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The ‘birthday rule’: a gift to Medigap enrollees?

Medicare supplement plan changes are limited, but 15 states offer Medigap enrollees special enrollment – and eight do it with a 'birthday rule'

Tanya Feke, M.D. | December 3, 2024

Medicare enrollees have an annual opportunity to review and adjust their Medicare coverage each year, but that flexibility doesn’t apply to Medicare supplement plans – commonly referred to as Medigap. While Medicare Advantage and Medicare Part D have an annual open enrollment period (October 15 – December 7), federal rules only give Medicare beneficiaries one guaranteed-issue Medigap open enrollment period in their lifetime.

Medigap plans help to pay down costs that Original Medicare doesn’t cover – costs such as deductibles, copays, and coinsurance. Depending on your medical situation, you could need more or less coverage at different times in your life. Unfortunately, having only one Medigap open enrollment period does not give enrollees the flexibility to change plans if they have pre-existing medical conditions.

The truth is that you may or may not be able to change Medigap plans when you need to. That’s because insurance companies can use medical underwriting when you apply for a Medigap plan outside of the Medicare open enrollment period.

All enrollees get a single Medicare open enrollment period

Medigap open enrollment starts the day your Medicare Part B coverage begins and lasts six months. This generally applies to Medicare beneficiaries 65 and older – although some states allow Medicare beneficiaries under 65 to sign up for Medigap plans, too (in that case, the beneficiary will also have another guaranteed-issue open enrollment window for Medigap when they turn 65, under federal rules).

This enrollment period is the one time that qualifying Medicare beneficiaries can sign up for a Medicare supplement plan without medical underwriting. Put simply, it is a time when insurance companies cannot charge you higher rates for any pre-existing conditions you have. In addition, carriers can’t make you wait for their plan’s benefits to kick in.

Signing up for Medigap outside of that window could cost you a lot more. In some cases, insurance carriers could deny you coverage altogether.

To clarify, you can apply for a Medigap policy at any time as long as you have Medicare Part A and Part B. If you’re subject to underwriting — which will generally be the case in most states if you’re past your initial enrollment period and don’t qualify for a special enrollment period — the insurer will determine whether to offer you coverage, and at what price, based on your medical history. So some people will have no trouble switching Medigap plans, while others will find it expensive or impossible.

Fortunately, there are Medigap protections in place that may qualify you for a special enrollment period. Your birthday may be one of them.

Some enrollees may qualify for Medigap special enrollment

You may qualify for a special Medigap enrollment period if you have guaranteed issue rights. In these cases, insurance companies cannot charge you more based on your medical conditions, put a waiting period on your coverage, and deny you coverage.

The Centers for Medicare and Medicaid has established a list of seven situations that require insurance companies to allow you to sign up for or change a Medigap plan without medical underwriting. This list of events is somewhat limited, but you may have even more options depending on what state you live in.

As of 2024, 15 states offer guaranteed issue rights that go above and beyond what the federal government does (this applies to annual enrollment or plan change opportunities; more than half the states go above and beyond federal requirements in terms of making guaranteed-issue Medigap plans available to beneficiaries under age 65).

A ‘birthday rule’ in eight states allows users to switch Medigap plans

Of those 15 states, eight have implemented a “birthday rule” that allows Medigap enrollees to switch Medigap plans without medical underwriting around the time of their birthday. (The other seven states have other windows, either year-round, or a specific time of the year, or related to the anniversary of when the person’s current policy was purchased.) To qualify for a “birthday rule” plan change, you need to already be enrolled in a Medigap plan.

  • California: You have 60 days from the first day of your birth month to change to another Medigap plan with the same level or a lower level of benefits. You can also change insurance carriers during this time. This is an updated birthday rule that took effect on January 1, 2020. Prior to that the special enrollment period was only 30 days long.
  • Idaho: You have 63 days from your birthday to change to another Medigap plan with the same level or a lower level of benefits. You can also change insurance carriers. This birthday rule starts on March 1, 2022.
  • Illinois: You have 45 days from your birthday to change to another Medigap plan with the same level or a lower level of benefits. This only applies to plans with your current insurance carrier pr an affiliate of your current insurer (the addition of affiliate insurers was due to legislation that Illinois enacted in 2024).1 To qualify for this birthday rule, you must be 65 to 75 years old. This birthday rule took effect on January 1, 2022.
  • Maryland: You have 30 days from your birthday to switch to another Medigap plan with equal or lesser benefits than your current Medigap plan. This birthday rule took effect on July 1, 2023.
  • Oregon: You have 30 days from the first day of your birth month to change to another Medigap plan with the same level or a lower level of benefits. You can also change insurance carriers. This birthday rule took effect on January 1, 2013.
  • Nevada: You have 60 days from the first day of your birth month to change to another Medigap plan with the same level or a lower level of benefits. You can also change insurance carriers. This birthday rule took effect on January 1, 2022.
  • Louisiana: You have 63 days from the date of your birthday to select a different Medigap plan with equal or lesser benefits. This only applies to plans with your current insurance carrier (or affiliates of your current insurer, under legislation that was enacted in 2023).
  • Kentucky: Legislation enacted in 2023 allows a Medigap enrollee to switch to another insurer’s Medigap policy (same benefits as the plan they already have) within 60 days of their birthday. This birthday rule took effect on January 1, 2024.

If you live in one of these states, you may want to take advantage of these birthday rules as long as you understand how they work.

Are ‘birthday rules’ likely in more states?

While Medigap is an excellent option for people on Original Medicare, some policyholders may feel that they are locked into Medigap plans with high rates. Guaranteed issue rights can help, but the situations outlined by CMS are limited to very specific situations that apply to relatively few policyholders.

The states that have created annual windows during which enrollees have at least some level of guaranteed-issue Medigap rights are helping to give Medicare beneficiaries the option to periodically review their Medigap options, even if they have pre-existing medical conditions.

The number of states offering “birthday rule” plan change windows has increased in recent years. Kentucky is the latest state to join this list, with a plan change opportunity that became available starting in 2024.

And “birthday rule” legislation was introduced in Michigan in late 2024 that would allow Medigap enrollees a 60-day window following their birthday, when they could switch to the same Medigap plan offered by another insurer.2 (The Michigan legislation would also significantly expand access to Medigap plans for disabled beneficiaries under the age of 65.)

Several other states considered legislation in 2024 to create birthday rules, but the bills did not pass:

  • South Dakota: Legislation (H.B.1108) would have allowed a Medigap enrollee to switch to a different plan with equal or lesser benefits during a 30-day window that starts on their birthday.3
  • Wisconsin: Legislation (S.B.412) would have allowed a Medigap enrollee to switch to a different plan with equal or lesser benefits during a 30-day window that starts on their birthday.4
  • Iowa: Legislation (S.F.2081) would have given any Medicare beneficiary in Iowa access to a guaranteed-issue window for Medigap plans during a 30-day window each year that begins on the person’s birthday. The text of the legislation did not restrict this to people who currently have Medigap, nor did it place any restrictions on the policy options that would be available during this window.5 Previous efforts to implement an annual enrollment window for Medigap in Iowa, including 2023’s H.F.228 and H.F.462, were also unsuccessful.6
  • Vermont: Legislation (S.230) would have created a Medigap guaranteed-issue window — running for 60 days following the beneficiary’s birthday — for beneficiaries switching from Medicare Advantage to Original Medicare.7 The federal government ensures guaranteed-issue access to Medigap for people in this scenario who are within their first 12 months of having Medicare Advantage coverage (trial right)8 but the Vermont legislation did not call for any time limit on the availability of the guaranteed-issue right it would create.

Although the bills in those four states were unsuccessful in 2024, those lawmakers may try again in a future year. Michigan’s legislation might pass, and other states might consider this as well. Keep an eye out for more “birthday rules” in the future.


Tanya Feke, M.D. is a licensed, board-certified family physician living in New Hampshire. As a practicing primary care physician in Connecticut and an urgent care physician in New Hampshire, she saw first-hand how Medicare impacted her patients. In recent years, her career path has shifted to consultant work with a focus on utilization review and medical necessity compliance. 

Dr. Feke is an expert in the field, having Medicare experience on the frontlines with both patients and hospital systems. To educate the public about ongoing issues with the program, she authored Medicare Essentials: A Physician Insider Reveals the Fine Print. Her analysis of Medicare issues is frequently referenced by the media and she is a contributor to multiple online publications. As founder of Diagnosis Life, LLC, she also posts regular content about health and wellness to her site at diagnosislife.com.

Footnotes
  1. Illinois Senate Bill 56 BillTrack50. Enacted May 9, 2024. 
  2. Michigan Senate Bill 1143” BillTrack50. Introduced Nov. 26, 2024 
  3. South Dakota House Bill 1108. BillTrack50. Accessed June 27, 2024 
  4. Wisconsin Senate Bill 412. BillTrack50. Accessed June 27, 2024 
  5. Iowa S.F.2081. BillTrack50. Accessed June 27, 2024 
  6. Iowa H.F.228 and Iowa H.F.462. BillTrack50. Accessed January 2024 
  7. Vermont S.230” BillTrack50. Accessed June 27, 2024. 
  8. Learn How Medigap Works” Medicare.gov. Accessed February 19, 2024. 
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