Medicare Advantage in Illinois: What to Know for 2027

44 Medicare Advantage plans in Illinois are changing for 2027, 44 plans are leaving and 23 plans are new. Use this guide to see how the plans work in Illinois and what to compare, in plain terms.

If Illinois Medicare feels like a moving target, here's why: availability is decided at the county level, not the state level. This guide meets that reality by going city by city.

Statewide, about 44% of Illinois Medicare members are in a Medicare Advantage plan rather than Original Medicare — an official figure that varies widely county to county.

Below you'll get the organizations serving Illinois, a jargon-free look at how Medicare works, 2027 costs, the enrollment calendar, free places to get help, and links into each city.

Advantage or Original Medicare? The basic fork

Every Medicare decision in Illinois branches from one question: do you want your coverage delivered through a private Medicare Advantage plan, or do you want to stay with Original Medicare and build around it?

Go the Medicare Advantage route and a private plan (approved by Medicare) handles your Part A and Part B, typically folds in drug coverage — within a network and a county-based service area.

Stay with Original Medicare and you keep nationwide provider freedom, then usually add a stand-alone Part D drug plan and often a Medigap policy to cover what Original Medicare doesn't.

There's no single winner here — it comes down to your providers, your medications, and your budget. We explain the trade-offs and leave the choice to you; we don't rank plans.

The 2027 numbers, from shared to plan-specific

Start with what's fixed for everyone. The standard Part B premium is $202.90 per month in 2026 (2026 amount; 2027 figure will be posted when CMS releases it), and Part A is premium-free for most people who paid Medicare taxes long enough while working.

On the drug side, Part D has real guardrails for 2027: a deductible capped at $700 and, a hard $2,400 ceiling on your out-of-pocket costs for covered prescriptions — the old coverage gap is gone.

Higher earners pay more for Parts B and D through an income-related adjustment called IRMAA, which for 2026 starts above $109,000 in annual income for an individual and is based on your 2024 tax return. Most people fall below that line and pay the standard amounts. The 2027 brackets will be posted when CMS releases them.

Everything past that is plan-specific: the premiums, copays, and coverage details of an individual Advantage or Medigap plan change from plan to plan and year to year. Rather than quote or rank those, we point you to Medicare's Plan Finder and a licensed agent for your exact numbers.

Your Medicare enrollment calendar

The dates that follow are set federally, so they don't change from state to state — only your personal timing does.

It starts with your Initial Enrollment Period — the 7-month window around your 65th birthday month — the window around turning 65 when you first sign up. Missing it can mean late penalties that stick around, so it's the one not to sleep on.

After that, the big recurring window is the Annual Enrollment Period, October 15 – December 7, when anyone can join, switch, or drop an Advantage or Part D plan for a January 1 start. And if you're already in an Advantage plan, the Medicare Advantage Open Enrollment (January 1 – March 31) gives you one more chance to change course.

Life events — a move, a loss of other coverage — can also trigger a Special Enrollment Period. The calendar below shows the whole year at a glance.

Where to get free, unbiased help near Illinois

Good Medicare help exists and it's free — you don't have to figure this out solo or pay for guidance.

For official specifics and the Plan Finder tool, go straight to Medicare.gov or 1-800-MEDICARE (TTY 1-877-486-2048). And a licensed agent can compare options and handle the paperwork with you.

One note on who we are: MyMedicarePlans.org is an independent, privately owned educational resource — not Medicare, not a government agency, and not affiliated with one. Our job is to help you get oriented, then hand you off to the official sources and licensed professionals for plan decisions.

Illinois cities

Pick your city for the county-level picture, the companies active in your area, and local guides: