If you live in Illinois, you have many options for Medicare coverage, including Original Medicare (parts A and B), Medicare Advantage (Part C), and Medicare Part D (drug coverage).

Medicare is a federal health insurance program that helps people ages 65 years and older pay for necessary medical care. You may also be eligible if you are younger than age 65 years and living with certain disabilities.

This article reviews all of the Medicare options in Illinois, including Medicare Advantage and Medigap plans, plus what to consider as you shop for coverage.

2025 Medicare trends in Illinois

The Centers for Medicare & Medicaid Services (CMS) reported the following information on Medicare trends in Illinois for the 2025 plan year:

  • A total of 2,390,359 residents of Illinois are enrolled in Medicare.
  • The average Medicare Advantage monthly premium decreased compared with last year, changing from $12.01 in 2024 to $8.39 in 2025.
  • There are 157 Medicare Advantage plans available in Illinois for 2025, compared with 165 plans in 2024.
  • All Illinois residents with Medicare have access to a Medicare Advantage plan, including plans with $0 premiums.
  • There are 10 Medigap plans offered in Illinois for 2025. Plan C and F are no longer available to new Medicare members.

When you sign up for Medicare in Illinois, you can choose either Original Medicare (parts A and B) or Medicare Advantage (Part C). You may also purchase a Medicare Part D (prescription drug coverage) plan and a supplemental insurance plan, also called Medigap.

Original Medicare

Original Medicare, sometimes called traditional Medicare, is run by the government. It includes Part A (hospital insurance) and Part B (medical insurance).

Part A covers hospital stays and other inpatient care, while Part B covers many necessary medical services, including doctors’ visits and preventive services.

Medicare Part D

Medicare Part D is Medicare’s prescription drug coverage. You may purchase a Medicare Part D plan from Medicare or as part of a Medicare Advantage plan.

Medicare Advantage plans

Medicare Advantage (Part C) plans give you another way to get your Medicare coverage. These plans are offered by private insurance companies, and they include all services under Medicare parts A and B.

Medicare Advantage plans in Illinois may offer many other benefits that aren’t included in Original Medicare, such as:

Many Medicare Advantage plans are available to Illinois residents. The following insurance carriers are some that offer Medicare Advantage plans in Illinois:

Medicare Advantage plan offerings vary by county. To research plans in your area, you can use this online Medicare tool. You can enter your ZIP code when searching for plans where you live.

Medicare supplement plans (Medigap)

If you enroll in Original Medicare, you can choose to sign up for some additional types of coverage. Medigap policies cover some of the healthcare costs that Original Medicare doesn’t pay for, such as copayments and deductibles.

In Illinois, many insurance companies offer Medigap plans. Some of the companies offering Medigap plans in Illinois include:

Illinois consumers have 10 different types of Medigap plans to choose from. It’s worth noting that you cannot have Medigap and a Medicare Advantage plan at the same time. Medigap helps cover costs of Original Medicare only.

There are many things to consider as you evaluate the many Medicare plans in Illinois. To find the plan that best suits your needs, consider these factors:

  • Covered services: Medicare Advantage plans may cover services that Original Medicare doesn’t, such as dental, vision, or hearing care. Some even offer perks, such as gym memberships. Look for plans that cover the services you want or need.
  • Cost: The cost of Medicare Advantage plans varies. For some plans, you may be charged a monthly plan premium in addition to the Medicare Part B premium. Copayments, coinsurance, and deductibles will also affect your out-of-pocket costs.
  • Provider network: If you join a Medicare Advantage plan, you may need to get care from doctors and hospitals in your plan’s network. You may want to ask your current healthcare professionals whether they participate in plans you are considering.
  • Service area: Original Medicare provides nationwide coverage, while Medicare Advantage plans serve more limited areas. If you plan to travel, you may prefer a Medicare plan that offers travel or visitor benefits.
  • Ratings: Every year, the Centers for Medicare & Medicaid Services (CMS) rates plans from 1 to 5 stars. These star ratings are based on customer service, quality of care, and other factors. To check a plan’s rating, go to CMS.gov and download the Star Ratings Fact Sheet.

If you’re eligible for Medicare, you can sign up at certain times throughout the year. These times include:

  • Initial enrollment period: This 7-month period is available for people who become eligible for Medicare when they turn age 65 years. It starts 3 months before the month you turn 65 years old and ends 3 months after your birth month.
  • Annual Medicare open enrollment period: The annual open enrollment period runs from October 15 to December 7. If you sign up for a Medicare Advantage plan during this period, your new coverage will start on January 1.
  • Medicare Advantage open enrollment period: From January 1 to March 31 every year, you can switch to a different Medicare Advantage plan. If you make changes, your new coverage starts on the first day of the month after the insurer gets your request.
  • Special enrollment period: If you experience certain life events, you’re allowed to sign up for Medicare outside of the annual enrollment periods. You could have a special enrollment period if you lose your employer health coverage, for example.

In some circumstances, you may be signed up for Medicare automatically. If you’re eligible for Medicare due to a disability, you’ll be enrolled after you receive Social Security Disability Insurance (SSDI) checks for 24 months. If you get Railroad Retirement Board (RRB) benefits or Social Security retirement benefits, you’ll be enrolled when you turn 65 years old.

What should I do next?

When you’re ready to shop for a Medicare plan, here’s what you can do next:

  • To sign up for Medicare parts A and B, contact the Social Security Administration. You can call 800-772-1213, visit your local Social Security office, or use Social Security’s online Medicare application.
  • If you’re interested in Medicare Advantage plans in Illinois, you can compare plans at Medicare.gov. If you see a plan you like, you can enroll online.

Medicare eligibility guidelines

The eligibility rules for Medicare vary depending on your age. If you’re younger than age 65 years, you may become eligible in either of these situations:

If you’re turning 65 years old, you’re eligible for Medicare in Illinois in either of these situations:

  • You live in the United States and are a U.S. citizen or permanent resident.
  • You already receive Social Security retirement benefits or qualify for them.

Medicare is a complex program, but there are resources that can help you understand your options.

For more information about Medicare in Illinois, you can contact the Senior Health Insurance Program, which provides free, one-on-one counseling about Medicare and other health insurance options.

If you live in Illinois, you have a number of different Medicare options to choose from.

You can sign up for Original Medicare (parts A and B) and decide whether to add Medicare Part D (drug coverage) or a supplemental insurance plan, known as Medigap.

You may also decide to enroll in a Medicare Advantage (Part C) plan. Private insurance companies offer many types of Medicare Advantage and Medigap plans in Illinois. But remember, you cannot have Medigap and a Medicare Advantage plan at the same time.