Medicare Supplement Birthday Rule by State: Complete Guide to Switching Without Underwriting

The birthday rule gives Medicare Supplement (Medigap) policyholders in certain states an annual opportunity to switch plans without medical underwriting. This guide covers every state with birthday rule protections.

TL;DR Quick Answer

What is the Birthday Rule? A state law allowing existing Medigap policyholders to switch to a different plan around their birthday without answering health questions or facing medical underwriting.

States with Birthday Rules (2026):

• California - 30 days after birthday, switch to same or lesser-benefit plan
• Oregon - 30 days after birthday, switch to same or lesser-benefit plan
• Nevada - 30 days after birthday, switch to same or lesser-benefit plan (age 65+)
• Illinois - 45 days after birthday, switch to Plan A from any insurer

Key Benefit: If your health has declined since you bought your Medigap policy, the birthday rule lets you shop for better rates without risking denial.

Use our Medicare Supplement Penalty Calculator to compare plan costs before switching.

Detailed State-by-State Guide

California Birthday Rule

California has the most widely used birthday rule in the nation.

Eligibility:

• Must already have a Medigap policy
• Must be within 30 days after your birthday
• Age 65 or older

What You Can Do:

• Switch to the same plan letter from a different insurance company (e.g., Plan G to Plan G)
• Switch to a lesser-benefit plan (e.g., Plan G to Plan N)

What You Cannot Do:

• Switch to a higher-benefit plan (e.g., Plan N to Plan G requires underwriting)
• Switch if you don’t already have a Medigap policy

Example: Your birthday is March 15. You have until April 14 to apply for a new Medigap plan with guaranteed issue rights under the birthday rule.

Oregon Birthday Rule

Oregon’s birthday rule is nearly identical to California’s.

Eligibility:

• Existing Medigap policyholder
• Within 30 days after your birthday
• Age 65 or older (or disabled and eligible for Medicare)

What You Can Do:

• Switch to the same or lesser-benefit plan
• Change insurance companies without health questions

Key Difference from California: Oregon also applies the birthday rule to disabled Medicare beneficiaries under 65.

Nevada Birthday Rule

Nevada offers birthday rule protections with slightly different parameters.

Eligibility:

• Existing Medigap policyholder
• Within 30 days after your birthday
• Age 65 or older

What You Can Do:

• Switch to the same plan letter from any insurer
• Switch to a plan with equal or lesser benefits

Restriction:

• Only available to those age 65 and older
• Disabled beneficiaries under 65 are not covered

Illinois Birthday Rule

Illinois has the most limited birthday rule.

Eligibility:

• Existing Medigap policyholder
• Within 45 days after your birthday
• Age 65 or older

What You Can Do:

• Switch to Plan A only from any insurance company
• No health questions asked

Limitations:

• Only Plan A is available (most basic coverage)
• Cannot switch to other plan letters
• Plan A has fewer benefits than most other plans

Birthday Rule Comparison Table

State	Window	Plans Available	Age Requirement
California	30 days after birthday	Same or lesser benefit	65+
Oregon	30 days after birthday	Same or lesser benefit	65+ or disabled
Nevada	30 days after birthday	Same or lesser benefit	65+
Illinois	45 days after birthday	Plan A only	65+

How to Use the Birthday Rule

Step-by-Step Process

1. Mark Your Calendar - The window opens on your birthday and closes 30-45 days later (depending on state)

2. Shop for Quotes - Compare rates from multiple insurers for your target plan

3. Apply During the Window - Submit your application within the birthday rule timeframe

4. Disclose Birthday Rule - Tell the insurance agent you’re applying under your state’s birthday rule

5. Keep Current Coverage - Don’t cancel your existing policy until the new one is approved

6. Verify Approval - Get written confirmation before disenrolling from your old plan

What Documents You Need

• Proof of current Medigap coverage (policy number, effective date)
• Medicare card showing Part A and Part B effective dates
• Driver’s license or state ID (proof of age and residency)
• Birth certificate may be required in some cases

Birthday Rule vs. Other Guaranteed Issue Rights

The birthday rule is just one way to switch without underwriting. See how it compares:

Situation	Timeframe	Plans Available
Medigap Open Enrollment	6 months after Part B	All plans (A-N)
Birthday Rule (CA/OR/NV)	30 days after birthday	Same or lesser benefit
Birthday Rule (IL)	45 days after birthday	Plan A only
Losing Employer Coverage	63 days	Plans A-L
Year-Round GI (CT/MA/NY/VT)	Anytime	All available plans

For a complete overview of guaranteed issue situations, see our Medigap Guaranteed Issue Rights by State guide.

States Without Birthday Rules

If you live in a state without a birthday rule, your options to switch without underwriting are limited to:

1. Medigap Open Enrollment - Only happens once, 6 months after Part B starts
2. Federal Guaranteed Issue Events - Losing coverage, moving, MA plan leaving area
3. State-Specific Protections - Some states have annual enrollment windows instead

States with Alternative Protections:

• Missouri: Annual enrollment window (Jan 1 - Feb 28)
• Maine: Annual guaranteed issue period (Jan 1 - Mar 1)
• Washington: Plan G switching during annual window

For a complete switching checklist, see our Medicare Supplement Switching Rules Checklist.

Common Mistakes to Avoid

Mistake 1: Missing the Window

The birthday rule window is short (30-45 days). Mark your calendar and start shopping before your birthday arrives.

Mistake 2: Applying for the Wrong Plan

In California, Oregon, and Nevada, you can only switch to the same plan letter or a lesser-benefit plan. Applying for a better plan will trigger medical underwriting.

Mistake 3: Canceling Too Early

Never cancel your existing policy until the new one is approved in writing. A gap in coverage could leave you unprotected.

Mistake 4: Assuming All States Have It

Only four states have birthday rules. Don’t assume you have this protection without verifying your state’s laws.

Mistake 5: Not Disclosing the Birthday Rule

Always tell the insurance agent you’re applying under the birthday rule. Otherwise, they may process your application with full underwriting.

Birthday Rule Checklist

• Verify your state has a birthday rule
• Mark your birthday on the calendar
• Calculate your deadline (30 or 45 days after)
• Shop for quotes 2-3 weeks before birthday
• Confirm which plans are available (same/lesser or Plan A)
• Gather required documents
• Apply within the birthday window
• Disclose birthday rule to the agent
• Wait for approval before canceling old policy
• Get written confirmation of new policy

Frequently Asked Questions

Can I use the birthday rule if I have Medicare Advantage?

No, the birthday rule only applies to switching between Medigap plans. If you have Medicare Advantage and want to switch to Medigap, you’ll need to use your Medigap Open Enrollment Period or a guaranteed issue event like the Medicare Advantage trial right.

Can I use the birthday rule every year?

Yes, in states with birthday rules, you can use this protection annually. Each year around your birthday, you have a new window to switch Medigap plans without medical underwriting.

Does the birthday rule apply if I move to another state?

The birthday rule is based on your state of residence when you apply. If you move from a state with a birthday rule to one without it, you lose this protection. However, moving to a new state can create its own guaranteed issue rights for 63 days.

What if my birthday is February 29?

In non-leap years, February 29 birthdays are typically treated as March 1 for the birthday rule. Check with your state insurance department for specific guidance on leap year birthdays.

Can insurance companies charge more under the birthday rule?

Insurance companies cannot deny coverage or charge higher premiums based on health conditions during the birthday rule window. However, they can charge their standard rates, which is why it’s important to compare quotes from multiple insurers.

Disclaimer

This article is for educational purposes only and does not constitute legal, financial, or insurance advice. Medicare rules and state regulations change frequently. Always verify current rules with your state insurance department and Medicare.gov before making enrollment decisions. Consult a licensed insurance agent for personalized guidance.

Related Resources

• Medigap Guaranteed Issue Rights by State
• Medicare Supplement Switching Rules Checklist
• Best Time to Buy a Medigap Policy
• Medicare Supplement Penalty Calculator

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