If you have a Medicare Supplement (Medigap) policy, you may be paying more than you need to. Medigap plans with the same letter cover the exact same benefits by law — a Plan G is a Plan G no matter which company sells it — but prices for identical coverage can vary a lot between insurers, and they tend to rise over time. The catch is that switching normally requires medical underwriting, so a health condition could get you turned down.
That is where the birthday rule comes in. In a growing number of states, you get a yearly window around your birthday to switch Medigap plans without any health questions. Here is how it works and where it applies in 2026.
What the Birthday Rule Is
The Medigap birthday rule is a state-level consumer protection. If you already have a Medigap policy, it gives you a set period each year — tied to your birthday — to move to another Medigap plan of equal or lesser benefits without going through medical underwriting. Because insurers cannot ask about your health during the window, a pre-existing condition cannot be used to deny you or charge you more.
The rule was created so people are not "locked in" to an overpriced policy simply because their health changed after they first enrolled. It rewards shopping around.
How It Works
The mechanics are similar from state to state, with important differences in the details:
- You must already have a Medigap plan. The birthday rule is for switching, not for buying your first policy.
- Equal or lesser benefits. You can generally move to the same plan letter or a plan that covers less — not to a richer plan.
- No health questions. During the window, the insurer cannot underwrite you.
- A limited window. Depending on the state, the window runs anywhere from about 30 to 63 days around your birthday.
Which States Have a Birthday Rule in 2026
As of 2026, roughly 15 to 16 states have adopted some form of the birthday rule or a similar annual switching protection. The list has been growing:
- Longer-standing rules: California, Oregon, Idaho, Illinois, Nevada, Louisiana, Oklahoma
- More recent additions: Kentucky and Maryland
- New for 2026: Delaware and Indiana (effective January 1, 2026) and West Virginia (effective June 11, 2026)
Separately, a few states — such as New York, Connecticut, Maine, and Massachusetts — offer year-round guaranteed-issue Medigap protections, which can be even more flexible than a birthday-rule window.
State-by-State Windows (Examples)
The exact window length and rules differ by state. Here are several well-established examples to show how much they can vary:
| State | Window | Key Rule |
|---|---|---|
| California | 60 days starting on your birthday | Equal or lesser benefits; any carrier |
| Oregon | 31 days starting on your birthday | Equal or lesser benefits |
| Idaho | 63 days starting on your birthday | Same plan letter only |
| Illinois | 45 days starting on your birthday | Ages 65-75; equal or lesser benefits |
| Nevada | 60 days from the first day of your birth month | Equal or lesser benefits |
| Louisiana | 93 days (30 days before to 63 days after) | Equal or lesser; same carrier only |
Because these terms change and new states keep joining, treat this table as a snapshot, not a guarantee. Always verify your state's current rule before you plan a switch.
Not Sure What Your Options Are?
Answer 6 quick questions and a licensed Medicare advisor can review your situation, check what plans are available where you live, and explain your rights — at no cost to you.
Check My EligibilityBirthday Rule vs. Guaranteed Issue vs. Open Enrollment
These three protections are easy to mix up:
- Medigap Open Enrollment — a one-time, six-month window when you first enroll in Part B at 65 or older, during which you can buy any Medigap plan with no underwriting.
- Guaranteed issue — triggered by specific events (like your Medicare Advantage plan terminating). See our guide on what to do if your plan is ending.
- Birthday rule — a recurring, annual window in certain states to switch to equal or lesser Medigap coverage without underwriting.
How to Use the Birthday Rule
- Confirm your state has it and note your exact window and its rules (same letter vs. equal-or-lesser, same carrier vs. any carrier).
- Know your current plan letter so you can compare apples to apples.
- Compare prices for the same or lesser coverage from other insurers.
- Apply within the window — do not let your birthday window lapse.
- Do not cancel your old plan until the new one is confirmed active, so you never have a coverage gap.
A licensed Medicare advisor can confirm whether your state has a birthday rule, tell you your exact window, and compare same-coverage prices for you — at no cost. If you are in a birthday-rule state, this is one of the easiest ways to lower your premium without giving up any benefits.