Medicare Supplement

Medigap, explained: what those Plan letters really cover

Medicare Supplement insurance — often called Medigap — is one of the most misunderstood parts of Medicare. If you live in Charlotte and you're weighing how to fill the gaps in Original Medicare, it helps to know exactly what Medigap does, what it doesn't, and how those standardized "plan letters" work.

What Medigap actually does

Original Medicare pays a large share of your hospital and doctor bills, but not all of it. You're still responsible for things like the Part A hospital deductible, the 20% coinsurance under Part B, and certain other out-of-pocket costs. There is no yearly out-of-pocket limit built into Original Medicare on its own.

A Medigap policy is private insurance you can buy to help cover those leftover costs. You pay a monthly premium to the insurance company, and in return, the policy picks up some or all of the gaps, depending on which lettered plan you choose.

Medigap only works alongside Original Medicare. You cannot use a Medigap policy with a Medicare Advantage plan.

How the standardized letters work

Here's the part that trips people up. In most states, including North Carolina, Medigap plans are sold using standardized letters: A, B, D, G, K, L, M, and N. (Plans C and F are still available, but only to people who were eligible for Medicare before January 1, 2020.)

The benefits inside each letter are set by federal law. That means Plan G from one insurer covers the same core benefits as Plan G from another insurer. What can differ is the price, the customer service, and extras like discounts or wellness perks.

So when you compare Medigap policies, you're really comparing:

• Which letter (which set of benefits) fits your situation.
• Which company offers that letter at a price and with service you're comfortable with.

What Medigap does not cover

Medigap is designed to help with cost-sharing under Original Medicare — not to add new categories of coverage. In general, Medigap does not pay for:

• Prescription drugs (you'd need a separate Part D plan).
• Routine dental, vision, or hearing care.
• Hearing aids or eyeglasses.
• Long-term care, like a stay in a nursing home for custodial reasons.
• Private-duty nursing.

If drug coverage matters to you — and for most people it does — remember that Part D has a $2,100 out-of-pocket cap in 2026, a maximum deductible of $615, and an optional Medicare Prescription Payment Plan that lets you spread drug costs across the year in monthly installments.

Timing matters: the Medigap Open Enrollment Period

This is the piece a lot of Charlotte readers wish they'd known sooner. Your Medigap Open Enrollment Period is a one-time, six-month window that starts the first month you're both 65 or older and enrolled in Part B.

During that window, insurance companies must sell you any Medigap policy they offer at the same price as a healthy person, regardless of your health history. Outside that window, in most cases, insurers in North Carolina can use medical underwriting — meaning they can charge you more or turn you down based on your health.

That's a very different rule from Medicare Advantage and Part D, which have the fall Annual Enrollment Period from October 15 to December 7, and a Medicare Advantage Open Enrollment Period from January 1 to March 31.

Medigap and Medicare Advantage: not the same thing

It's worth saying plainly: Medigap and Medicare Advantage (Part C) are two different paths, and you can only be on one at a time.

• Original Medicare + Medigap + (usually) Part D: You use your red, white, and blue Medicare card, see any provider who accepts Medicare, and your Medigap policy helps with the leftover costs.
• Medicare Advantage: A private plan that replaces how you get your Part A and Part B benefits, usually with a provider network and often with drug coverage bundled in.

Charlotte is in Mecklenburg County, where Medicare beneficiaries have a wide range of Medicare Advantage and Part D plans available each year. But Medigap availability is regulated differently — it's based on what insurers file with the North Carolina Department of Insurance, not on the county-by-county Medicare Advantage landscape.

If your income is above $109,000 as a single filer in 2026, keep in mind that IRMAA surcharges can raise your Part B and Part D premiums, regardless of which path you choose.

How to decide what fits you

There's no single "right" Medigap plan. A few questions can help narrow it down:

• How often do you see doctors or specialists, and how comfortable are you with paying some cost-sharing yourself?
• Do you travel often, or split time outside North Carolina? Some Medigap plans include foreign travel emergency coverage.
• Is a lower monthly premium more important to you, or a more predictable bill when you actually use care?
• Are you inside your six-month Medigap Open Enrollment Period, or will you need to go through underwriting?

A licensed agent, your local SHIP counselor, or the plan finder on medicare.gov can walk through the specific letters side by side with you.