Medicare Supplement

Why Medigap plan letters mean the same in Richardson

RICHARDSON, Texas — If you are shopping for a Medicare Supplement policy, you have probably noticed the letters. Plan A, Plan G, Plan N, and several in between. Those letters are not random branding. They are a federal shorthand that tells you exactly what a Medigap policy covers, no matter which insurance company sells it.

Here is what those standardized letters mean, why they matter, and how to use them when you compare options in Richardson.

What Medigap actually does

Medicare Supplement Insurance, or Medigap, is a private policy that helps pay some of the out-of-pocket costs Original Medicare leaves behind — things like the Part A hospital deductible, coinsurance, and copayments. It does not replace Medicare. It rides alongside it.

When you have a Medigap policy, Medicare pays its share of an approved claim first. Then your Medigap policy pays its share. You still pay your monthly Part B premium, plus the Medigap premium to your insurance company.

Medigap is different from Medicare Advantage (Part C). You cannot have both at the same time. Medigap only works with Original Medicare.

Why the letters exist

Before the plans were standardized, comparing supplement policies was confusing. Every insurer sold something different. Congress fixed that. Today, in most states including Texas, Medigap policies are sold as lettered plans: A, B, C, D, F, G, K, L, M, and N. (Plans C and F are only available to people who became eligible for Medicare before Jan. 1, 2020.)

Here is the important part: the benefits in each lettered plan are set by federal rules. Plan G sold by one company covers the same gaps as Plan G sold by another. The company can set its own premium, its own customer service, and its own extras — but the core benefits inside that letter do not change.

That means you can compare Medigap plans mostly on price and the company behind them, not on a maze of different benefit charts.

What each letter tends to cover

Each lettered plan covers a different mix of Medicare cost-sharing. Some cover almost everything Original Medicare leaves behind. Others cover less and come with lower premiums. A few, like Plans K and L, use a percentage cost-sharing structure with an annual out-of-pocket limit.

Because this is educational content, we will not steer you to a specific letter. What matters is that once you know which letter you want, you can shop that letter across carriers.

You can see the full benefit chart for every lettered plan at Medicare.gov.

The Richardson angle

Richardson is in Dallas County, where seniors have a wide range of both Medicare Advantage plans and Medigap carriers to choose from. Availability of Medigap policies is regulated at the state level in Texas, but the lettered benefits are set by federal law — so a Plan N marketed to a Richardson resident carries the same core benefits as a Plan N marketed anywhere else in the country.

Premiums, though, can vary a lot between companies for the exact same letter. That is why comparing quotes matters.

When to buy — the deadline that matters most

The single most important date for Medigap is your Medigap Open Enrollment Period. It lasts six months and starts the first month you are both 65 or older and enrolled in Medicare Part B.

During that window, you have a guaranteed right to buy any Medigap policy sold in Texas, at the best available rate, regardless of your health history. After it closes, insurers in most cases can use medical underwriting — meaning they can charge you more, or turn you down, based on your health.

Certain "guaranteed issue" situations (like losing other coverage) can reopen a limited right to buy. But nothing is as broad as that first six-month window.

Note: The Annual Enrollment Period (Oct. 15 – Dec. 7) and the Medicare Advantage Open Enrollment Period (Jan. 1 – March 31) apply to Medicare Advantage and Part D — not to Medigap.

Don't forget drug coverage

Medigap does not include prescription drug coverage. If you go with Original Medicare plus a Medigap policy, you will typically also want to enroll in a stand-alone Part D plan.

For 2026, Part D has a maximum deductible of $615 and a new $2,100 annual out-of-pocket cap on covered drugs. The old coverage gap ("donut hole") was eliminated in 2025, so Part D now runs in three phases. Medicare also offers an optional Prescription Payment Plan that lets you spread drug costs across the year in monthly payments.