Guide · Reading the data
How to read insurance complaint ratios
What the NAIC complaint ratio actually measures, why a 1.0 baseline matters, and the numbers that should make you slow down before you buy.
- 1.0
- Median ratio
- >2.0
- Worth scrutiny
- <0.5
- Excellent
According to the National Association of Insurance Commissioners Market Conduct Annual Statement program (2024 data year, published 2026), PlainInsurer compiles complaint records reported through all 50 state insurance departments from more than 1,000 licensed insurers to explain how the complaint ratio is built. See our methodology for the full computation.
The short answer
A complaint ratio is a single number: justified complaints divided by market share. A 1.0 is the median, below 0.5 is excellent, and anything above 2.0 is a signal to look closer, but only ever within the same line of business.
- 1.0
- industry median
- <0.5
- excellent
- 2.0–3.0
- elevated
- >3.0
- proceed with caution
The ratio normalizes complaint volume by size, so a national carrier and a niche insurer can be compared fairly. NAIC MCAS, 2024 data year.
Denial rates vary widely between insurers
Highest and lowest claim-denial rates among large marketplace health insurers, a related consumer-friction signal you can read alongside the complaint ratio
- UnitedHealthcare Communi
UnitedHealthcare Community Plan, Inc.: 45.5% denied
45.5 % of claims denied
- Select Health of South C
Select Health of South Carolina: 45.5% denied
45.5 % of claims denied
- UnitedHealthcare of Ohio
UnitedHealthcare of Ohio, Inc.: 43.5% denied
43.5 % of claims denied
- UnitedHealthcare of Illi
UnitedHealthcare of Illinois, Inc.: 43.1% denied
43.1 % of claims denied
- AmeriHealth Caritas Nort
AmeriHealth Caritas North Carolina, Inc.: 43.0% denied
43 % of claims denied
- UnitedHealthcare of Ariz
UnitedHealthcare of Arizona, Inc.: 41.8% denied
41.8 % of claims denied
- Avera Health Plans 2.4
Avera Health Plans, Inc.: 2.4% denied
2.4 % of claims denied
- PacificSource Health Pla 3.5
PacificSource Health Plans: 3.5% denied
3.5 % of claims denied
- Sanford Health Plan 6.6
Sanford Health Plan: 6.6% denied
6.6 % of claims denied
- HealthPartners 6.7
HealthPartners Insurance Company: 6.7% denied
6.7 % of claims denied
- Priority Health 7.7
Priority Health: 7.7% denied
7.7 % of claims denied
- Providence Health Plan 8
Providence Health Plan: 8.0% denied
8 % of claims denied
What this shows The complaint ratio measures escalated disputes; the claim-denial rate measures how often a claim is refused outright. Reading both together tells genuine consumer harm from appropriate, expected denials.
What is a complaint ratio?
An insurance complaint ratio is a standardized measure of how many justified complaints an insurer receives relative to its size. It is calculated as the number of justified complaints divided by premiums written, in millions. The ratio is produced annually by the National Association of Insurance Commissioners (NAIC) through its Market Conduct Annual Statement (MCAS) program. All licensed insurers are required to submit complaint data to their state insurance departments, which report to NAIC.
What numbers are normal?
The median complaint ratio is approximately 1.0 - one justified complaint per million dollars in earned premiums. Use this as your baseline: below 0.5 is excellent, 0.5–1.0 is good, 1.0–2.0 is average to slightly elevated, 2.0–3.0 is worth investigating, and above 3.0 means proceed with caution.
Why bigger insurers look worse
Large national insurers process tens of millions of claims annually. Even with excellent processes, sheer volume produces more raw complaints. The complaint ratio normalizes for size by dividing by premiums, but very large insurers still tend to have higher raw complaint counts, which is why per-premium normalization matters.
What "justified" means
Not all complaints filed with state insurance departments are counted. A complaint is considered "justified" (or "upheld") when the state insurance department investigation finds that the insurer violated a policy provision, law, or regulation. Frivolous complaints or misunderstandings are excluded.
Beyond the headline ratio: what the components reveal
The complaint ratio is a single number computed from a numerator (justified complaints confirmed by the regulator) and a denominator (the carrier's market share). The numerator includes only complaints the regulator confirmed as justified, where the insurer was found to have acted contrary to law or contract, or where the regulator's intervention produced a different outcome. Unconfirmed complaints, inquiries, and complaints withdrawn before adjudication are not counted.
The denominator is computed from direct premiums written, separated by line of business (auto, home, life, health, commercial). Computing complaint ratios within line is essential because health insurance generates substantially more complaints per premium dollar than auto insurance. The complaint index reported on PlainInsurer reflects line-of-business-stratified ratios so health insurers are compared to health insurers and auto insurers to auto insurers, not across lines.
How to use this data when choosing an insurer
Look up the insurer and note the complaint ratio for your specific line of business. Compare it to the median (1.0) - anything above 2.0 deserves scrutiny. Cross-reference with AM Best or Standard & Poor's financial ratings, because a financially strong insurer with a high complaint ratio may pay claims but fight them first. Read state-specific data if available, and watch the trend: a rising complaint ratio is more concerning than a consistently elevated one.
What complaint ratios don't tell you
A high complaint ratio is a warning signal, not a verdict. It does not tell you whether individual claim decisions were correct, the financial stability of the insurer, coverage breadth or policy terms, the customer-service experience for non-claim interactions, or premium competitiveness. Use complaint data as one signal among many, combined with financial-strength ratings, coverage terms, and premium comparisons.
A practical framework
Four steps to read complaint ratios without being misled.
- Look up each candidate insurer and note its complaint ratio for your line. Browse insurers
- Compare within the same line of business, health to health, auto to auto. See rankings
- Pair the complaint ratio with the claim-denial rate before drawing conclusions. Denial rates explained
The complaint ratio describes how complaints are calculated and what they measure. It is not a recommendation about whether to file a complaint or purchase a policy. For decisions specific to your state, consult your state insurance department or a licensed agent.