Medicare Supplement

Why Medicare Supplement uses letters: a Danbury guide

DANBURY, Conn. — If you've been shopping for a way to fill the gaps in Original Medicare, you've probably run into a wall of letters: Plan A, Plan G, Plan N, and more. That alphabet is Medicare Supplement Insurance, better known as Medigap — and once you understand how it's built, the choices get a lot less confusing.

Medigap is a private insurance policy that works alongside Original Medicare (Part A and Part B). It helps pay some of the costs Medicare doesn't cover, like coinsurance and copayments. It does not replace Medicare, and it is not the same thing as a Medicare Advantage plan.

What Medigap actually does

Original Medicare pays a big share of your hospital and doctor bills, but it leaves you responsible for deductibles, coinsurance (often 20% of the Part B-approved amount), and some copayments. There is no annual out-of-pocket limit built into Original Medicare.

A Medigap policy steps in to help pay some or all of those remaining costs. Depending on the letter you choose, it may cover the Part A hospital deductible, Part B coinsurance, the first three pints of blood, hospice coinsurance, skilled nursing facility coinsurance, and even a portion of foreign travel emergency care.

What Medigap does not do: it doesn't cover prescription drugs, dental, vision, hearing aids, long-term care, or private-duty nursing. Those need separate coverage.

How the standardized letters work

Here's the part that trips people up. In most states, including Connecticut, Medigap plans are standardized by the federal government. That means the benefits inside "Plan G" are identical no matter which insurance company sells it. A carrier can't add or subtract benefits from a lettered plan.

What can differ between companies:

• The monthly premium
• How the company sets rates (by age, or the same for everyone)
• Customer service and billing
• Whether the plan is offered at all in your area

Currently, the lettered plans available to new enrollees include A, B, D, G, K, L, M, and N. Plans C and F are only available to people who were eligible for Medicare before January 1, 2020, because those plans covered the Part B deductible, which newer enrollees can no longer buy through Medigap.

There's also a high-deductible version of Plan G and Plan F for people who prefer a lower premium in exchange for paying more up front.

Medigap vs. Medicare Advantage — they're not the same

This is one of the most common mix-ups. Medigap is a supplement to Original Medicare. Medicare Advantage (Part C) is a different way to get your Medicare benefits, offered through private plans that bundle Part A, Part B, and usually Part D.

You cannot have both a Medigap policy and a Medicare Advantage plan at the same time. It's one path or the other. Danbury is in Fairfield County, where residents can shop among Medicare Advantage plans and stand-alone Part D plans during Medicare's regular enrollment windows — but Medigap has its own separate enrollment rules, explained below.

Timing matters — a lot

Your best window to buy a Medigap policy is the six-month Medigap Open Enrollment Period that begins the first month you're 65 or older and enrolled in Part B. During that window, insurance companies must sell you any Medigap policy they offer at their best available rate, and they can't turn you down or charge you more because of pre-existing conditions.

Miss that window and, in most cases, insurers can use medical underwriting — meaning they can review your health history and potentially deny coverage or charge more. Some states have extra protections; Connecticut has stronger consumer rules than many states, so it's worth checking with the Connecticut Insurance Department or your local SHIP counselor about your specific rights.

The federal Annual Enrollment Period (Oct. 15 – Dec. 7) and Medicare Advantage Open Enrollment (Jan. 1 – March 31) apply to Advantage and Part D plans — not Medigap. Medigap can generally be applied for at any time of year, but without guaranteed-issue rights outside of your specific windows.

Don't forget drug coverage

Medigap doesn't include prescriptions. If you go with Original Medicare + Medigap, you'll almost always want to add a stand-alone Part D drug plan.

For 2026, a few program-level facts to keep in mind:

• The Part D out-of-pocket cap is $2,100.
• The maximum Part D deductible is $615.
• The old "donut hole" coverage gap is gone as of 2025 — Part D now has three phases.
• The Medicare Prescription Payment Plan lets you spread your drug costs across the year in monthly installments instead of paying large amounts at the pharmacy counter.
• Higher-income enrollees may pay IRMAA surcharges on Part B and Part D; for a single filer in 2026, IRMAA starts above $109,000 in income.

Common mistakes to avoid

• Assuming all "Plan G" policies are different. The benefits are the same by law — compare price and company service, not the benefit chart.
• Waiting too long. Missing your six-month Medigap Open Enrollment window can make it harder or more expensive to get covered later.
• Trying to stack Medigap on a Medicare Advantage plan. It's not allowed, and it's illegal for anyone to sell you a Medigap policy while you're on Advantage unless you're switching back to Original Medicare.
• Forgetting drug coverage. Medigap won't help with medications — you'll need Part D or you could face a late-enrollment penalty later.