Medicare Supplement

Medigap, explained: what those letter plans actually cover

MESQUITE, Nev. — If you've priced Medicare coverage lately, you've probably run into a wall of letters: Plan A, Plan G, Plan N, Plan K. That's Medicare Supplement Insurance, better known as Medigap. It's private coverage that works alongside Original Medicare to pick up costs Medicare doesn't pay on its own.

Mesquite retirees, here's how Medicare Supplement really works

Medigap isn't a plan that replaces Medicare. It's a helper policy. And once you understand the basics, the alphabet soup gets a lot easier to read.

What Medigap actually does

Original Medicare (Part A and Part B) covers a lot, but it leaves gaps. There's a Part A hospital deductible, a Part B deductible, and coinsurance — usually 20% of the Medicare-approved amount for doctor visits, outpatient care, and many procedures. There's also no yearly cap on what you can spend out of pocket under Original Medicare alone.

A Medigap policy helps fill some or all of those gaps. Depending on the letter you pick, it can pay your Part A hospital coinsurance, some or all of your Part B coinsurance, the Part A deductible, skilled nursing coinsurance, and even limited foreign travel emergency care.

Here's the key thing to know: Medigap works only with Original Medicare. You can't pair it with a Medicare Advantage plan. It's an either/or choice.

Why the plans are labeled with letters

Medigap plans are standardized by the federal government. That means Plan G from one insurance company covers the exact same core benefits as Plan G from another. The price and customer service may differ, but the benefits inside each lettered plan are the same by law.

Today's available letters for people new to Medicare are A, B, D, G, K, L, M, and N. (Plans C and F are still held by people who became eligible for Medicare before Jan. 1, 2020, but new enrollees can't buy them.)

Each letter offers a different mix of coverage:

• Plan A covers the basic benefits — the minimum every Medigap plan must include.
• Plan G is one of the more comprehensive options still open to new enrollees. It covers most gaps except the Part B deductible.
• Plans K and L have lower premiums but ask you to share more of the cost, and they include a yearly out-of-pocket limit.
• Plan N covers most Part B coinsurance but may leave small copays for some office and ER visits.

Because benefits are standardized, shopping Medigap is mostly about comparing price, the insurer's reputation, and how they handle future rate increases.

The best time to buy — and why timing matters so much

There's one window where federal law gives you the strongest rights to buy any Medigap policy sold in your state, at the best available rate, without medical underwriting: your Medigap Open Enrollment Period. It's a 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. Miss it, and in most states, they can — with a few exceptions called "guaranteed issue rights."

This is one of the most important deadlines in all of Medicare, and it's easy to miss because it isn't tied to the fall Annual Enrollment Period you hear about on TV.

How Medigap fits alongside Mesquite's local coverage picture

Mesquite is in Clark County, where Medicare beneficiaries can choose between staying on Original Medicare (often paired with a Medigap policy and a stand-alone Part D drug plan) or enrolling in a Medicare Advantage plan that bundles everything together. Both paths are valid — they just work differently.

If you go the Medigap route, remember you'll also need a separate Part D prescription drug plan. In 2026, Part D has a $2,100 annual out-of-pocket cap on covered drugs, a maximum deductible of $615, and the old coverage gap ("donut hole") has been eliminated — replaced by a simpler three-phase design. There's also an optional Medicare Prescription Payment Plan that lets you spread drug costs across the year in monthly installments.

What Medigap does not cover

Medigap policies generally do not cover:

• Prescription drugs (that's Part D's job)
• Routine dental, vision, or hearing care
• Long-term custodial care in a nursing home
• Hearing aids or eyeglasses

If those benefits matter to you, you'd either add stand-alone coverage or weigh whether a Medicare Advantage plan — which often bundles extras — fits your situation better.

How to decide if Medigap is right for you

A few honest questions can help:

1. How much certainty do you want in your yearly medical costs? Medigap trades a predictable monthly premium for fewer surprise bills. 2. Do you travel or split time between states? Because Medigap follows Original Medicare, you can see any provider nationwide who accepts Medicare — no networks. 3. Are you inside your six-month Medigap Open Enrollment window? If yes, your options are widest right now. 4. Do you take medications regularly? Remember you'll need a separate Part D plan alongside Medigap.

Also worth knowing: if your income is above $109,000 as a single filer in 2026, you may pay an IRMAA surcharge on your Part B and Part D premiums, regardless of which coverage path you pick.