Medicare·8 min read

Medigap vs Medicare Advantage in Illinois: 2026 Decision Guide

Illinois has unique Medigap rules that affect how easily you can switch later. Here's the trade-off most Illinois seniors should weigh.

Key Takeaways

1
Illinois does NOT offer guaranteed-issue Medigap outside the federal 6-month open enrollment window.
2
Switching FROM Advantage back to Original Medicare + Medigap later usually requires medical underwriting.
3
Most healthy 65-year-olds save the most over time with Medigap Plan G + a standalone Part D plan.
4
Most cost-conscious 65-year-olds save the most this year with $0 Medicare Advantage.

Illinois has limited Medigap protections

Federal law gives every newly Medicare-eligible person a 6-month open enrollment window for Medigap with no underwriting. After that, Illinois does not require carriers to issue Medigap policies on a guaranteed basis (unlike California, New York, or Connecticut).

Practical consequence: if you take Medicare Advantage at 65 and later want to switch to Medigap, you'll likely have to answer health questions and could be declined — especially if you've developed conditions like diabetes or cancer.

The straight cost comparison

Medigap Plan G in Illinois at age 65: roughly $130–$180/month, plus a standalone Part D plan ($30–$60/month). Total: ~$160–$240/month, with near-zero cost-sharing for any Medicare-covered service.

Medicare Advantage in Illinois at age 65: often $0 premium, but with copays for every doctor visit and a max out-of-pocket of $4,000–$8,500 per year. Total in a healthy year: under $500. Total in a bad health year: maxed out at the plan's MOOP.

Our usual recommendation

If you can comfortably afford Medigap premiums and you want predictability and freedom to see any provider, Plan G is hard to beat in Illinois — and starting at 65 locks in your underwriting.

If budget is the priority and your doctors are firmly in an Advantage network, $0 Advantage works — just understand the long-term switching consequences.

Medicare