Medicare Supplement

Medigap, Explained: What Those Letter Plans Actually Cover

LARAMIE, Wyo. — If you've started reading about Medicare, you've probably run into a wall of letters: Plan A, Plan G, Plan N, and more. Those letters refer to Medicare Supplement Insurance, better known as Medigap. It's one of the more confusing corners of Medicare, but the good news is that once you understand the structure, the choices get a lot easier to compare.

Here's a plain-language walk-through of what Medigap does, what it doesn't do, and how those standardized letters work.

What Medigap actually is

Medigap is private insurance that works alongside Original Medicare (Part A and Part B). It doesn't replace Medicare — it fills in some of the out-of-pocket costs Original Medicare leaves behind, like coinsurance, copayments, and certain deductibles.

You pay a monthly premium to a private insurance company for a Medigap policy, and you keep paying your Part B premium to Medicare. When you get care, Medicare pays its share first, then your Medigap policy pays its share of what's left, based on the letter plan you chose.

Medigap only works with Original Medicare. If you're enrolled in a Medicare Advantage plan (Part C), you generally can't use a Medigap policy — the two aren't designed to work together.

How the standardized letters work

This is the part that trips people up. Medigap plans are labeled with letters — A, B, C, D, F, G, K, L, M, and N. In most states, including Wyoming, these plans are standardized by the federal government. That means Plan G from one insurance company covers the exact same things as Plan G from another company. The benefits are set by law.

What can differ between companies:

• The monthly premium
• Customer service
• How the company handles rate increases over time

So if you're comparing two Plan G policies, you're really comparing price and the company behind the policy — not the benefits themselves.

A quick note on Plans C and F: These plans cover the Part B deductible, but they're only available to people who became eligible for Medicare before January 1, 2020. If you became eligible on or after that date, Plans C and F aren't options for you. Plan G is often discussed as the closest alternative for newer enrollees, according to Medicare.gov.

What Medigap does not cover

This is where readers get surprised, so it's worth spelling out. Standard Medigap policies generally do not cover:

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

If you want prescription drug coverage alongside Original Medicare and a Medigap policy, you enroll in a stand-alone Part D plan separately.

Why timing matters more than most people realize

The single most important thing to know about Medigap is your Medigap Open Enrollment Period. This is a six-month window that starts the month you're 65 or older and enrolled in Part B. During this window, insurance companies must sell you any Medigap policy they offer at their best available rate, regardless of your health history.

Outside that window, in most states, insurers can use medical underwriting — meaning they can charge you more or turn you down based on your health. Wyoming follows federal rules here, so if you miss your open enrollment window, buying Medigap later can get harder and more expensive.

Laramie is in Albany County, and Medigap availability isn't tied to your county the way Medicare Advantage plans are. Medigap policies are sold statewide by licensed insurers, so your options are shaped by Wyoming's insurance market, not your ZIP code.

How Medigap fits with 2026 Medicare changes

A few program-level updates worth keeping in mind as you weigh your choices:

• Part D out-of-pocket cap: In 2026, your prescription drug spending under Part D is capped at $2,100 for the year.
• Part D deductible: The maximum allowed deductible is $615.
• Coverage gap gone: The old "donut hole" has been eliminated as of 2025 — Part D now has three phases instead of four.
• Medicare Prescription Payment Plan: You can choose to spread your drug costs across monthly payments instead of paying all at once at the pharmacy.
• IRMAA: Higher-income enrollees pay surcharges on Part B and Part D. In 2026, those surcharges start above $109,000 in income for a single filer.

None of these changes alter what Medigap itself covers, but they do change the math on Part D, which most Medigap enrollees pair with their coverage.