Michigan Medicare Supplement underwriting rules: no birthday rule, no safety net, and what that means for you

Michigan has no birthday rule. No annual Medigap open enrollment. No state-mandated carrier that must accept you year-round. When your initial six-month window closes, the Michigan Medicare Supplement underwriting rules leave you with one path to a new Medigap plan: pass medical underwriting — or qualify for a narrow set of federal guaranteed issue rights.

The Michigan legislature introduced birthday rule legislation in mid-2025, and similar legislation was introduced in late 2024. Neither has passed as of this writing. Until something changes, Michigan follows federal rules only — putting it in the same category as Texas, Georgia, North Carolina, and Virginia.

Compare that to New York and Connecticut, where residents can switch Medigap plans any day of the year with no health questions. Or Indiana, which added a birthday rule in 2026 giving residents a 60-day annual switching window. Michigan offers none of these protections — yet. Here’s exactly how the Michigan Medicare Supplement underwriting rules work and how to navigate them.

Your one guaranteed window: the 6-month open enrollment period

Like every state, Michigan residents get a one-time, six-month Medigap Open Enrollment Period. It starts the first day of the month you turn 65 and are enrolled in Medicare Part B. During this window, the Michigan Medicare Supplement underwriting rules work entirely in your favor:

• Insurance companies must sell you any Medigap plan they offer in Michigan
• They cannot ask health questions or request medical records
• They cannot deny your application for any reason
• They cannot charge you more because of pre-existing conditions
• They cannot impose a waiting period for pre-existing conditions if you had prior creditable coverage

This is the single most important enrollment window in your Medicare life in Michigan. Every plan letter is available. Every carrier must accept you. Your health doesn’t matter. Once this six-month window closes, the rules shift — and they don’t shift back.

What happens after the window closes

Once your six-month Medigap Open Enrollment Period ends, the Michigan Medicare Supplement underwriting rules shift to the carrier’s advantage. If you want to buy a new Medigap plan or switch from one carrier to another, insurance companies in Michigan can:

• Ask detailed health questions — current medications, recent hospitalizations, diagnoses, and upcoming procedures
• Request and review your medical records
• Deny your application based on health conditions
• Charge higher premiums based on your health status — preferred, standard, or substandard tiers
• Impose waiting periods for pre-existing conditions

The good news: according to industry data, roughly 75% of underwritten Medigap applications do get approved. But approval isn’t guaranteed, and conditions like cancer, heart disease, COPD, diabetes with complications, or recent surgeries can result in denial. In Michigan, with no birthday rule or annual open enrollment to fall back on, a denial can mean you’re locked into your current plan — or locked out of Medigap entirely.

Federal guaranteed issue rights in Michigan

Even without state-level protections, federal law provides guaranteed issue rights in specific situations. In these cases, Michigan carriers must sell you a Medigap plan without medical underwriting. You have 63 days from the qualifying event to apply.

Loss of employer or retiree coverage

If your employer-sponsored health plan or retiree coverage that supplements Medicare ends — whether through layoff, retirement, or the company dropping the plan — you have a guaranteed issue right. This is one of the most common paths to Medigap outside of the initial window, especially in Michigan where the auto industry’s retiree benefit changes have affected thousands of beneficiaries.

Medicare Advantage plan leaves your area or stops operating

If your MA plan exits your county or shuts down, you have the right to buy Medigap Plan A, B, D, G (or C, F if grandfathered), K, or L without underwriting.

12-month Medicare Advantage trial right

If you enrolled in a Medicare Advantage plan for the first time when you turned 65, you have a one-time, 12-month window to return to Original Medicare and buy a Medigap plan with no health questions. This is federal law. Once this window closes, it does not reopen.

Medigap carrier misled you or went bankrupt

If your Medigap insurance company violated its policy terms, misled you about coverage, or you lost your Medigap coverage through no fault of your own, you have a guaranteed issue right to buy a new plan.

Under-65 Medicare beneficiaries in Michigan

Michigan’s protections for under-65 Medicare beneficiaries are limited. If you’re under 65 and on Medicare due to disability, your Medigap choices are generally restricted to Plan A or Plan C (reassigned to Plan D for those newly eligible after January 1, 2020). Only a limited number of carriers are required to offer these plans to under-65 enrollees, and those carriers are allowed to charge significantly higher premiums.

Legislation introduced in mid-2025 would, if enacted, make all Medigap plans guaranteed issue for under-65 beneficiaries at the same rates charged to 65-year-olds. But similar legislation was introduced in late 2024 and did not advance. As of this writing, the bill is still under consideration. If you’re under 65 and on Medicare in Michigan, your options are narrow — contact me for current carrier quotes, as availability and pricing vary significantly.

How Medigap pricing works in Michigan

Michigan allows carriers to use any of the three standard pricing methods:

• Attained-age rating — the most common in Michigan. Your premium is based on your current age and increases every year as you get older, on top of any carrier-wide rate increases. Cheapest at 65, most expensive long-term.
• Issue-age rating — your premium is set based on your age when you first buy the policy. Doesn’t increase with age, though inflation adjustments still apply. More predictable over time.
• Community rating — everyone pays the same premium regardless of age. Most stable, but uncommon in Michigan. Required by law in states like New York and Connecticut, but in Michigan it’s up to the carrier.

Because Michigan has no birthday rule or annual switching window, your initial carrier choice carries extra weight. A carrier with aggressive rate increases can cost you significantly more over a decade — and without a protected switching period, escaping to a competitor means passing medical underwriting. Choose your carrier with the long game in mind.

The pending birthday rule legislation

Michigan lawmakers have introduced legislation that would create a birthday rule allowing Medigap enrollees to switch to the same plan offered by a different carrier without medical underwriting. The bill would also expand access for under-65 beneficiaries. As of early 2026, the legislation is still under consideration and has not been enacted.

If Michigan does adopt a birthday rule, it would likely function similarly to Indiana’s version — same plan letter, different carrier, within a limited window around your birthday. But until it passes, the Michigan Medicare Supplement underwriting rules remain federal-only. Plan as though the birthday rule won’t arrive in time for your next enrollment decision.

Michigan Medicare Supplement underwriting rules at a glance

Major Medigap carriers active in Michigan

Michigan has a competitive Medigap market. Because plan benefits are federally standardized — every Plan G covers the exact same things regardless of carrier — the differences come down to premium, rate stability, customer service, and financial strength. Active carriers in Michigan include:

• AARP / UnitedHealthcare
• Blue Cross Blue Shield of Michigan
• Mutual of Omaha
• Cigna
• Aetna
• Transamerica
• Philadelphia American

Premiums for the same Plan G can vary by 20% or more between carriers in the same ZIP code. An independent advisor appointed with multiple carriers can show you all options side by side — something a carrier-employed agent cannot do.

How to protect yourself in a state with no birthday rule

1. Get the right plan during your initial window

Because switching later requires underwriting in Michigan, your initial enrollment decision is effectively permanent for many people. Don’t choose the cheapest plan if it doesn’t match your needs — you may not be able to upgrade later. For most Michigan residents, Plan G offers the best balance of comprehensive coverage and reasonable premiums.

2. Choose your carrier for the long haul

Without a birthday rule, you may be with this carrier for decades. Look beyond today’s premium. Ask about five-year rate increase history, A.M. Best financial strength rating, and customer service reputation. A carrier that starts $15 cheaper but raises rates 12% annually will cost far more over time than a stable carrier with a slightly higher starting premium.

3. Understand the Medicare Advantage exit risks

If you choose Medicare Advantage over Original Medicare plus a supplement, know that returning to Medigap later will require medical underwriting in Michigan. Your 12-month trial right gives you one chance. After that, if your health has changed, you may not qualify for a Medigap plan at all. States like Florida, Ohio, and Pennsylvania face the same risk — this isn’t unique to Michigan, but it’s critical to understand before you decide.

4. Keep every piece of coverage documentation

If you ever need to exercise a federal guaranteed issue right, you’ll need proof. Keep letters from employers about plan terminations, Medicare Advantage plan exit notices, and all carrier correspondence. A missing document can delay or prevent a time-sensitive enrollment.

How Michigan compares to other states

Michigan sits in the group of states that follow federal rules without adding state-level protections. Texas, Georgia, North Carolina, Ohio, Pennsylvania, South Carolina, and Virginia are in the same position — once the initial window closes, underwriting applies.

Neighboring Indiana passed its birthday rule in 2025, effective January 2026, giving residents a 60-day annual window to switch carriers on the same plan letter. Illinois has a birthday rule for ages 65-75, though it’s limited to the same carrier family. Michigan has neither protection — and while legislation is pending, there’s no guarantee it will pass.

At the far end of the spectrum, New York and Connecticut offer year-round open enrollment with no underwriting at all — a level of consumer protection Michigan residents can only hope for.

For a full comparison of how every state where I’m licensed handles Medigap underwriting, see our Medicare Supplement Underwriting Rules by State guide.