Medicare Supplement

The reason Medigap plans use letters, explained for Cleveland

CLEVELAND, Ohio — If you have ever tried to make sense of Medicare Supplement Insurance — better known as Medigap — you have probably run into a wall of letters: Plan A, Plan G, Plan N, and more. It can feel like alphabet soup. But there is a good reason for those letters, and understanding them is one of the most useful things a Medicare shopper can do.

Medigap is private insurance that works alongside Original Medicare (Part A and Part B) to help pay some of the out-of-pocket costs Medicare leaves behind, such as coinsurance and copayments. To make comparison easier, the federal government standardized these plans by letter. That means a Plan G sold by one insurance company covers the same things as a Plan G sold by another company.

What Medigap actually does

Original Medicare pays a large share of your hospital and doctor bills, but not all of it. You are still on the hook for things like the Part A hospital deductible, Part B coinsurance (usually 20% of the approved amount), and other gaps.

A Medigap policy steps in to cover some or all of those leftover costs, depending on which lettered plan you choose. You pay a monthly premium to the insurance company for that extra coverage, on top of your Part B premium.

Medigap does not include prescription drug coverage. If you want help paying for medications, you would add a separate Part D plan.

Why the letters exist

Before standardization, Medigap plans varied wildly, and shoppers had a hard time comparing them. Today, in most states, Medigap plans come in 10 standardized versions labeled A, B, C, D, F, G, K, L, M, and N. (Massachusetts, Minnesota, and Wisconsin use their own systems.)

Here is the key point: the letter tells you the benefits. Plan G from Company X covers the same gaps as Plan G from Company Y. What can differ is the premium, the customer service, and how the company handles rate increases over time. So when you compare Medigap plans, you are really comparing companies within the same letter.

Two notes worth knowing:

• Plans C and F are no longer sold to people who became eligible for Medicare on or after January 1, 2020. If you were eligible before that date, you may still be able to buy them.
• Plans K and L have out-of-pocket limits, while most other letters do not.

How Medigap differs from Medicare Advantage

This is where many people get tripped up. Medigap and Medicare Advantage (Part C) are two different roads — you cannot travel both at once.

• Medigap adds to Original Medicare. You keep Parts A and B, and Medigap fills gaps.
• Medicare Advantage replaces the way you get your Original Medicare benefits. It bundles Part A, Part B, and usually Part D through a private plan.

Cleveland is in Cuyahoga County, where residents have a wide range of Medicare Advantage plans and Part D drug plans available. But Medigap is separate from those choices, and if you are enrolled in a Medicare Advantage plan, it is generally illegal for someone to sell you a Medigap policy.

When to buy Medigap

Timing matters more than most people realize. Your Medigap Open Enrollment Period is a one-time, six-month window that starts the month you are 65 or older and enrolled in Part B. During this window, you have a "guaranteed issue" right: insurers must sell you any Medigap plan they offer at their best available rate, regardless of your health history.

Outside that window, in most states, insurers can use medical underwriting. That means they can look at your health, charge you more, or decline to sell you a policy. There are a few special "guaranteed issue" situations later on — for example, if a plan you had is discontinued — but the safest time to shop is that first six-month window.

The 2026 numbers to keep in mind

Even though Medigap itself has its own premiums (set by each insurer), a few program-level facts for 2026 shape the bigger picture:

• Part D out-of-pocket cap: $2,100 for the year. Once you hit that on covered drugs, you pay $0 for the rest of the calendar year.
• Part D maximum deductible: $615.
• The coverage gap ("donut hole") was eliminated in 2025. Part D now has three phases instead of four.
• Medicare Prescription Payment Plan: an optional program that lets you spread your drug costs over monthly payments instead of paying at the pharmacy counter.
• IRMAA surcharges begin above $109,000 in income for a single filer in 2026, which can raise your Part B and Part D premiums.
• Annual Enrollment Period: October 15 – December 7 (for Part D and Medicare Advantage changes).
• Medicare Advantage Open Enrollment Period: January 1 – March 31.

Medigap does not follow the October–December enrollment calendar. You can apply for Medigap at any time of year, but outside your six-month window, approval is not guaranteed.

How to compare Medigap plans in Cleveland

Once you decide which lettered plan matches your comfort level with out-of-pocket costs, the next step is comparing what different insurance companies charge for that same letter. Two shoppers looking at Plan G, for example, might see very different premiums from different carriers.

A few practical steps: 1. Use the plan finder tool at medicare.gov to see Medigap policies available in your ZIP code. 2. Ask insurers how they set premiums — by "attained age," "issue age," or "community-rated." This affects how your premium changes as you get older. 3. Consider calling OSHIIP, Ohio's State Health Insurance Assistance Program. Counseling is free and unbiased.