Medicare Supplement

How Medigap letter plans work for Ithaca Medicare users

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

ITHACA, N.Y. — If you have Original Medicare and you've ever looked at a hospital bill, you already know Medicare doesn't pay for everything. There are deductibles, coinsurance, and copays that can add up. That's the gap Medicare Supplement insurance — often called Medigap — is designed to help fill.

Medigap is not the same as Medicare Advantage, and it's not a drug plan. It's a separate private policy that works alongside Original Medicare (Part A and Part B). What confuses many people is the alphabet: Plan A, Plan B, Plan D, Plan G, Plan K, Plan L, Plan M, Plan N. Here's a plain-English guide to how those letters work and what to check before you pick one.

What Medigap actually does

Original Medicare pays most of your hospital and doctor costs, but you're still responsible for things like the Part A hospital deductible, Part B coinsurance (usually 20% of the Medicare-approved amount), and certain other charges. A Medigap policy picks up some or all of those out-of-pocket costs, depending on which lettered plan you choose.

Medigap does not cover:

• Prescription drugs (you'd need a separate Part D plan)
• Routine dental, vision, or hearing care
• Long-term care
• Private-duty nursing

If you want drug coverage, you buy a stand-alone Part D plan separately.

How the standardized letters work

Medigap plans are standardized by the federal government. That means a Plan G sold by one insurance company covers the same core benefits as a Plan G sold by another company — the price and customer service can differ, but the benefits are set by law. (Massachusetts, Minnesota, and Wisconsin standardize plans a little differently.)

In most states, including New York, you'll see these letters offered: A, B, D, G, K, L, M, and N. Plans C and F are still available, but only to people who became eligible for Medicare before January 1, 2020.

Each letter represents a set package of benefits. Some plans cover nearly all of your Medicare cost-sharing; others cover less and cost less. A few plans (K and L) include an annual out-of-pocket limit. Because the benefits are standardized, you can compare plans from different insurers letter-by-letter — the main variables become price, the company's reputation, and how they handle rate increases over time.

You can see the full benefits chart on medicare.gov under "Compare Medigap plan benefits."

When to buy — and why timing matters

The most important date in Medigap shopping is the start of your Medigap Open Enrollment Period. This is a one-time, six-month window that begins the month you're both 65 or older and enrolled in Part B.

During that window, insurance companies can't turn you down or charge you more because of your health. Miss it, and in many states insurers can use medical underwriting — meaning your health history can affect whether you're accepted and what you'll pay.

New York has some of the country's more consumer-friendly Medigap rules, but the six-month window is still the cleanest time to enroll. If you're unsure how the rules apply to you, call your local State Health Insurance Assistance Program (SHIP) before you decide.

How Medigap fits with Ithaca-area coverage

Ithaca is in Tompkins County, where residents can choose between Original Medicare (often paired with a Medigap policy and a stand-alone Part D plan) or a Medicare Advantage plan that bundles coverage together. You can't have both a Medigap policy and a Medicare Advantage plan at the same time — you pick one path.

Medicare Advantage availability is set at the county level and changes each year. Medigap availability, on the other hand, is regulated by New York State, so the lettered plans on offer look similar across the state, though prices vary by insurer and ZIP code.

What to check before you enroll

A few practical things to look at:

• Which letter matches your needs. More coverage generally means a higher premium. A plan with lower premiums but more cost-sharing may still make sense if you don't expect heavy medical use.
• How the insurer prices the plan. Medigap premiums can be set by community rating, issue-age rating, or attained-age rating. Ask how future increases work.
• Whether you also need Part D. Medigap doesn't include drugs. In 2026, Part D has a maximum deductible of $615 and a new $2,100 annual out-of-pocket cap on covered drugs.
• Your enrollment windows. The Medicare Annual Enrollment Period (Oct. 15 – Dec. 7) and the Medicare Advantage Open Enrollment Period (Jan. 1 – March 31) apply to Part D and Medicare Advantage — not to Medigap, which has its own timing rules.