Medicare Supplement

Medigap in Gladstone: how those A-through-N letters work

GLADSTONE, Mo. — If you have Original Medicare and the alphabet soup of "Plan A," "Plan G," and "Plan N" is making your head spin, you're not alone. Medicare Supplement insurance — better known as Medigap — is one of the most misunderstood pieces of the Medicare puzzle. Here's a plain-language look at what it actually does, and why every Medigap policy sold today comes with a letter attached.

Medicare Supplement insurance, explained: what Medigap does and doesn't cover

What Medigap actually does

Original Medicare (Part A and Part B) pays for most of your hospital and doctor care, but not all of it. You're still on the hook for things like the Part A hospital deductible, the 20% coinsurance under Part B, and — importantly — there is no yearly out-of-pocket limit on Original Medicare by itself.

A Medigap policy is sold by a private insurance company and steps in to help cover those leftover costs. Depending on the letter plan you choose, it may pay some or all of your deductibles, coinsurance, and copayments. You keep your Original Medicare, and Medigap works alongside it as secondary coverage.

Why the letters matter

Here's the part that trips people up: Medigap plans are standardized by the federal government. That means a Plan G sold by Company A has to cover the exact same core benefits as a Plan G sold by Company B. The letter tells you what's covered — the company sets the price and the customer service.

The plans currently available to new enrollees are lettered A, B, D, G, K, L, M, and N. (Plans C and F are no longer sold to people who became eligible for Medicare on or after January 1, 2020, because those plans covered the Part B deductible.) High-deductible versions of Plan G and Plan F also exist.

Because benefits are standardized, comparison shopping mostly comes down to price, the company's reputation, and how premiums may change over time.

What Medigap does not cover

Medigap is not a catch-all. It generally does not cover:

• Prescription drugs. You'll need a stand-alone Part D plan for that. In 2026, Part D has a maximum deductible of $615 and a new $2,100 annual out-of-pocket cap, and the old coverage gap ("donut hole") has been eliminated as of 2025.
• Long-term care, such as extended stays in a nursing home.
• Routine dental, vision, or hearing care, including dentures and hearing aids.
• Private-duty nursing.

If those benefits matter to you, you'd need separate coverage, or you'd need to compare Original Medicare + Medigap against a Medicare Advantage plan, which bundles things differently. You cannot have both Medigap and a Medicare Advantage plan at the same time.

Medigap vs. Medicare Advantage — a quick note

Gladstone is in Clay County, where residents have both paths available: staying with Original Medicare (often paired with Medigap and a Part D plan) or enrolling in a Medicare Advantage plan that combines coverage under one policy. Medigap is only for people who stay with Original Medicare. This is a personal decision based on your doctors, your prescriptions, your budget, and how you feel about networks — not a one-size-fits-all answer.

When to buy — the timing that protects you

The single most important thing to know about Medigap is your Medigap Open Enrollment Period. It's a one-time, six-month window that starts the month you're 65 or older and enrolled in Part B. During this period, insurance companies can't turn you down or charge you more because of your health.

Miss that window, and in most states — including Missouri — insurers can use medical underwriting to decide whether to sell you a policy and at what price. There are limited "guaranteed issue" situations later on, but the smoothest time to enroll is that first six-month window.

Note that this is different from the fall Annual Enrollment Period (October 15 – December 7), which is for Part D and Medicare Advantage — not Medigap.