Health insurance claim denials in Illinois
Insurers in Illinois denied 2,858,748 in-network claims — 15.6% of everything submitted. Just 58 reached independent external review, and 27.6% of those were overturned.
Illinois — in-network denial rate
15.6%
2,858,748 of 18,365,019 claims · 12 insurers reporting
Your rights in Illinois are federal. Every non-grandfathered plan must give you an internal appeal, and an independent external review for denials involving medical judgement, experimental or investigational determinations, or rescission of coverage. Your denial letter names the route and the deadline for your plan — that letter is the authority.
External review route in Illinois
State-run process
CMS lists Illinois as running its own external review process that meets the federal standards, so your independent review is handled through the state programme rather than the federal one. Source: CCIIO state external review table, checked 3 August 2026.
External review is not always free — but it is capped. There is no charge under the HHS-administered federal process. Where your insurer uses a contracted independent review organisation or a state process, a filing fee may apply, but it cannot exceed $25.
Insurers in Illinois
| Insurer | Denial rate | Denied | External reviews |
|---|---|---|---|
| UnitedHealthcare of Illinois, Inc. | 35.1% | 62,212 | — |
| Molina Healthcare of Illinois, Inc. | 27.5% | 389 | — |
| Cigna HealthCare of Illinois, Inc. | 24.3% | 97,334 | — |
| Medica Central Health Plan | 21.2% | 6,512 | — |
| Celtic Insurance Company | 18.7% | 273,732 | — |
| Oscar Health Plan, Inc. | 16.2% | 7,597 | — |
| Blue Cross Blue Shield of Illinois | 15.2% | 2,230,111 | 41 |
| Health Alliance Medical Plans, Inc. | 11.7% | 167,432 | 17 |
| MercyCare HMO, Inc. | 11.4% | 5,948 | — |
| Quartz Health Benefit Plans Corporation | 10.6% | 7,481 | — |
| Aetna Health Inc. (a PA corp.) | — | — | — |
| Aetna Life Insurance Company | — | — | — |
Everything you need for your appeal in Illinois: your two deadlines, the argument that fits your denial reason, an evidence checklist, and the external review request. Opens on screen the moment you pay.
This page presents federal statistics and a general description of appeal rights created by federal law. It is not legal, medical, or insurance advice, and no outcome is guaranteed. Your denial letter and plan documents govern your specific case. Free help is available from your state's Consumer Assistance Program and from the federal Marketplace at HealthCare.gov.