Quick Answer
The Medigap birthday rule is a state-level consumer protection that gives Medicare Supplement enrollees a limited window each year - typically 30 to 63 days around their birthday - to switch to an equal or lesser Medigap plan without medical underwriting (no health questions). As of 2026, approximately 15 states have enacted some form of birthday rule or anniversary rule.
Coverage Comparison by Plan Type
| Plan Type | Coverage | Notes |
|---|---|---|
| Birthday Rule States | Annual window to switch Medigap plans without underwriting | ~15 states as of 2026; window is 30–63 days around birthday |
| Initial Enrollment Period (IEP) | 6-month guaranteed issue window when you first enroll in Part B | Federal right; available in all states; best time to enroll in Medigap |
| Guaranteed Issue Rights | Federal right to enroll without underwriting in specific situations | Triggered by plan termination, losing employer coverage, moving out of plan area |
| Non-Birthday Rule States | No annual switching window; medical underwriting required outside IEP | Most states; you can be denied or charged more based on health history |
Understanding Your Coverage Options
What is the Medigap Birthday Rule?
There is no federal annual open enrollment period for Medigap (Medicare Supplement) plans. Outside of your Initial Enrollment Period, insurers in most states can use medical underwriting - meaning they can charge you more or deny coverage based on your health history.
The Medigap birthday rule is a state-level protection that creates an annual window around your birthday during which you can switch to a Medigap plan with equal or lesser benefits without underwriting. This gives you the ability to shop for a lower premium each year.
What It Covers
- Switch to any Medigap plan with equal or lesser benefits without answering health questions
- Cannot be denied coverage or charged more due to pre-existing conditions during the window
- Window is typically 30–63 days starting on or around your birthday
- Available to current Medigap enrollees (not for first-time enrollment)
What It Doesn't Cover
- Cannot upgrade to a plan with more benefits (e.g., Plan N to Plan G) without underwriting
- Does not apply to Medicare Advantage plans
- Not available in states without a birthday rule
Equal or Lesser Benefits
Most birthday rule states limit switches to plans with equal or lesser benefits. For example, you can switch from Plan G to Plan G (same benefits, lower premium) or from Plan G to Plan N (lesser benefits). You generally cannot switch from Plan N to Plan G using the birthday rule.
States with the Medigap Birthday Rule (2026)
As of 2026, approximately 15 states have enacted a Medigap birthday rule or similar anniversary rule. The rules vary by state in terms of window length, eligible plans, and age restrictions.
What It Covers
- California: 60-day window starting on birthday; equal or lesser benefits; all ages
- Oregon: 31-day window starting on birthday; equal or lesser benefits; all ages
- Idaho: 63-day window starting on birthday; equal or lesser benefits; all ages
- Illinois: 45-day window from birthday; equal or lesser benefits; ages 65–75 only
- Nevada: 60-day window starting on birthday; equal or lesser benefits; all ages
- Louisiana: 30-day window starting on birthday; equal or lesser benefits
- Maryland: 31-day window starting on birthday; equal or lesser benefits
- Kentucky: 60-day window starting on birthday; equal or lesser benefits
- Indiana: 60-day window (effective January 1, 2026); equal or lesser benefits
- Delaware: Available as of January 1, 2026; check state rules for details
- Missouri, Wisconsin, New York, Massachusetts, Connecticut: Have continuous or open enrollment protections (not birthday-specific but similar effect)
What It Doesn't Cover
- Rules change frequently - always verify current state rules before switching
- Some states limit the birthday rule to specific age ranges
How to Use the Birthday Rule
Using the birthday rule is straightforward, but timing is critical. Missing your window means waiting another year or facing medical underwriting.
What It Covers
- Step 1: Confirm your state has a birthday rule and check the exact window dates
- Step 2: Shop for Medigap plans with equal or lesser benefits at a lower premium
- Step 3: Apply for the new plan during your birthday window
- Step 4: The new insurer cannot ask health questions or deny you during the window
- Step 5: Once approved, cancel your old plan (coordinate start/end dates carefully)
- Step 6: Do not cancel your old plan until the new one is confirmed in writing
What It Doesn't Cover
- Do not cancel your old plan before the new one is confirmed
- Missing the window means waiting until next year or facing underwriting
Shop 60–90 Days before Your Birthday
Start comparing Medigap plans 60–90 days before your birthday so you're ready to apply as soon as your window opens. Premiums for the same plan can vary significantly between insurers.
What If Your State Doesn't Have a Birthday Rule?
If you live in a state without a birthday rule, you can still switch Medigap plans, but you'll likely face medical underwriting. Insurers can ask health questions and may charge more or deny coverage based on your health history.
What It Covers
- Federal Guaranteed Issue Rights: Triggered by specific events (plan termination, losing employer coverage, moving out of MA plan area)
- Trial Right: If you tried Medicare Advantage for the first time, you have 12 months to switch back to Original Medicare and enroll in Medigap without underwriting
- Some states have continuous open enrollment or community rating that limits underwriting
- You can always apply for Medigap with underwriting - you may be approved even with health conditions
What It Doesn't Cover
- No guaranteed right to switch without underwriting in non-birthday-rule states
Medigap Birthday Rule: State Comparison
| State | Window Length | Starts | Age Limit | Benefit Restriction |
|---|---|---|---|---|
| California | 60 days | Birthday | None | Equal or lesser |
| Oregon | 31 days | Birthday | None | Equal or lesser |
| Idaho | 63 days | Birthday | None | Equal or lesser |
| Illinois | 45 days | Birthday | 65–75 | Equal or lesser |
| Nevada | 60 days | Birthday | None | Equal or lesser |
| Louisiana | 30 days | Birthday | None | Equal or lesser |
| Maryland | 31 days | Birthday | None | Equal or lesser |
| Kentucky | 60 days | Birthday | None | Equal or lesser |
| Indiana | 60 days | Birthday | None | Equal or lesser |
✦ Important Exceptions & Notes
Missouri Anniversary Rule
Missouri has an "anniversary rule" rather than a birthday rule. Missouri Medigap enrollees have a 30-day window each year on the anniversary of their plan enrollment date (not their birthday) to switch to an equal or lesser plan without underwriting.
States with Continuous Open Enrollment
New York, Massachusetts, Connecticut, and Maine have continuous open enrollment or community rating laws that provide broader protections than the birthday rule. In these states, insurers generally cannot use medical underwriting at all.
NY, MA, CT, and ME have stronger protections than the birthday rule.
Plan F and Plan C Availability
Plans F and C are only available to people who became eligible for Medicare before January 1, 2020. If you're using the birthday rule, you cannot switch to Plan F or C if you became Medicare-eligible on or after January 1, 2020.
Birthday Rule Does not Apply to Medicare Advantage
The Medigap birthday rule only applies to Medicare Supplement (Medigap) plans. It does not affect Medicare Advantage plan switching, which has its own Annual Enrollment Period (October 15 – December 7).
✦ Recent State Enactments (2025–2026)
Indiana Birthday Rule (Effective January 1, 2026)
PassedIndiana enacted a Medigap birthday rule effective January 1, 2026, giving enrollees a 60-day window around their birthday to switch to an equal or lesser plan without underwriting.
Delaware Birthday Rule (Effective January 1, 2026)
PassedDelaware enacted a Medigap birthday rule effective January 1, 2026. Check the Delaware Department of Insurance for specific window and eligibility details.
Additional States Considering Birthday Rule Legislation
ProposedSeveral additional states have introduced birthday rule legislation in 2025–2026 legislative sessions. Check your state's Department of Insurance for the latest status.
How to Maximize Your Birthday Rule Opportunity
The birthday rule is one of the best opportunities to lower your Medigap premium without risking your coverage. Here's how to make the most of it.
Birthday Rule Checklist
- Confirm your state has a birthday rule and check the exact window dates
- Start shopping 60–90 days before your birthday
- Compare premiums for the same or lesser plan across multiple insurers
- Apply for the new plan during your birthday window
- Get written confirmation of approval before canceling your old plan
- Coordinate start/end dates to avoid a gap in coverage
- Work with a licensed independent Medicare agent for unbiased comparison
✦ Frequently Asked Questions
David Haass
AuthorDavid Haass is a licensed insurance agent and Medicare specialist at MedicareFAQ.com.
Ashlee Zareczny
ReviewerAshlee Zareczny is the Compliance & Editorial Manager at MedicareFAQ.