Every year, thousands of US patients file complaints against their health insurance companies. Denied claims, prior authorization delays, and billing errors top the list of frustrations. But which insurer receives the most complaints?
Using the latest data from the National Association of Insurance Commissioners (NAIC) and consumer advocacy groups like the Center for Justice & Democracy, we break down the 2025-2026 complaint rankings.
The Short Answer
For the third year running, UnitedHealthcare receives the highest volume of customer complaints. However, when adjusted for market share, Cigna and Anthem (Elevance) often have the highest complaint ratios (number of complaints per million members).
Top 5 Insurers by Complaint Volume (2026)
| Rank | Insurance Company | Most Common Complaint | Complaint Index* |
|---|---|---|---|
| 1 | UnitedHealthcare | Claim denials (post-service) | 1.89 |
| 2 | Anthem (Elevance) | Prior authorization delays | 2.10 |
| 3 | Cigna | Out-of-network billing disputes | 2.45 |
| 4 | Aetna (CVS Health) | Prescription drug coverage | 1.65 |
| 5 | Humana | Medicare Advantage billing | 1.90 |
**Complaint Index: National average is 1.0. Higher number = more complaints than expected for their market size.*
Why Patients Complain Most About These Insurers
1. UnitedHealthcare (UHC)
The largest US insurer also gets the most complaints. Patients report UHC denies 12-15% of in-network claims on first submission—double the industry average. Common phrases in complaints: “They changed the policy after I got care.”
2. Cigna
Cigna’s “Payer of Last Resort” policies frustrate patients. Many complain that Cigna demands other insurers (auto, worker’s comp) pay first, delaying care by weeks. Their complaint ratio (2.45) is the highest among major insurers.
3. Anthem (Elevance)
Anthem leads in prior authorization complaints. Patients say Anthem requires approvals for routine procedures (e.g., MRIs, colonoscopies) and often takes >72 hours to respond. Some states have fined Anthem for violating timely access laws.
What This Means for Your Practice
If your medical practice bills any of the above insurers, expect:
- Higher denial rates (especially for UHC and Cigna)
- Longer A/R days (Anthem prior auths delay payments 30+ days)
- Frustrated patients blaming your front desk for insurance delays
Solution: A dedicated RCM partner like All State RCM can pre-verify benefits, track prior auths, and appeal denials before they hit your aging report. We keep your rejection rate below 1% and recover claims others write off as lost.
The Bottom Line for Patients
UnitedHealthcare generates the most total complaints, but Cigna has the worst per-member complaint ratio. Always check NAIC complaint indexes before choosing a plan—especially for Medicare Advantage or small business coverage.
Need Help Filing a Complaint?
Patients can file complaints with:
- Your State Department of Insurance (fastest resolution)
- CMS (for Medicare/Medicaid issues)
- NAIC Consumer Complaint Database (public record)
