Medicare Supplement

Understanding Medigap: What Those Plan Letters Really Mean

LEBANON, N.H. — If you've ever tried to shop for a Medicare Supplement policy, you've probably run into a wall of letters: Plan A, Plan G, Plan N, Plan K. It can feel like alphabet soup. But once you understand how these letters work, Medigap becomes one of the easier pieces of Medicare to sort out.

Here's a plain-language guide to what Medigap does, how the standardized letters work, and where Lebanon-area readers can turn for one-on-one help.

What Medigap actually does

Medicare Supplement Insurance — usually called Medigap — is private insurance that works alongside Original Medicare (Part A and Part B). It doesn't replace Medicare. Instead, it helps pay some of the out-of-pocket costs Original Medicare leaves behind, such as coinsurance, copayments, and in some cases the Part A hospital deductible.

Medigap is different from a Medicare Advantage plan (Part C). You can have one or the other, not both. Medigap also doesn't include prescription drug coverage — for that, most people add a separate Part D plan.

Why the plans are labeled with letters

Here's the part that trips people up. In most states, Medigap policies are standardized by the federal government. That means a Plan G sold by one company covers the exact same set of benefits as a Plan G sold by another company. The letter tells you what's covered.

What can differ between companies:

• The monthly premium
• Customer service and how the company handles claims
• Whether household or other discounts are offered
• How the company prices policies as you age

So if you're comparing two Plan Gs, you're comparing price and company — not benefits.

The letters currently sold

According to Medicare.gov, the Medigap plans available to new enrollees are A, B, D, G, K, L, M, and N. Plans C and F are still around, but only people who became eligible for Medicare before January 1, 2020, can buy them.

Two of the letters — K and L — work a little differently. They have lower premiums but ask you to share more of the cost up front, with a yearly out-of-pocket limit. Plan G is currently the most comprehensive option for newly eligible enrollees.

Massachusetts, Minnesota, and Wisconsin standardize their Medigap plans differently, so residents there see a different menu. New Hampshire uses the standard federal lettering.

When you can buy Medigap matters

The best time to buy a Medigap policy is during your six-month Medigap Open Enrollment Period, which starts the month you're 65 or older and enrolled in Part B. During this window, insurance companies can't turn you down or charge you more because of your health.

Outside that window, in most states, companies can use medical underwriting — meaning your health history could affect whether you can get a policy and what you'll pay. That's why timing is such an important part of the Medigap conversation.

How Medigap fits with the rest of Medicare in 2026

Medigap only helps with costs under Original Medicare Parts A and B. It does not cap your prescription drug costs. That's the job of Part D, which in 2026 has a $2,100 annual out-of-pocket cap and a maximum deductible of $615, according to Medicare.gov. The old coverage gap ("donut hole") was eliminated in 2025, and the Medicare Prescription Payment Plan lets you spread drug costs across the year in monthly installments if that helps your budget.

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

What's available around Lebanon

Lebanon is in Grafton County, where Medicare enrollees can choose Original Medicare with or without a Medigap policy, or a Medicare Advantage plan. Plan availability and the number of companies offering Medigap are set at the state and county level, not the city level. To see current options in Grafton County, use the plan finder at Medicare.gov or call 1-800-MEDICARE.