Unlike other types of Medicare coverage, beneficiaries can apply for Medigap any time they like. But in most states, there is no annual open enrollment period for Medigap.
Instead, there’s a one-time six-month Medigap open enrollment period. It begins when a person is at least 65 years old and enrolled in Medicare Part B, and Medigap plans are guaranteed-issue during this window. Many states offer at least some variation of this for Medicare beneficiaries who are under 65. After that window ends, many enrollees will not have another guaranteed-issue opportunity to enroll in Medigap.
But some states have annual guaranteed-issue opportunities to enroll in Medigap or at least switch to a different plan:
- In New York and Connecticut, Medigap plans are not medically underwritten, regardless of when an applicant enrolls. Legislation was introduced in 2024 that would create a similar rule in New Jersey, but the bills had not advanced as of mid-2025.
- In Massachusetts, there’s an annual guaranteed-issue Medigap open enrollment period each year, from February 1 through March 31, with coverage effective in June. Insurers also have the option of offering continuous year-round open enrollment, and all of them were doing so as of 2024. Legislation was introduced in South Carolina in 2024 to would create a one-month window each year during which all Medigap plans would be guaranteed-issue, but the bill did not pass.
- In Maine, Medigap insurers must designate one month each year when Plan A is guaranteed issue, regardless of the applicant’s medical history. Legislation was considered in Iowa in 2024 to create a similar annual enrollment period; it had passed the Iowa House in 2023, but subsequently died in the Senate.
- Missouri‘s “anniversary rule” allows enrollees to switch from one Medigap insurer to another (as long as both plans are the same letter) on a guaranteed-issue basis during a window each year that extends for 30 days before and 30 days after the anniversary of when the plan was first purchased.
- California, Idaho, Illinois, Oregon, Nevada, Louisiana, Maryland, Oklahoma, Kentucky, Utah, Virginia, Wyoming, Delaware (starting in 2026), and Indiana (starting in 2026) have “birthday rules” that allow Medigap enrollees a time-limited window around their birthday each year when they can switch, without medical underwriting, to another Medigap plan. This is generally limited to a plan with the same or lesser benefits (in Illinois and Louisiana, this is also limited to a plan offered by the enrollee’s current Medigap insurer; in Kentucky, it’s limited to the enrollee’s same policy offered by another insurer).
- Washington and Oklahoma allow those already enrolled in Medigap plans to switch to another Medigap plan at any time, as long as they’ve had coverage for at least 90 days (Oklahoma regulators have clarified that an issuer complies as long as they offer, at least, a birthday rule plan change opportunity). In Washington, enrollees with Medigap Plan A are limited to switching to only another Plan A. But people with Medigap Plans B through N can switch to any other Plan B through N. In Oklahoma, enrollees are allowed to switch to any plan with equal or lesser benefits.
- Minnesota enacted legislation in 2023 that calls for a guaranteed issue window for Medigap, aligning with the current federal annual enrollment periods for Medicare Advantage and Medicare Part D. It was initially slated to take effect in August 2025, but that has been delayed to August 2026. Additional legislation was enacted in 2025, calling for higher premiums for people utilizing the new guaranteed-issue enrollment window to sign up for Medigap for the first time. And the issue remains controversial. Some stakeholders, including the insurer that holds the majority of the Medigap market share in Minnesota, have asked lawmakers to repeal the new guaranteed-issue open enrollment period before it takes effect.
- Rhode Island enacted legislation in 2025 to create a guaranteed-issue window for Medigap plans, aligning with the timing of the Medicare annual election period (Oct. 15 to Dec. 7). For anyone who has had Medicare Advantage or Medigap coverage since their initial Medicare enrollment period (with no gap in coverage of more than 90 days), the fall election period will include guaranteed-issue access to Medigap plans, without medical underwriting.
States considering legislation to ensure access to Medigap when a person switches from Medicare Advantage to Original Medicare
Washington state lawmakers introduced a bill in 2025 that would allow for guaranteed-issue access to Medigap when a person disenrolls from Medicare Advantage during an open enrollment period or special enrollment period, and enrolls in Original Medicare instead. But the legislation was still in committee as of October 2025.
A second bill introduced in Washington in 2025 would create a guaranteed-issue Medigap provision during any open enrollment period for Medicare Part B (meaning the annual General Enrollment Period) or Medicare Advantage (meaning the fall open enrollment period). But the legislation was still in committee as of October 2025.
Lawmakers in Illinois introduced legislation in 2025 that would ensure guaranteed-issue access to Medigap during a 30-day window after a person switches from Medicare Advantage to Original Medicare. (As noted above, Illinois already has a birthday rule.)
New Hampshire lawmakers have also introduced legislation in 2025 that would require Medigap coverage to be guaranteed issue during the Medicare Open Enrollment Period, allowing people guaranteed access to Medigap after disenrolling from Medicare Advantage or a different Medigap plan. The bill would also require all insurers that offer Medicare Advantage in New Hampshire to also offer Medigap coverage. It was still in committee as of October 2025.
Federal rules allow for guaranteed-issue access to Medicare Part D when a person switches from Medicare Advantage to Original Medicare, but not Medigap (unless the person qualifies for one of the limited federal Medigap special enrollment rights).
States considering legislation to ensure annual guaranteed issue access to Medigap
Lawmakers in Iowa are considering legislation in 2025 that would require Medigap insurers to offer applicants at least one policy on a guaranteed-issue basis during the month of March, starting in 2026. However, the legislation defines “applicant” as a person already enrolled in a Medigap plan, so this would be a plan change opportunity rather than a new enrollment opportunity. The bills were still in committee as of October 2025.
Lawmakers in Vermont are considering legislation that would create an annual open enrollment period for Medigap, aligning with the existing Oct. 15 to Dec. 7 open enrollment period for Medicare Part D and Medicare Advantage. The legislation was still in committee as of October 2025.
California lawmakers introduced legislation in 2025 to create an annual open enrollment period for Medigap, starting January 1 and continuing for 90 days. The bill was still in committee as of October 2025. Similar legislation was introduced in 2024 in California, but was not successful.
As noted above, California already has a “birthday rule” that allows people who already have Medigap to switch to a different plan that offers equal or lesser benefits. But the 90-day annual enrollment period would apply to all applicants (including those who are not yet enrolled in Medigap) and all plans.