Medicare Supplement

Same Medigap Coverage, Rising Price? Here's Why

In Belleville, shoppers comparing Medicare Supplement (Medigap) policies often notice something puzzling: two people can buy the exact same lettered plan — say, Plan G — from two different insurers and pay very different prices. And a few years later, one of them may see the premium climb while the coverage on paper hasn't changed at all.

That's not a mistake. It's a reflection of how Medigap policies are priced. Federal rules standardize Medigap benefits, but insurers set premiums using one of three pricing methods. Understanding which method sits behind a policy is one of the most useful things a Medigap shopper can do before signing anything.

The three ways Medigap premiums are built

According to Medicare.gov, insurers use one of three approaches to price a Medigap policy:

Community-rated (also called "no-age-rated"). Everyone who buys the same policy from that insurer in that area pays roughly the same base premium, regardless of age. A 66-year-old and a 78-year-old buying the same plan pay a similar starting rate. The premium isn't raised because you get older, though it can still change for other reasons.

Issue-age-rated (also called "entry-age-rated"). The premium is based on the age you were when you bought the policy. Buy in at 65 and your rate is tied to that starting age. Buy the same plan at 72 and you'll generally start at a higher rate. But once you're in, the insurer doesn't raise your premium simply because you've had another birthday.

Attained-age-rated. The premium is based on your current age and is designed to go up as you age. It often looks like the cheapest option at 65, but the built-in age-based increases keep coming — at 70, 75, 80, and so on.

Why the price can go up even though the benefits can't

Here's the part that trips people up. Medigap benefits are locked in by federal standardization — a Plan G is a Plan G, and the insurer can't quietly trim what it covers. But the premium is a separate matter.

Under all three pricing methods, insurers are generally allowed to raise premiums for reasons that aren't about you personally, such as:

• Inflation and rising medical costs — hospitals, doctors and drugs cost more over time.
• Claims experience — if the group of people holding that policy uses more care than expected, the insurer can request a rate adjustment.

On top of that, attained-age policies add age-based increases as you grow older. So a policy that felt affordable at 65 can look very different at 80.

Which method will you be offered?

This is where it gets local. The pricing methods a company can offer depend on the insurer and on state law. Some states require community rating; others allow all three; a few restrict certain methods. Illinois shoppers in Belleville — which is in St. Clair County — will see options that reflect Illinois rules and the insurers doing business there.

The practical takeaway: don't assume the plan letter tells you the pricing method. Ask the insurer, in plain language, "Is this policy community-rated, issue-age-rated, or attained-age-rated?" Then ask how premiums have changed for existing policyholders over the last several years. That history is a better guide than the introductory rate on a brochure.

Timing matters more than most shoppers realize

The best window to buy Medigap is your six-month Medigap Open Enrollment Period, which starts the month you're 65 or older and enrolled in Part B. During that window, insurers can't turn you down or charge you more because of health conditions. Outside of it, in most states, medical underwriting can apply — meaning your health, not just your age, can affect whether you qualify and what you pay.

That's separate from the Medicare enrollment dates people hear about each fall: the Annual Enrollment Period (Oct. 15 – Dec. 7) and Medicare Advantage Open Enrollment (Jan. 1 – March 31). Those windows apply to Part D and Medicare Advantage, not to Medigap.

A quick word on Part D, since it often comes up

Medigap doesn't cover prescription drugs, so most Medigap enrollees also have a stand-alone Part D drug plan. For 2026, Part D has a $2,100 out-of-pocket cap, a maximum deductible of $615, and the old coverage gap ("donut hole") is gone — replaced in 2025 by a three-phase design. There's also the optional Medicare Prescription Payment Plan, which lets you spread drug costs across the calendar year in monthly installments. Higher-income enrollees may owe IRMAA surcharges, which for 2026 begin above $109,000 in income for a single filer.

Where to get answers you can trust

Before signing a Medigap application, Belleville readers can:

• Compare policies at medicare.gov, which lists the Medigap plans available in your ZIP code and shows which pricing method each insurer uses.
• Call 1-800-MEDICARE (1-800-633-4227), 24/7.
• Contact Illinois SHIP (Senior Health Insurance Program), the free, unbiased counseling service for Medicare beneficiaries in Illinois. SHIP counselors don't sell anything.