Medigap birthday rule states and how to find your right window

If your Medigap premium climbed again this year, you may not be stuck with it. Fifteen states let people who already hold a Medicare Supplement policy switch once a year without answering a single health question, and New Mexico joins them in 2027.

Where you go next depends on your situation. Already hold a policy in one of those states? The table in the next section gives your exact window. Not sure the rule covers the switch you want? Three restrictions decide that, and they are laid out below. Your state isn’t listed? Skip ahead — other routes exist, and one applies everywhere.

ℹ️ Financial Disclaimer: This article is educational and is not personalized insurance, tax, lending, investment, or debt-relief advice. Medicare Supplement rules are set by state insurance law and change during legislative sessions. Confirm your own eligibility with your state department of insurance or a licensed agent before applying, and consult a CPA or qualified attorney for questions about how coverage decisions affect your taxes or estate.

What the Medigap birthday rule actually does

The birthday rule is a state-created annual window in which someone who already has a Medigap policy can move to another one without medical underwriting — no health questions, no denial for pre-existing conditions.

Your one federal window, and why it closed

Federal law gives most people a single protected shot at Medigap. The Medigap open enrollment period runs six months and begins once you are at least 65 and enrolled in Medicare Part B. Both conditions must be met for the clock to start.

After it closes, insurers in most states may underwrite your application. The birthday rule is a state exception carved into that federal default — not a Medicare benefit.

Why this is not the October-to-December enrollment period

The annual period running October 15 to December 7 covers Medicare Advantage and Part D, not Medigap. Confusing the two is the most common reason people miss their actual window. The dates that govern each Medicare enrollment period are worth checking separately.

🔍 How It Works: Medigap letters are standardized, so a Plan G bought from one insurer covers exactly what a Plan G from another covers. Only the premium differs. That is what makes a guaranteed-issue switch worth doing — you change the price, not the coverage.

Which states have a Medigap birthday rule

Fifteen states have a birthday rule in effect now. New Mexico enacted one in March 2026 that does not begin until January 1, 2027 — a distinction most published lists blur.

Verified September 15, 2026 against enacted state legislation and state insurance agency publications. Cells marked unconfirmed could not be verified to a state-level source; confirm those with your state department of insurance. State insurance law changes mid-session — your state’s insurance department is the controlling authority, not this table.

📊 Data Point: California’s window runs 60 days or more beginning on the individual’s birthday — not the first of the birth month, as several widely-read guides state. Source: California Senate Bill 407, enacted 2019, amending Health and Safety Code §1358.11(h)(1).

Three rules decide whether you can actually switch

Finding your state on the list is not the same as being able to make the switch you had in mind. Three restrictions compound, and a generous window is worthless if the other two are closed.

What opens your window

Most states start the clock on your birthday. Nevada starts it on the first day of your birth month. Oregon opens 30 days before your birthday, which means Oregonians can apply while still 64 days from their next renewal.

Which companies you can move to

California, Idaho, Oregon and others let you take your business anywhere. Illinois, Louisiana and West Virginia confine you to your current insurer or an affiliate. Utah confines you to your current insurer alone — which limits the rule to changing plans, not prices.

Which plan letters are open to you

Most states permit equal or lesser benefits. A Plan G holder may move to another Plan G or down to Plan N, but never up. Indiana, Kentucky and Virginia are narrower still: same letter only.

⚠️ Costly Mistake: Applying for a richer plan during your window does not get you a guaranteed-issue approval — it gets you underwritten. A Plan N holder reaching for Plan G is making an ordinary application, and a denial for health reasons is a real outcome. Check what separates Plan G from Plan N before you assume a move is lateral.

How to use your birthday window

The process is short, and the order matters more than the speed.

1. Confirm your exact dates with your state department of insurance before anything else — not from a broker’s summary.
2. Identify the letter you currently hold, then list only the letters your state permits you to move to.
3. Price that same letter across carriers your state allows.
4. Apply inside the window and tell the insurer you are using your state’s birthday rule provision.
5. Keep paying your current policy until the new one is issued in writing.

Oregon’s insurance division advises consumers not to cancel the current Medigap policy until the new one is issued, and notes that this may mean paying two premiums for a single month to keep the transfer clean. That overlap is the cost of never being uninsured.

✅ Action Step: Before you apply, call your State Health Insurance Assistance Program and ask one question: given my current plan letter and my state’s restriction, which specific plans am I eligible to switch to during my window? The counseling is free and the counselor earns nothing from your answer.

What if your state has no birthday rule

Most Americans live in the other 35 states. Several still have a guaranteed issue route.

New York and Connecticut require insurers to accept Medigap applicants year-round. Massachusetts runs an annual window each February and March. Missouri ties its window to your policy anniversary rather than your birthday — a distinction that gets it wrongly listed as a birthday-rule state.

Everywhere else, federal protection comes from the situations CMS enumerates — losing employer coverage, an insurer leaving your area, and a small number of others. The trial right for people moving back from Medicare Advantage is the one most people qualify for and least often use. You can verify your own case against the guaranteed issue situations Medicare publishes.

Mistakes that cost people their window

Trusting a state list nobody checked

Published lists disagree with each other and with the underlying law. Checking them against statute and state agency documents this month turned up errors on two of the highest-traffic states, including on pages ranking at the top of search results.

Assuming a rule applies before it does

New Mexico’s law is enacted but not operative until 2027. West Virginia requires 24 months on your current policy first. Illinois stops at age 75.

💡 Expert Note: Oregon’s own fact sheet limits the rule to policies issued after January 1, 1990 and excludes self-funded employer group plans — conditions absent from nearly every secondary summary. Read your state’s document, not a description of it.

Common questions about Medigap birthday rules

Your window is a date, and dates pass. Find your state in the table, confirm it against your own insurance department, and know which letters you may move to before you price anything. A free SHIP counselor will verify all three in one phone call.

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