Best Medicare Supplement Plans in Illinois 2026
Illinois has over ~750,000 Medigap enrollees - one of the largest markets in the country. Plan G starts at $113/mo in Chicago. We compared 30+ carriers to find the best coverage for Illinois seniors.
Blue Cross Blue Shield of Illinois Dominates the Market
BCBS of Illinois holds a remarkable 48.2% of the state's Medigap market - the largest share of any single carrier in any state we've reviewed. While BCBS Illinois is not in NerdWallet's national top-rated list, its dominant local presence, strong brand recognition, and broad provider network make it a carrier worth comparing alongside the national options listed below.
More than 750,000 people in Illinois have Medicare Supplement Insurance, or Medigap - making Illinois one of the largest Medigap markets in the country. Plan G starts at $113 per month in Chicago for a 65-year-old female nonsmoker, offering strong value in a competitive market. Illinois has over 30 carriers licensed to sell Medigap, giving enrollees a wide range of options at various price points.
One notable feature of the Illinois market is the unusually high adoption of Plan F (44% of enrollees), reflecting a large base of legacy enrollees who enrolled before Plan F was discontinued for new Medicare beneficiaries in 2020. For new enrollees, Plan G is the most comprehensive option available, covering all out-of-pocket costs except the annual Part B deductible ($283 in 2026). Illinois uses attained-age rating, meaning premiums increase as you age, so enrolling during your Open Enrollment Period at 65 is the best strategy.
Compare the Best Medicare Supplement Plans in Illinois
Our top-rated Medigap carriers in Illinois, ranked by the MedicareFAQ Score. Premiums shown are for a 65-year-old female nonsmoker in Chicago. Rates in Springfield, Rockford, and other regions may vary.
State Farm
Plan G
$197/mo
Plan N
$149/mo
AM Best
A++
Plans
6 types
AARP/UnitedHealthcare
Plan G
$138/mo
Plan N
$93/mo
AM Best
A+
Plans
8 types
HealthSpring (formerly Cigna)
Plan G
$118/mo
Plan N
$78/mo
AM Best
A
Plans
4 types
Mutual of Omaha
Plan G
$177/mo
Plan N
$121/mo
AM Best
A+
Plans
4 types
Wellabe
Plan G
$124/mo
Plan N
$94/mo
AM Best
A-
Plans
4 types
Medicare Supplement Prices in Illinois
Sample monthly premiums from our top-scoring carriers. Rates shown are for a 65-year-old female nonsmoker in Chicago and include available household discounts. Illinois uses attained-age rating - premiums will increase as you age. Rates in Springfield, Rockford, and other cities may differ.
| Insurance Company | Plan G Monthly | Plan N Monthly | MedicareFAQ Score |
|---|---|---|---|
| State Farm | $197 | $149 | 4.9 |
| AARP/UnitedHealthcare | $138 | $93 | 4.7 |
| HealthSpring (formerly Cigna) | $118 | $78 | 4.5 |
| Mutual of Omaha | $177 | $121 | 4.4 |
| Wellabe | $124 | $94 | 4.2 |
Lowest available in Illinois (Chicago): Plan G from $113/mo | Plan N from $78/mo | Source: CMS Medicare Plan Finder, NerdWallet Feb 2026
Plan G vs. Plan N in Illinois
Plan G and Plan N are the two most popular Medicare Supplement plans for new enrollees in Illinois. Here is how they compare.
| Coverage Feature | Plan G | Plan N |
|---|---|---|
| Part A hospital coinsurance | Covered | Covered |
| Part B coinsurance (20%) | Covered | Covered* |
| Part A deductible ($1,736) | Covered | Covered |
| Part B deductible ($283) | Not covered | Not covered |
| Part B excess charges | Covered | Not covered |
| Skilled nursing coinsurance | Covered | Covered |
| Foreign travel emergency | Covered | Covered |
| Office visit copay | $0 | Up to $20 |
| ER copay (no admission) | $0 | Up to $50 |
| Avg. monthly premium (Chicago) | $151/mo | $107/mo |
*Plan N covers Part B coinsurance but may charge up to $20 for some office visits and up to $50 for ER visits that do not result in inpatient admission.
BCBS of Illinois holds 48.2% of the market but is not in the national top-rated lists - always compare it alongside national carriers. HealthSpring offers the lowest Plan G in Chicago at $118/mo but has a far-higher-than-expected complaint rate. Wellabe at $124/mo is a better middle ground. If you are currently on Plan F, you cannot switch to Plan G without passing medical underwriting after your OEP ends - so if you are happy with your coverage, staying put may be the right call. State Farm is headquartered in Bloomington, IL, giving it a strong local agent presence throughout the state.
Illinois Medigap Rules You Should Know
6-Month Open Enrollment Period
Your Medigap Open Enrollment Period is a one-time 6-month window that starts the first month you are 65 or older and enrolled in Medicare Part B. During this period, carriers cannot deny you coverage or charge more due to pre-existing health conditions. This is the best time to enroll in Medigap in Illinois.
No Birthday Rule in Illinois
Illinois does not have a birthday rule. Unlike California, which allows enrollees to switch to an equal or lesser plan during a 60-day window each year around their birthday, Illinois enrollees can only switch Medigap plans after their OEP by passing medical underwriting. This makes your initial enrollment decision especially important.
Attained-Age Rating
Illinois uses attained-age rating, which means your Medigap premium increases as you get older. Premiums are based on your current age and rise each year. Enrolling during your OEP at age 65 is the best strategy to lock in the lowest possible starting rate.
Plan F Legacy Enrollees
Illinois has one of the highest Plan F adoption rates in the country at 44%. Plan F is no longer available to new Medicare enrollees who became eligible on or after January 1, 2020. Existing Plan F enrollees can keep their coverage indefinitely, but cannot switch to Plan G without passing medical underwriting after their OEP ends. Plan G is the most comprehensive option available to new enrollees.
Illinois SHIP - Free Medicare Counseling
Illinois has a Senior Health Insurance Program (SHIP) that provides free, unbiased Medicare counseling from trained volunteers. SHIP counselors can help you compare Medigap plans, understand your options, and navigate enrollment. The program is available to all Illinois Medicare beneficiaries and their families at no cost.
Regulated by the Illinois Department of Insurance
All Medigap plans in Illinois are regulated by the Illinois Department of Insurance (IDOI). The IDOI maintains consumer resources for comparing plans and handles complaints against carriers. Illinois also enforces a 30-day free-look period, allowing you to return a new policy for a full refund if you are not satisfied.
MedicareFAQ Scoring Methodology
The MedicareFAQ Score rates Medicare Supplement carriers on a scale of 1.0 to 5.0 based on five key factors. Our ratings are independent and not influenced by advertising relationships.
Financial Strength
AM Best rating and outlook stability. A++ carriers score highest.
Pricing Competitiveness
Plan G and Plan N premiums compared to the Illinois state average for a 65-year-old female nonsmoker in Chicago.
Plan Availability
Number of standardized Medigap plan letters offered in Illinois.
Consumer Satisfaction
NAIC complaint ratio relative to market share and customer review sentiment.
Discounts & Value
Household, loyalty, payment mode, and other available premium discounts.
Last updated: February 2026 | Data sources: CMS Medicare Plan Finder, AM Best, NAIC Complaint Database, NerdWallet, Illinois Department of Insurance
Frequently Asked Questions
Find the Best Medigap Rate in Your Illinois ZIP Code
Illinois has over 30 Medigap carriers competing for your business. Enter your ZIP code to see exact rates from all available carriers in your area - and remember, your Open Enrollment Period is the best time to lock in coverage without medical underwriting.