Illinois Medigap plans (also called Medicare Supplement plans) cover the gaps in Original Medicare, including deductibles, copays, and coinsurance that would otherwise come out of your pocket. This comprehensive Illinois Medigap guide covers available plans, average premiums, top carriers, the birthday rule, guaranteed issue rights, and how to choose between Plan G, Plan N, and other options. Whether you are approaching your initial Medigap Open Enrollment or considering a plan switch, understanding Illinois Medigap rules helps you make a confident decision.
All information verified against CMS data and state sources as of April 2026.
In This Illinois Medigap Guide:
Medigap Plans Available in Illinois
Standardized plans: A, B, C, D, F, G, K, L, M, N
Every Medigap plan with the same letter provides identical benefits regardless of which carrier sells it. Plan G from one company covers the exact same medical costs as Plan G from another company. The only difference is the premium and the customer service experience. This standardization makes comparison shopping straightforward.
Plan F: Still available in Illinois for beneficiaries who became eligible for Medicare before January 1, 2020. Plan F covers all gaps including the Part B deductible. New enrollees after 2020 cannot purchase Plan F.
High-Deductible Plan G: Available in Illinois. You pay a higher annual deductible before benefits kick in, but monthly premiums are significantly lower than standard Plan G.
Illinois Medigap Rates: Plan G & Plan N
| Plan | Age 65 | Age 70 | Age 75 |
|---|---|---|---|
| Plan G | $155/mo | Varies | Varies |
These are approximate averages. Your actual premium depends on your carrier, zip code, age, gender, and tobacco use. Always compare quotes from at least three carriers before choosing.
How Illinois Medigap Pricing Works
Illinois uses attained-age-rated Medigap pricing. Your premium increases as you age. This means your Medigap costs will rise over time, making it especially important to compare rates annually and switch carriers during open enrollment windows if available.
Household discount: Many Medigap carriers in Illinois offer 5-12% household or spousal discounts when two people in the same household both have Medigap policies.
Plan G vs Plan N in Illinois
Plan G and Plan N are the two most popular Medigap plans in Illinois. Here is how they compare:
| Feature | Plan G | Plan N |
|---|---|---|
| Part B Deductible | Not covered (you pay $240/year in 2026) | Not covered |
| Part B Copay | Covered (no copays) | Up to $20 copay for office visits, up to $50 for ER visits not resulting in admission |
| Part B Excess Charges | Covered | Not covered |
| Monthly Premium | Higher | Lower (typically 15-25% less than Plan G) |
| Best For | Predictable costs, no copays | Lower premiums, okay with small copays |
Bottom line: If you want the most comprehensive coverage with no copays at the doctor, choose Plan G. If you prefer lower monthly premiums and do not mind occasional $20 copays, Plan N offers strong coverage at a lower cost.
Top Medigap Carriers in Illinois
Top Medigap carriers in Illinois:
- AARP/UnitedHealthcare
- Blue Cross Blue Shield of Illinois
- Mutual of Omaha
- MedMutual Protect (Wellabe)
- State Farm
MedMutual Protect typically offers among the lowest Plan G premiums in Illinois. However, the cheapest carrier varies by zip code and age bracket.
When comparing Medigap carriers, the benefits are identical for the same plan letter. Focus on premium cost, AM Best financial strength rating (A or higher is strong), customer service reputation, and rate increase history.
Rate increase trend: Illinois Medigap carriers have historically had average rate increases compared to the national average.
Illinois Medigap Switching Rights
Illinois birthday rule: Illinois enrollees aged 65-75 get a 45-day annual window starting on their birthday to switch to a Medigap plan with equal or lesser benefits from their current insurer or an affiliate insurer without medical underwriting. Effective since January 1 2022. Does not apply after age 75. This annual switching window allows you to change Medigap plans without medical underwriting, potentially finding lower premiums.
Guaranteed Issue Rights in Illinois
Federal law provides guaranteed issue rights in specific situations where you can buy a Medigap plan without medical underwriting:
- Losing employer/union coverage
- Your Medicare Advantage plan leaves your area
- You joined an MA plan when first eligible and want to switch back within 12 months (trial right)
- Your Medigap carrier goes bankrupt
Illinois-specific guaranteed issue protections: BCBSIL offers year-round guaranteed issue for Plans A and G and N for beneficiaries age 65 and older, under-65 Medicare beneficiaries get an annual enrollment window October 15 through December 7 for BCBSIL guaranteed issue plans, 45-day birthday rule annual switch window for ages 65-75
Additional Illinois Medigap rules: Birthday rule allows annual Medigap switching for ages 65-75 with 45-day window. BCBSIL offers year-round guaranteed issue enrollment for Plans A G and N. Under-65 Medicare beneficiaries have annual Oct 15-Dec 7 enrollment window for BCBSIL guaranteed issue plans. Illinois requires all rate filings be submitted through SERFF and approved by the Director. High-deductible Plan G has a 2950 dollar deductible for 2026. Plans C and F only available to those Medicare-eligible before January 1 2020.
Common Medigap Mistakes in Illinois
- Missing your OEP: Your 6-month Medigap Open Enrollment Period is your best window. After it closes, carriers can deny you or charge higher premiums based on health.
- Choosing by carrier name alone: Medigap plans are standardized. A well-known brand’s Plan G costs more but covers the exact same benefits as a smaller carrier’s Plan G.
- Ignoring rate increase history: Some carriers offer low introductory rates then raise premiums aggressively. Ask for 5-year rate increase history before buying.
- Not comparing at least 3 carriers: Premium differences of 30-50% between carriers for the same plan letter are common.
- Confusing Medigap with Medicare Advantage: They are different products. You cannot have both simultaneously (except during limited trial rights).
Compare Illinois Medigap Rates
Ready to compare Medigap plans in Illinois? Use the official Medicare Plan Finder or contact your local SHIP counselor.
Official Sources & Resources
- Medicare.gov: medicare.gov
- Illinois Department of Insurance: https://idoi.illinois.gov
- NAIC Medigap Shopping Guide: naic.org
- CMS Medicare & You Handbook: Medicare & You (PDF)
Last verified April 2026. Contact us if you notice outdated information.