Quick answer: A guaranteed issue right (Medicare also calls these Medigap protections) is a limited situation in which a Medigap insurance company must sell you a policy, must cover pre-existing conditions, and cannot charge you more because of past or present health problems. That is different from your six-month Medigap Open Enrollment Period, which generally starts when you are 65 or older and enrolled in Part B. Federal law lists specific guaranteed issue situations, such as certain losses of other coverage and trial rights after you try a Medicare Advantage Plan. Some states add extra consumer protections; Massachusetts, Minnesota and Wisconsin also use different standardized plan designs. If you do not have a guaranteed issue right or Medigap Open Enrollment, a company may be able to deny a policy or use medical underwriting. Confirm the situation and the application window on Medicare.gov and with your state insurance department. This explainer sits in our Medicare guide and pairs with Medicare Advantage vs Medigap.
Sources: Medicare.gov “Guaranteed issue rights” and “When can I buy Medigap”; Medicare.gov publication 02110, “Choosing a Medigap Policy” (federal GI situations, trial rights, 60-days-before / 63-days-after timing in common situations, plans generally available under federal GI, and state-variation note including Massachusetts, Minnesota and Wisconsin). State insurance departments may offer additional rights; those are not inventoried here as a national list. Checked November 2026. This is general consumer information, not legal, tax, medical or benefits advice. Medicare rules, plan designs and dollar amounts change. Confirm current details on Medicare.gov, with CMS, Social Security, your plan, and a State Health Insurance Assistance Program (SHIP) counselor before you rely on a figure or a deadline.
Open Enrollment, Guaranteed Issue and Ordinary Underwriting
Medigap (Medicare Supplement Insurance) works with Original Medicare. It does not work alongside a Medicare Advantage Plan. If you want a Medigap policy, you generally need Original Medicare (Part A and Part B). Plan comparisons such as Plan G vs Plan N help you see benefit differences among standardized plans, but those comparisons assume you can actually buy the policy.
Three different “can I buy this?” rules get confused:
- Medigap Open Enrollment is a one-time six-month period that, in official Medicare.gov language, generally begins when you are 65 or older and enrolled in Part B. During that period, companies that sell Medigap in your state cannot use medical underwriting to refuse you or charge you more because of your health.
- Guaranteed issue rights apply in limited situations outside that six-month window, usually after other coverage ends or after certain Medicare Advantage trial rights. Official materials say the company must sell you a policy, must cover pre-existing conditions, and cannot charge more because of health problems. The plans you can buy under a federal guaranteed issue right are a defined set, not always every plan letter a company sells.
- At other times, a company may be allowed to ask health questions, charge more, or refuse to sell a policy. Some states limit that underwriting. Federal law does not give you a year-round right to buy any Medigap plan at the same price regardless of health.
Missing a window can be expensive later, even if you can still buy a policy, because underwriting may apply. That is why the official dates on a termination notice matter more than a casual “you can always get a supplement.”
Medicare.gov and publication 02110 are the federal explanations to start with. Then check your state insurance department, because states can add rights (for example, some states have additional guaranteed issue or “birthday rule” policies). This article does not treat any one state’s extra rule as a national standard.
Common Federal Situations and Time Limits
Publication 02110 describes the most common federal guaranteed issue situations, the plans you generally have a right to buy, and when you must apply. The details are official and situation-specific, so read the current booklet rather than treating the summary below as a complete legal list.
One common cluster involves a Medicare Advantage Plan that is leaving Medicare, stopping care in your area, changing its service area because you moved, or having a significant network change — and you choose to switch to Original Medicare rather than another Advantage plan. Official materials describe an application window that can include up to 60 days before coverage ends or by the date in a termination notice, and no more than 63 days after coverage ends. Medigap coverage cannot start until the Advantage coverage ends.
Another common situation is Original Medicare plus an employer group health plan (including, in the official wording, retiree, COBRA or union coverage) that pays after Medicare, when that plan is ending. Official materials say you may apply no more than 63 days after the latest of the coverage-end date, the date on a notice that coverage is ending, or the date on a claim denial if that is how you learned coverage ended. If you have COBRA, official language says you can buy Medigap right away or wait until COBRA ends.
Trial rights are a separate and important protection. Official Medicare materials describe a 12-month trial right if you join a Medicare Advantage Plan for the first time (and, in a related rule, if you dropped a Medigap policy to do it). During that trial year you may be able to return to Original Medicare and buy a Medigap policy under guaranteed issue rules. If you joined an Advantage plan when you were first eligible for Medicare at 65, official materials describe a right to buy any Medigap policy sold in your state. If you dropped a Medigap policy to try Advantage, you can generally get the same policy back if the company still sells it; otherwise certain plans are available. Confirm the exact official wording for your enrollment history, because the plan letters you can buy can differ.
Under the federal situations described in the official booklet, the plans you can often buy are Medigap Plan A, B, C, D, F or G sold in your state, with official asterisks because Plans C and F are not available to people who became eligible for Medicare on or after January 1, 2020. Do not assume you can force a company to sell Plan N or Plan K under a federal guaranteed issue right. State rules can be broader.
Keep termination notices, plan letters and claim denials. Official timing often runs from those documents. A late application can mean the guaranteed issue right is no longer available.
Massachusetts, Minnesota and Wisconsin use different standardized Medigap designs. Official materials say people in those states still have guaranteed issue rights, but the policy choices look different. Use the state-specific pages in publication 02110 and your state insurance department.
What to Do If You Do Not Have a Guaranteed Issue Right
You can still ask companies whether they will sell you a policy. Some will, with or without underwriting, depending on the company and the state. Get quotes in writing, answer health questions accurately, and compare the same plan letter across companies. A company may also impose a waiting period for pre-existing conditions when guaranteed issue does not apply, within official limits. Ask before you drop other coverage.
If you are leaving a Medicare Advantage Plan and counting on a Medigap policy, confirm the right and the application window before you disenroll. The winter Medicare Advantage Open Enrollment Period can let you return to Original Medicare and join a drug plan; it does not, by itself, create a Medigap guaranteed issue right. Trial rights and other listed situations are what create that protection.
SHIP counselors and your state insurance department can review a termination letter with you. 1-800-MEDICARE can also help you find official publications. Beware of a pitch that says you “must” buy a particular policy this week if it does not match an official window.
Medigap premiums vary by company, age-rating or community-rating rules in your state, and discounts. This article does not invent a typical premium. Compare official plan benefits first, then price, and remember that you generally still pay your Part B premium.
Revisit official rules if you move to another state, because Medigap is state-regulated and guaranteed issue details can change with the move. If you lose other coverage, put a reminder on the 63-day clock described in official materials and do not wait for a second notice that may never come.
Documents, State Help and Timing Around Other Coverage
Guaranteed issue rights are paper-driven. The official clock in several federal situations runs from a coverage-end date, a termination notice, or a claim denial, so those pages belong in a folder before you start calling companies. If a Medicare Advantage Plan is leaving an area, the non-renewal letter is the document SHIP and an insurer will ask to see. If an employer or union plan is ending, the termination or COBRA notice plays the same role. A verbal statement that “coverage is wrapping up” is harder to use than a dated letter.
State insurance departments and SHIP counselors are the practical second stop after Medicare.gov and publication 02110. Ask two concrete questions: whether a federal guaranteed issue situation appears to fit the letter you have, and whether your state adds a broader right that the federal booklet does not list. Because this article does not inventory state extras, that local call is part of doing the work correctly, especially if you live in a state known for additional Medigap protections, or in Massachusetts, Minnesota or Wisconsin, where plan designs differ.
Compare the same official plan letter from more than one company when you have a right to buy that letter. Premiums can differ even when benefits are standardized. Ask about household discounts, smoking status rules, and payment-method discounts only as the company actually offers them, and get the offer in writing. Do not let a sales pitch substitute a different plan letter “because it is almost the same” if your guaranteed issue right is limited to a defined list.
If you are still inside the six-month Medigap Open Enrollment Period, that window may be broader than a later guaranteed issue right. People who delay a Medigap purchase after Part B starts can lose an easier path, even if a later guaranteed issue situation eventually appears. Calendar that six-month period when Part B begins, then treat later protections as backup, not as a reason to wait without a plan.
After a policy is issued, read the official outline of coverage, the start date, and any waiting-period language. Guaranteed issue rights, when they apply, include official pre-existing-condition protections described by Medicare.gov. Keep the application, the acceptance letter, and the first premium receipt with the termination notice that supported the right. Those are the documents a later dispute will need.
Frequently Asked Questions
Is a guaranteed issue right the same as Medigap Open Enrollment?
No. Open Enrollment is a one-time six-month window generally tied to turning 65 and enrolling in Part B. Guaranteed issue rights are limited later situations with their own application windows.
Can a company reject me if I have a guaranteed issue right?
Official Medicare.gov materials say that in a guaranteed issue situation the company must sell you a policy, must cover pre-existing conditions, and cannot charge you more because of health problems. The plans you can buy may still be a defined list.
Do all states follow the same Medigap plan letters?
Most states use the standardized A–N letter plans, but Massachusetts, Minnesota and Wisconsin have different designs. States can also add consumer protections beyond federal law.
If I leave Medicare Advantage in February, do I automatically get Medigap?
No. You need a guaranteed issue right, a trial right, Medigap Open Enrollment, a state protection, or a company willing to underwrite and issue a policy.
How long do I have to apply after other coverage ends?
In several common federal situations, official materials describe a window of no more than 63 days after coverage ends (or after a notice or claim denial, depending on the situation), and sometimes up to 60 days before coverage ends. Read the official situation that matches yours.
Can I buy Plan N under a federal guaranteed issue right?
Not necessarily. The federal list in publication 02110 commonly includes Plans A, B, C, D, F or G, with eligibility limits on C and F. Check the current official booklet and your state rules.
