option became available as of 2019; prior to that, there wasn’t an option to switch from one Medicare Advantage plan to another in the first part of the year).
There are also some circumstances in which you’ll have a special enrollment right that will allow you to switch from Medicare Advantage to Original Medicare or enroll for the first time.
But in most states, you will not have guaranteed issue access to a Medicare supplemental insurance (Medigap) plan when you leave Medicare Advantage to switch to Original Medicare, although there are some exceptions to this.
You can enroll in a Medigap plan, but you will generally be subject to medical underwriting unless you qualify for a Medigap special enrollment period or guaranteed issue right — which does include some limited situations in which the enrollee is switching from Medicare Advantage to Original Medicare during the trial right period.
But some states have regulations to ensure ongoing access to Medigap plans, outside of the initial Medigap open enrollment period:
- New York and Connecticut don’t allow medical underwriting for Medigap plans.
- Maine requires Medigap insurers to offer at least Medigap Plan A on a guaranteed-issue basis for at least one month each year.
- Massachusetts has an annual window, from February 1 through March 31, when Medigap plans are guaranteed-issue.
- Missouri requires Medigap insurers to allow enrollees to switch to the same letter plan from another insurer on a guaranteed-issue basis during a 30-day period each year preceding the anniversary of when the plan was originally purchased (this is known as the state’s “anniversary rule”).
- California and Oregon have “birthday rules” that give Medigap enrollees a 30-day window each year (following the enrollee’s birthday), when he or she can switch to any other available Medigap plan that has equal or lesser benefits, without medical underwriting.
- Washington state allows Medigap enrollees to switch to another Medigap plan at any time, as long as they’ve had Medigap coverage for at least 90 days. People with Medigap Plan A can only pick another Plan A. But people with Medigap Plans B through N can switch to any other Plan B through N.
You can click on your state on this map to see details about how Medigap is regulated in your state. You can also check with your State Health Insurance Assistance Program (SHIP) if you have Medicare-related questions.
Choosing between Medicare Advantage and Original Medicare
Medicare Advantage plans often have lower total premiums than Original Medicare plus Part D and Medigap coverage. But you need to assess all your costs to ensure that you get the coverage that best meets your needs. That includes including premiums, of course, but also out-of-pocket medical costs, prescription costs, and potential costs you might incur if you venture outside of an Advantage plan’s provider network.
Out-of-pocket costs will typically be higher under Medicare Advantage than they would be with Original Medicare plus Part D and Medigap coverage, and the provider network will be narrower and generally more localized with a Medicare Advantage plan.
Here’s a guide to help you decide whether you’d be better off with Medicare Advantage or with Original Medicare plus supplemental coverage.
Louise Norris is an individual health insurance broker who has been writing about health insurance and health reform since 2006. She has written dozens of opinions and educational pieces about the Affordable Care Act for healthinsurance.org. Her state health exchange updates are regularly cited by media who cover health reform and by other health insurance experts.