Medicare Supplement

Medigap in Chicago: the standardized letters Illinois shoppers can actually pick

CHICAGO — If you have Original Medicare and you are looking at a Medicare Supplement policy — often called Medigap — the first thing to know is that the coverage itself is set by the federal government, not by the insurance company. Every Medigap policy sold in Illinois falls under a standardized letter, and a Plan G from one insurer covers the same medical items as a Plan G from any other insurer. What can differ is the price, the customer service, and how the insurer decides to raise rates over time.

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That is the piece Chicago shoppers most often miss, so this guide walks through which letters you can still buy in Illinois, how a Medigap policy fits with Part B and Part D, and where to look for the insurer list that applies to your ZIP code.

What "standardized" really means

Since 1992, federal law has required Medigap policies to be sold as standardized plans identified by a letter. In Illinois — like most states — the letters available to people newly eligible today are A, B, D, G, high-deductible G, K, L, M and N. Massachusetts, Minnesota and Wisconsin use their own systems, but Illinois follows the federal letters.

The benefits inside each letter are fixed. A Plan N is a Plan N. What is not fixed is the premium, and that is where shopping matters.

The letters open to new Medicare enrollees in Illinois

If you became eligible for Medicare on or after January 1, 2020, Plans C and F are off the table. They were closed to newly eligible enrollees under federal law because they covered the Part B deductible. If you were eligible before that date, you may still be able to buy C or F.

For everyone else, the choices in Illinois are:

• Plans A and B — the most basic packages.
• Plans D, G and N — broader coverage; Plan G is the most comprehensive currently available to new enrollees.
• High-deductible Plan G — pays after you meet a yearly deductible set by CMS.
• Plans K and L — cost-sharing plans with an annual out-of-pocket limit.
• Plan M — a middle-ground option.

The Medicare & You handbook and medicare.gov show a side-by-side chart of what each letter covers.

How Medigap fits with Original Medicare and Part D

A Medigap policy only works alongside Original Medicare. It helps pay some of the out-of-pocket costs Parts A and B leave behind — things like coinsurance and, for some letters, the Part A deductible. It does not work with a Medicare Advantage plan; in fact, it is illegal for an agent to sell you a Medigap policy if you are staying in an Advantage plan.

Medigap policies sold today do not include prescription drug coverage. If you want help with drug costs, you enroll separately in a stand-alone Part D plan. A few 2026 Part D facts worth keeping in mind:

• The out-of-pocket cap for covered drugs is $2,100.
• The maximum Part D deductible is $615.
• The old coverage gap ("donut hole") is gone as of 2025 — there are now three payment phases.
• The Medicare Prescription Payment Plan lets you spread drug costs across the calendar year in monthly installments if you opt in.

Higher-income enrollees also pay IRMAA surcharges on Part B and Part D; for a single filer in 2026, those start above $109,000 in income.

How Illinois insurers price the same letter differently

Two Plan Gs cover the same medical claims, but they can be priced with very different methods. In general, insurers use one of three approaches:

• Community-rated — everyone pays the same premium regardless of age.
• Issue-age-rated — your premium is based on your age when you buy in.
• Attained-age-rated — your premium goes up as you get older.

Over ten or twenty years, the pricing method can matter as much as the starting price. The Illinois Department of Insurance publishes a Medigap rate comparison guide that shows how each insurer prices in the state, and the state SHIP (Senior Health Insurance Program) can walk you through it at no cost.

Timing: when you can buy without medical questions

Your strongest protection is the federal Medigap open enrollment period: six months that begin the month you are 65 or older and enrolled in Part B. During that window, insurers in Illinois must sell you any Medigap policy they offer at their best available rate, regardless of your health.

Outside that window, insurers can generally use medical underwriting — meaning they can charge more or decline you — unless you qualify for a federal guaranteed-issue right (for example, if your Medicare Advantage plan leaves your area). Illinois may offer additional protections beyond federal law, so check with the Illinois Department of Insurance or your SHIP counselor before you assume you can switch freely.

Finding the insurers that sell in Chicago

Chicago is in Cook County, and Medigap availability is regulated at the state level. Because Illinois insurer information is not included in the table on this page, the best two starting points are:

1. Medicare.gov Medigap policy search. Enter your ZIP code to see which insurers offer which letters in your area, along with sample premiums. 2. Illinois Department of Insurance Medigap rate guide. This shows every licensed Medigap insurer in the state and how they price by age.

Then call the insurers directly for a firm quote, or work with a licensed independent agent who can present multiple companies.