Does all Medicare private coverage have open enrollment periods?

  • By
  • medicareresources.org Contributor
  • September 14, 2018

Q: Does all Medicare private coverage have annual open enrollment periods?

How well are you prepared to enroll in Medicare? Take the Medicare Smarts quiz.

How well are you prepared to enroll in Medicare? Click the graphic to take our brief quiz.

A: No, it doesn’t – and it’s important to know the difference before you enroll:

For Medicare Advantage and Medicare Part D, there’s an annual open enrollment period (October 15 to December 7, with enrollments effective January 1 of the coming year). During this time, you can switch to any other Medicare Advantage or Part D plan available in your area, regardless of your medical history. (One caveat: if you’re on a Medicare Advantage plan and you’re diagnosed with end-stage renal disease, you’ll be limited to Medicare Advantage plans offered by your current carrier, unless your carrier stops offering plans in your area.)

And starting in 2019, there’s an annual Medicare Advantage open enrollment period during which people who are enrolled in Medicare Advantage plans can switch to different Medicare Advantage plans (or to Original Medicare).

But there’s no annual open enrollment period for Medigap (Medicare Supplement) plans. You can apply for a Medigap plan anytime, but after your initial six-month enrollment window has passed, the carrier can use your medical history to determine your eligibility and premium. However, states can impose their own regulations for Medigap plans, such as:

  • In MassachusettsNew York and Connecticut, Medigap plans are not medically underwritten, regardless of when an applicant enrolls.
  • In California, there’s a 30-day window each year, following a Medigap enrollee’s birthday, when he or she can switch to any other available Medigap plan with equal or lesser benefits, without medical underwriting.
  • In Missouri, there’s a 30-day window each year, preceding a Medigap enrollee’s policy anniversary date, when he or she can switch to the same letter Medigap plan from a different insurer, guaranteed-issue and without any waiting period for pre-existing conditions.
  • In Maine, Medigap insurers are required to make at least one plan (Plan A) available on a guaranteed-issue basis to any applicant for at least one month each year.
  • If you have questions, check with your state SHIP or your state’s Division of Insurance for more information.

If you’re in good health, you’ll be able to switch to a different Medigap plan, but some Medigap plans are priced based on the enrollee’s age when the plan is issued, so they’ll be more expensive if you enroll later, even if you’re healthy (a handful of states require Medigap plans to be community rated, but most do not).

There are some limited special enrollment periods during which residents in any state have access to all or some Medigap plans with no medical underwriting. (See page 10-11.) These include circumstances where your old Medigap plan is no longer available (if you moved out of the plan area, or the carrier stopped offering the plan, for example), the carrier didn’t follow the rules, or you’re in your one-year “trial period” after selecting or switching to Medicare Advantage and you want to go back to Original Medicare and a Medigap plan (note that if you initially had Original Medicare + Medigap and you switched to Medicare Advantage and now want to switch back during your trial period, your guaranteed-issue right for Medigap will be limited to the same Medigap plan you had before, unless it’s no longer available).

So while Medicare Advantage and Part D plans have annual open enrollment periods during which all plans are guaranteed-issue, the same is not true for Medigap plans. This is part of the reason many Medigap enrollees choose comprehensive plans despite higher premiums.

Plan F is the most comprehensive option. In 2016, 55 percent of Medigap enrollees were enrolled in Plan F, including the high-deductible version of Plan F. The next most popular choice -Plan G – garnering just 10 percent of enrollees, and Plan C, which had 11 percent of enrollees in 2013, had dropped to 7 percent of enrollees in 2016.

Plan F and Plan C will no longer be available to new enrollees after 2019, as the Medicare Access and CHIP Reauthorization Act of 2015 (MACRA) disallows the sale of plans that cover the Part B deductible starting in 2020. Plan G is the next most comprehensive Medigap plan, providing coverage for all of Medicare’s out-of-pocket costs except the Part B deductible. America’s Health Insurance Plans reported that enrollment in Plan G grew from 6 percent to 10 percent from 2013 to 2016.


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.