Medicare Supplement

Medigap Plan Letters Explained for Greeley Medicare Users

Medigap Plan Letters Explained for Greeley Medicare Users — plain-language Medicare information for Greeley, Colorado.

GREELEY, Colo. — If you've started shopping for a Medicare Supplement policy, you've probably noticed something curious: the plans are labeled with letters like A, G, and N. That's not a marketing gimmick. It's a federal standardization system, and once you understand how it works, comparing Medigap coverage in northern Colorado gets a lot easier.

What Medigap actually does

Medicare Supplement Insurance — usually called Medigap — is a private policy that works alongside Original Medicare (Parts A and B). Original Medicare pays most of your hospital and doctor bills, but it leaves you responsible for deductibles, coinsurance, and copayments. Those leftover costs can add up, especially if you have a long hospital stay or need ongoing care.

A Medigap policy steps in to help cover some or all of those gaps. You pay a monthly premium to the insurance company, and in return the policy picks up a share of what Original Medicare doesn't. According to Medicare.gov, you must be enrolled in both Part A and Part B to buy a Medigap plan.

Why the plans have letters

Here's the part that trips people up. In most states, including Colorado, Medigap plans are standardized by the federal government. That means every Plan G sold in Greeley covers the exact same benefits as every other Plan G — no matter which insurance company is selling it.

The letters currently offered to new enrollees include A, B, D, G, K, L, M, and N. (Plans C and F are only available to people who became eligible for Medicare before January 1, 2020.) Each letter represents a different mix of benefits. Plan A covers the basics. Plans G and N are among the more comprehensive options. Plans K and L have cost-sharing built in, with lower premiums in exchange.

Because the benefits are fixed, when you compare two Plan G policies from two different carriers, the only real differences are the monthly premium, the company's customer service, and how they handle rate increases over time.

Medigap in Weld County

Greeley sits in Weld County, where Medigap options are regulated at both the federal and state level. Colorado follows the standard federal lettering system, so the plan structures you'll see here match what's sold across most of the country. The insurance companies that offer Medigap in Weld County can vary, and premiums for the same lettered plan can differ from one carrier to the next, which is why side-by-side comparison matters.

You can look up which carriers sell Medigap in your ZIP code using the plan finder at medicare.gov.

Medigap is not Medicare Advantage

This is one of the most common points of confusion. Medigap and Medicare Advantage (Part C) are two different paths, and you can only be on one at a time.

• Medigap works with Original Medicare and helps pay the out-of-pocket costs Original Medicare leaves behind. It doesn't include prescription drug coverage.
• Medicare Advantage replaces Original Medicare with a private plan that bundles Parts A, B, and usually D together.

If you have Medigap, you'll typically also want a stand-alone Part D drug plan. In 2026, Part D has a maximum deductible of $615 and, for the first time at this level, a $2,100 annual cap on what you pay out of pocket for covered drugs. The old coverage gap — the "donut hole" — was eliminated in 2025.

When to buy: the enrollment window that matters

Timing is everything with Medigap. Your Medigap Open Enrollment Period is a one-time, six-month window that starts the month you turn 65 and are enrolled in Part B. During that window, insurance companies must sell you any Medigap policy they offer at their best available rate, regardless of your health history.

After that window closes, in most cases carriers can use medical underwriting — meaning they can charge you more or turn you down based on your health. That's why many people who want a Medigap plan make the decision during that first six months.

The Medicare Annual Enrollment Period (October 15 to December 7) and the Medicare Advantage Open Enrollment Period (January 1 to March 31) apply to Medicare Advantage and Part D — not Medigap. Medigap has its own rules.