Medicare Supplement

Medigap in Houma: how the standardized letters fill gaps

HOUMA, La. — If you've ever looked at an Original Medicare summary and wondered who picks up the leftover 20%, you're not alone. That gap is exactly what Medicare Supplement insurance — better known as Medigap — is built to help fill. And because Medigap plans are standardized by letter across most of the country, understanding how the letters work can save you a lot of confusion during shopping season.

Here's a plain-language guide to what Medigap does, what it doesn't, and how to think about it if you live in Houma or anywhere in Terrebonne Parish.

What Medigap is — and what it isn't

Medigap is private insurance you can buy to help pay some of the out-of-pocket costs that Original Medicare (Part A and Part B) leaves behind. That includes things like coinsurance, copays, and in some cases the Part A hospital deductible.

A few important things Medigap is not:

• It is not Medicare Advantage (Part C). You can't have both at the same time.
• It does not include prescription drug coverage. For that, you'd add a stand-alone Part D plan.
• It does not typically cover dental, vision, hearing aids, or long-term care.

In short, Medigap sits alongside Original Medicare. Medicare pays first, then your Medigap plan pays its share of what's left.

How the standardized letters work

This is where a lot of people get tripped up. Medigap plans are sold by private insurance companies, but the benefits inside each lettered plan are set by federal rules. That means a Plan G from one carrier covers the same core benefits as a Plan G from another carrier. What can differ is the price, the company's customer service, and how they handle rate increases.

The plans currently sold to new enrollees are labeled with letters: A, B, D, G, K, L, M, and N. Plans C and F are still held by people who had them before, but they're generally not available to people who became eligible for Medicare on or after January 1, 2020.

Each letter offers a different mix of coverage. For example, some cover the Part A hospital deductible in full, some cover it partially, and some include coverage for skilled nursing coinsurance or a limited foreign travel emergency benefit. Medicare.gov publishes a side-by-side chart that shows what each letter includes.

Massachusetts, Minnesota, and Wisconsin standardize their Medigap plans differently, but Louisiana follows the standard federal lettering.

When you can buy a Medigap plan

Timing matters more with Medigap than most people realize. Your best window is the Medigap Open Enrollment Period — a one-time, six-month window that starts the month you're 65 or older and enrolled in Part B. During that window, insurers can't turn you down or charge you more because of your health.

Outside of that window, in most states insurers can use medical underwriting. That means they can ask health questions and, in some cases, decline your application or charge higher premiums.

There are limited "guaranteed issue" rights in certain situations — for example, if you lose other coverage or move out of a plan's service area. If you think one of those might apply to you, it's worth calling 1-800-MEDICARE or your state SHIP before you assume you're stuck.

Medigap vs. Medicare Advantage — a quick reality check

These are two different paths, not two flavors of the same thing.

• Original Medicare + Medigap + Part D: You use any provider that accepts Medicare, and your Medigap plan helps with the leftover costs. Drug coverage is separate.
• Medicare Advantage (Part C): A private plan that bundles Part A, Part B, and usually Part D, often with a network of providers and different cost-sharing rules.

You can't stack Medigap on top of a Medicare Advantage plan. If you want to switch between the two paths, the calendar matters — see the deadlines below.

What Medigap does not help with

Even a comprehensive Medigap letter has limits. It generally will not cover:

• Prescription drugs (you need a Part D plan; the 2026 Part D out-of-pocket cap is $2,100, and the maximum Part D deductible is $615).
• Routine dental, vision, or hearing aids.
• Long-term custodial care.
• Cosmetic procedures.

The Part D coverage gap — the old "donut hole" — was eliminated as of 2025, so drug costs now move through three phases instead of four. That's a Part D change, not a Medigap change, but it often comes up in the same conversation.

Also worth knowing: higher-income enrollees may pay IRMAA surcharges on Part B and Part D. Those begin above $109,000 in income for a single filer in 2026.

Key dates to keep in mind

• October 15 – December 7: Medicare Annual Enrollment Period. This is when you can join, switch, or drop a Medicare Advantage or Part D plan.
• January 1 – March 31: Medicare Advantage Open Enrollment Period. If you're already in a Medicare Advantage plan, you can switch to another one or return to Original Medicare (and potentially add Medigap and Part D, subject to underwriting rules).

Medigap itself doesn't follow the AEP calendar the way Advantage and Part D do — you can apply for a Medigap policy any time of year — but your ability to be accepted often depends on whether you're in a protected enrollment window.

What's available around Houma

Houma is in Terrebonne Parish, where Medicare enrollees generally have access to multiple Medigap carriers as well as Medicare Advantage and Part D plans. Availability and pricing are set at the parish level and can change year to year, so it's worth checking the Medicare Plan Finder at medicare.gov/plan-compare during shopping season.