State-Specific Medigap Rules & Birthday Rules

Most people know there's one key window to enroll in Medigap (Medicasre Supplement) without facing health questions or higher premiums: the six-month Medigap Open Enrollment Period that begins when you turn 65 and are enrolled in Medicare Part B. But what many people don't realize is that your state may give you additional opportunities to switch or enroll, sometimes every single year.

States with Continuous or Year-Round Protections

Three states offer some of the strongest Medigap protections in the country:

• New York and Connecticut require insurers to offer Medigap policies year-round on a guaranteed issue basis, meaning you can enroll or switch at any time without medical underwriting. 

• Massachusetts has its own standardized Medigap plan structure and provides continuous open enrollment. 

• If you live in one of these states, your options are significantly more flexible than in most of the country.

The Birthday Rule: What It Is and Where It Applies

As of 2026, more than a dozen states have adopted some version of a Medigap birthday rule. 

• This rule gives existing Medigap policyholders a guaranteed-issue window each year, typically around their birthday, during which they can switch to another Medigap plan without going through medical underwriting. 

• That means you can potentially get a better rate or change plan letters without being penalized for your health history.

The specifics vary significantly by state:

• California, Oregon, Idaho, Nevada, Oklahoma, Illinois, and Maryland have had birthday rules in place for several years. 

  • California's rule, for example, gives beneficiaries a 59-day window each year beginning on your birthday to switch to any Medigap plan with equal or lesser benefits, with any insurer, without underwriting.

• Kentucky, Utah, Virginia, Indiana, Delaware, and Wyoming added a birthday rule between 2024 and 2026. 

• West Virginia's birthday rule takes effect June 11, 2026. 

• New Mexico's rule is set to take effect January 1, 2027.

• Louisiana has a birthday rule that allows plan changes within 63 days of your birthday, though it is generally limited to the same insurer or affiliated carriers. 

• Maryland gives beneficiaries 30 days from their birthday to switch to a plan with equal or lesser benefits.

• Missouri has an anniversary rule rather than a birthday rule. The window is tied to when you first enrolled in your Medigap plan, not your birthday, and gives you 63 days to switch to an equal or lesser plan with any carrier. 

• Washington state allows certain plan changes year-round within the same insurer.

If Your State Doesn't Have a Birthday Rule

If you live in a state without a birthday rule or continuous enrollment protections, switching Medigap plans outside of your initial open enrollment period typically requires medical underwriting. 

• Depending on your health history, insurers may charge higher premiums or decline to cover you. This is why the original enrollment window matters so much, and why understanding your state's rules is a critical part of your planning.

State-specific Medigap rules are one of the more complex areas of Medicare planning, and they continue to evolve as more states adopt new protections. 

SGIA Medicare Consulting stays current on the rules in your area and can help you understand what options are available to you, regardless of your state.