Guide · Reading the data
How to read insurance complaint ratios
What the NAIC complaint ratio measures, why the 1.0 median is the baseline, and how elevated values are interpreted within a single line of business.
- 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. Data as of August 2026.
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
- CareSource North Carolin
CareSource North Carolina Co.: 37.0% denied
37 % of claims denied
- Select Health of South C
Select Health of South Carolina: 36.5% denied
37 % of claims denied
- Oscar Buckeye State Insu
Oscar Buckeye State Insurance Corp.: 36.4% denied
36 % of claims denied
- UnitedHealthcare Communi
UnitedHealthcare Community Plan, Inc.: 35.6% denied
36 % of claims denied
- Oscar Health Plan
Oscar Health Plan, Inc.: 34.6% denied
35 % of claims denied
- UnitedHealthcare of Okla
UnitedHealthcare of Oklahoma, Inc.: 33.7% denied
34 % of claims denied
- Avera Health Plans 4
Avera Health Plans, Inc.: 3.5% denied
4 % of claims denied
- Sanford Health Plan 6
Sanford Health Plan: 5.5% denied
6 % of claims denied
- HealthPartners 7
HealthPartners Insurance Company: 6.6% denied
7 % of claims denied
- Capital Health Plan 7
Capital Health Plan: 7.1% denied
7 % of claims denied
- Matthew Thornton Hlth Pl 8
Matthew Thornton Hlth Plan(Anthem BCBS): 8.0% denied
8 % of claims denied
- Providence Health Plan 8
Providence Health Plan: 8.3% 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.
Why complaint data matters more than reviews
Consumer reviews on retail sites and Google capture satisfaction extremes, people who love or hate their experience. Complaint data from NAIC captures something different: formal complaints filed through state insurance departments, typically after a dispute the policyholder could not resolve directly. These are not opinion surveys; they are documented grievances processed by regulators.
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 complaint ratios are compared in this registry
Each insurer profile lists the complaint ratio for a specific line of business. Values are read against the 1.0 median within that line; ratios above 2.0 are elevated relative to peers. Financial-strength ratings (AM Best, S&P) measure solvency, not claim-handling friction, so a financially strong carrier can still show an elevated complaint ratio. State-specific rows, when present, can diverge from the national figure. Multi-year trends separate a one-year spike from a sustained elevation.
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.
Trend analysis: improving vs. deteriorating insurers
A single year's complaint ratio is a snapshot. When available, multi-year trends are far more informative. An insurer whose ratio has declined over several years is demonstrating genuine improvement; one whose ratio has risen may be experiencing growth-related service degradation, coverage-restriction changes, or claims-department workforce issues. For smaller carriers, a single high-profile dispute can move the metric noticeably, which is another reason to read the trend rather than react to one year's noise.
What the registry surfaces
Three reads that keep the complaint column in context.
- Insurer profiles list line-specific complaint ratios from NAIC MCAS. Browse insurers
- Rankings keep comparisons inside one line of business. See rankings
- Claim-denial rates are a separate CMS column from complaint ratios. Denial rates explained
The complaint ratio describes how justified complaints are calculated and what they measure. It is not a recommendation to file a complaint or purchase a policy.