Medicare Supplement

Medicare Supplement basics for Rockford: letters explained

ROCKFORD, Ill. — If you've ever looked at a Medicare bill and wondered why you owe so much after Medicare "paid," you're not alone. That gap between what Original Medicare covers and what you owe is exactly what Medicare Supplement insurance — often called Medigap — is designed to help with.

Here's a plain-language guide to how Medigap works, what those standardized letters mean, and the mistakes that trip people up.

What Medigap Is (and What It Isn't)

Medigap is private insurance you can buy to help pay some of the out-of-pocket costs that Original Medicare (Part A and Part B) leaves behind. Think coinsurance, copays, and hospital deductibles.

A few things Medigap is not:

• It is not part of Medicare Advantage. In fact, you cannot have both at the same time.
• It is not drug coverage. For prescriptions, you'll still need a separate Part D plan.
• It usually does not cover dental, vision, hearing aids, or long-term care.

Medigap works alongside Original Medicare. Medicare pays its share first, then your Medigap policy picks up its share of what's left.

How the Standardized Letters Work

This is where a lot of confusion happens. In most states, including Illinois, Medigap policies are standardized by the federal government and labeled with letters: A, B, C, D, F, G, K, L, M, and N.

Here's the key idea: a Plan G from one company covers the exact same core benefits as a Plan G from another company. The letters tell you the benefit package. What differs between companies is the price, customer service, and extras.

A few notes worth knowing:

• Plans C and F are only available to people who became eligible for Medicare before January 1, 2020. If you turned 65 in 2020 or later, those two are off the table.
• Plans K and L have lower premiums but higher out-of-pocket limits.
• Plan N typically has small copays for some office and ER visits.

Because the benefits inside each letter are set by law, comparing Medigap really does come down to price and the company behind the policy.

The Enrollment Window That Matters Most

Here is the mistake we see over and over: waiting too long to buy Medigap.

You get a one-time, six-month Medigap Open Enrollment Period that starts the month you're 65 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.

Miss that window, and in most cases companies can use medical underwriting. That means they can charge you more, or turn you down, based on your health. A few states offer extra protections, but Illinois generally follows the federal rules.

If you're approaching 65 in Rockford, mark that six-month window on your calendar. It's one of the most valuable timing rules in all of Medicare.

Medigap vs. Medicare Advantage: A Quick Reality Check

People sometimes assume Medigap and Medicare Advantage are two flavors of the same thing. They're not.

• Medigap works with Original Medicare. You can see any doctor in the country who accepts Medicare. You add a separate Part D plan for drugs.
• Medicare Advantage replaces Original Medicare with a private plan that bundles hospital, medical, and usually drug coverage — often with a network of doctors.

Rockford is in Winnebago County, where residents have both Medicare Advantage plans and Medigap policies to choose from. Neither approach is "better" for everyone — they're just structured differently.

Where Drug Costs Fit In

Medigap does not cover prescriptions, so most people pair it with a stand-alone Part D plan. A few 2026 numbers to keep in mind, straight from Medicare:

• The Part D out-of-pocket cap is $2,100 in 2026. Once you hit it, you pay $0 for covered drugs the rest of the year.
• The maximum Part D deductible is $615.
• The old "donut hole" coverage gap was eliminated in 2025, so Part D now has three phases instead of four.
• The Medicare Prescription Payment Plan lets you spread your drug costs out over the year in monthly payments instead of paying all at once at the pharmacy.

Higher earners may also pay IRMAA surcharges on Part B and Part D — those begin above $109,000 in income for a single filer in 2026.

Common Mistakes to Avoid

• Assuming all "Plan G" policies are different. The benefits are identical by law; compare prices and the company's track record.
• Waiting past your six-month Open Enrollment window. Health underwriting can lock you out later.
• Forgetting Part D. Medigap has no drug coverage. You need a separate plan or creditable coverage from elsewhere.
• Trying to have both Medigap and Medicare Advantage. It's not allowed, and it's illegal for anyone to sell you both.