By Christian BrinkleyLicensed NC Insurance Agent, NPN 22217190, NC Life & Health · Updated October 14, 2026 · 4 min read
Most of the time, insurance companies can ask you health questions before selling you a Medigap policy. They can look at your medical history. They can charge you more or refuse you based on your health. That process is called medical underwriting. But there are specific windows when they cannot do any of that. During those windows, the company must sell you the policy, must cover your pre-existing conditions (with limited exceptions), and cannot charge you more because of your health. Those windows are called guaranteed issue rights. Knowing them can save you thousands of dollars a year.
The Medigap Open Enrollment Period
Your biggest guaranteed issue right comes when you first turn 65. If you enroll in Medicare Part B at 65, you get a six-month Medigap open enrollment period that starts the first day of the month you turn 65 and are enrolled in Part B.
During this window, you can buy any Medigap policy sold in your state. No health questions. No medical exam. The company cannot deny you or charge you extra because of your health. This is the one time the choice is fully yours.
Guaranteed Issue Rights: What Triggers Them
Beyond the initial open enrollment, federal law gives you guaranteed issue rights in specific situations. These are sometimes called Medigap protections. The main ones:
Your Medicare Advantage plan leaves Medicare or stops serving your area. If your plan exits the market or you move out of its service area, you get a guaranteed issue right to buy a Medigap policy.
The Birthday Rule: Which States Have It
Federal guaranteed issue rights are narrow. They only help in specific events. But some states give you a yearly opportunity to switch Medigap plans without underwriting. The most common version is called the birthday rule.
Under a birthday rule, you get a window around your birthday each year, usually 30 to 60 days, when you can switch to an equal or lesser Medigap plan without medical underwriting. You cannot upgrade to a richer plan, but you can switch companies or move to a plan with fewer benefits, often at a lower price.
What Guaranteed Issue Does Not Do
Guaranteed issue rights have limits. Know them before you count on one.
They do not apply in every situation. Wanting a cheaper plan because yours got expensive is not a guaranteed issue trigger under federal law. That is exactly why the state birthday rules matter so much. They cover the everyday situation the federal rules ignore.
They may not give you every plan. In some guaranteed issue situations, the company only has to offer you certain plan letters, not the full menu. During your initial open enrollment at 65, you get the full menu. In later guaranteed issue situations, the options may be narrower.
Practical Steps
If you are turning 65, your job is simple. Use your open enrollment period. Shop every plan letter available in your state. Pick the plan you can live with for years, because switching later may require underwriting.
If you are past 65 and on a Medigap plan, find out whether your state has a birthday rule, an anniversary rule, or year-round guaranteed issue. Write down your window. When it opens, compare prices. A 10-minute comparison could cut your premium.
The Bottom Line
Guaranteed issue rights are narrow federal windows plus a patchwork of state rules like the birthday rule. The strongest protection you get is your initial six-month open enrollment at 65. After that, your state rules and the federal triggers are what stand between you and medical underwriting.
This article is for general information only and is not legal, tax, or insurance advice. Medicare and Medigap rules vary by state and change over time. For free, unbiased help, contact your State Health Insurance Assistance Program (SHIP), call 1-800-MEDICARE, or talk with a local licensed insurance agent who can review your specific situation.
Questions people ask me about this
What is the Medigap open enrollment period?
Your biggest guaranteed issue right comes when you first turn 65. If you enroll in Medicare Part B at 65, you get a six-month Medigap open enrollment period that starts the first day of the month you turn 65 and are enrolled in Part B. During this window, you can buy any Medigap policy sold in your state. No health questions.
What guaranteed issue does not do?
Guaranteed issue rights have limits. Know them before you count on one. They do not apply in every situation. Wanting a cheaper plan because yours got expensive is not a guaranteed issue trigger under federal law. That is exactly why the state birthday rules matter so much. They cover the everyday situation the federal rules ignore.
What should I know about guaranteed issue rights?
Beyond the initial open enrollment, federal law gives you guaranteed issue rights in specific situations. These are sometimes called Medigap protections. The main ones: Your Medicare Advantage plan leaves Medicare or stops serving your area.
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