Glossary

NAIC complaint index

A score comparing an insurer's share of consumer complaints with its share of premiums; 1.00 is the national baseline and lower is better.

Also called: complaint ratio, complaint index

The NAIC complaint index measures how many complaints an insurer draws relative to its size. State insurance departments report closed consumer complaints to the NAIC, which compares each company's share of complaints with its share of premiums in a line of business, such as private passenger auto.

The formula is: complaint index = company's share of complaints ÷ company's share of premiums. A company with 2% of the auto premiums and 2% of the auto complaints scores 1.00, the national baseline. One with 2% of premiums and 1% of complaints scores 0.50, half as many complaints as its size predicts; one with 4% of complaints scores 2.00 (hypothetical figures).

Read the index with care. Small insurers can swing far above or below 1.00 on a handful of complaints, so look at several years and at the raw count. Indexes are calculated for each legal company, not the brand, so a large group may show several entries with different results. A complaint is not proof of wrongdoing, so look at the reasons listed, such as claim delays or unsatisfactory settlements. And a low index says nothing about whether the company can pay claims; for that, check its AM Best rating. See The NAIC complaint index: how to look up an insurer.

Last reviewed October 4, 2026

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Related terms

NAIC The standard-setting organization of the chief insurance regulators of the 50 states, D.C. and five U.S. territories, founded in 1871. State department of insurance The state agency that licenses insurers and agents, reviews rates and policy forms, monitors solvency and handles consumer complaints. AM Best rating A letter grade from rating agency AM Best on an insurer's ability to pay claims, running from A++ (Superior) down to D (Poor). Direct written premium The total premium an insurer charges on policies it writes in a period, before reinsurance, used to measure market share and company size. Bad faith An insurer's unreasonable handling of a claim, such as denying, delaying or underpaying without a proper basis, which can expose it to damages.

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