Medicare Supplement

Switching Medigap in University City: the federal rights, state add-ons, and underwriting question

UNIVERSITY CITY, Mo. — If you already have a Medicare Supplement (Medigap) policy and you're wondering whether you can move to a different one, the answer is usually "yes, but it depends." Unlike Medicare Advantage and Part D, Medigap doesn't have one tidy fall enrollment window. Instead, your ability to switch — and whether the new insurer can ask health questions — turns on a mix of federal protections, a handful of state rules, and timing.

Here's how those pieces fit together for people on Medicare in University City, which sits in St. Louis County.

The one window where switching is easiest

Your best shot at switching Medigap without any health questions is your Medigap Open Enrollment Period. That's a six-month window that starts the month you're 65 or older AND enrolled in Medicare Part B. During this time, insurers must sell you any Medigap policy they offer at their best available rate, regardless of your health history.

This window happens once. If you're past it, the rules change.

What "medical underwriting" actually means

Outside that first six-month window — and outside a guaranteed-issue situation — most states allow insurers to use medical underwriting when you apply for a new Medigap policy. That means the company can:

• Ask detailed health questions
• Look at your prescriptions and medical history
• Charge you more, or deny coverage entirely, based on what they find

Underwriting doesn't mean you'll be turned down. Plenty of people switch successfully. But it's the reason experts say: don't cancel your current policy until you've been approved for the new one.

Federal guaranteed-issue rights

Federal law gives you "guaranteed-issue" rights — the right to buy certain Medigap policies without medical underwriting — in specific situations. According to CMS, these include cases such as:

• Your Medicare Advantage plan leaves your area or stops serving Medicare
• You move out of your plan's service area
• Your employer or union group coverage ends
• Your Medigap insurer goes bankrupt or misled you
• You joined Medicare Advantage when you first became eligible for Medicare, and want to switch back to Original Medicare within 12 months (a "trial right")

When one of these applies, you generally have 63 days to use the right, and only certain Medigap plans are available to you under it. The full list is on medicare.gov under "Medicare Supplement Insurance (Medigap)."

The state rules that some states add

Beyond the federal floor, some states have added their own protections. You may have heard of:

• Birthday rule — In a handful of states, you can switch to an equal or lesser Medigap plan without underwriting for a set number of days around your birthday each year.
• Anniversary rule — In a couple of states, a similar window opens around the anniversary of your policy.
• Continuous open enrollment / year-round guaranteed issue — A few states require insurers to sell Medigap to eligible people without health questions at any time, though rules on age and plan letters vary.

These rules differ from state to state, and they change. Rather than assume University City residents have one of these protections, the honest answer is: check before you count on it. Missouri's State Health Insurance Assistance Program — known here as CLAIM — and the Missouri Department of Commerce and Insurance can confirm which rules currently apply in this state and to your situation.

A quick word on timing with other Medicare dates

Medigap switching runs on its own clock, but a few Medicare dates still matter for planning:

• Annual Enrollment Period (Oct. 15 – Dec. 7): For Medicare Advantage and Part D changes, not Medigap.
• Medicare Advantage Open Enrollment (Jan. 1 – March 31): If you drop Medicare Advantage and return to Original Medicare during a trial right period, that may open a Medigap guaranteed-issue window.
• 2026 Part D numbers to know: The out-of-pocket cap is $2,100, and the maximum deductible is $615. The old coverage gap was eliminated in 2025. If you take a lot of medications, the optional Medicare Prescription Payment Plan lets you spread drug costs across the year.

None of these change Medigap rules directly, but they often prompt people to review everything at once.

Before you apply to switch

A few practical steps that apply no matter where you live:

1. Compare Medigap plan letters (A, B, G, N, etc.) — the letter defines the standardized benefits, not the insurer. 2. Ask the new insurer, in writing, whether you'll be underwritten. 3. Keep your current policy in force until the new one is approved and effective. 4. Confirm any state protection with CLAIM or the Missouri Department of Commerce and Insurance before relying on it.