21 tracked auto insurance carriers ranked by NAIC complaint index (higher = more regulator-confirmed complaints relative to premium volume). Median for this line: 1.43.
Auto Insurance · NAIC MCAS 2026
Auto Insurance: 21 tracked carriers, median complaint index 1.43; Gainsco Insurance leads the high end at 3.87, USAA the low end at 0.34.
Registry facts from retained NAIC extracts, not a buy/sell recommendation.
Across 51 jurisdictions, average expenditure moved from $1,015 (2019) to $1,191 (2023), a +17.4% endpoint change. This is a cost blend, not a complaint index.
Named endpoints
Among 21 auto insurance carriers with a ratio, Gainsco Insurance posts the highest NAIC complaint index (3.87, ~2.7× the line median of 1.43). USAA posts the lowest (0.34, about 76% below the median). Endpoints identify the range of the retained MCAS set; they are not purchase recommendations.
Complaint-index span
Among 21 auto insurance carriers with a reported NAIC complaint index, the observed range is 0.34 to 3.87 (span 3.53). The highest index sits about 2.7× the line median of 1.43. That gap is a property of this line's reported set, not a cross-line comparison.
2024 premium concentration
In the 2024 auto insurance market-share release PlainInsurer retains, the five largest groups account for 63.5% of written premium. The largest named group is State Farm Group at 18.9% of the 2024 NAIC market-share table. Complaint-index ranks below are company-level MCAS rows and are not the same unit as group market share.
Companion auto evidence
Auto is the only line where PlainInsurer also publishes a 51-jurisdiction NAIC average-expenditure series (2019–2023 retained releases) at /auto-rates/. That surface measures statewide cost blends; this /line/auto page measures company-level complaint indexes. The two tables share a line label, not a shared numerator.
Group written-premium ranks from the retained NAIC market-share release: size context separate from the company complaint-index table. Top five groups: 63.5%. Full market-share research →
| # | Group | Market share |
|---|---|---|
| 1 | State Farm Group | 18.85% |
| 2 | Progressive Group | 16.70% |
| 3 | Berkshire Hathaway Group | 11.62% |
| 4 | Allstate Insurance Group | 10.18% |
| 5 | United Services Automobile Association Group | 6.16% |
| 6 | Farmers Insurance Group | 3.75% |
| 7 | Liberty Mutual Group | 3.27% |
| 8 | Travelers Group | 2.00% |
Spread: index 0.34–3.87 · IQR 1.54 · 14/21 above 1.0.
| # | Insurer | Grade | Complaint index | States |
|---|---|---|---|---|
| 1 | Gainsco Insurance Gainsco | F | 3.87 +287% vs. avg
| 7 |
| 2 | Infinity P&C (Kemper) Kemper | F | 3.01 +201% vs. avg
| 13 |
| 3 | Root Insurance Root | F | 2.97 +197% vs. avg
| 34 |
| 4 | SafeAuto (Kemper) Kemper | F | 2.87 +187% vs. avg
| 17 |
| 5 | Direct General (Allstate) Allstate | F | 2.56 +156% vs. avg
| 26 |
| 6 | Kemper Auto Kemper | F | 2.43 +143% vs. avg
| 45 |
| 7 | Dairyland Insurance (Sentry) Sentry | F | 2.34 +134% vs. avg
| 40 |
| 8 | Esurance (Allstate) Allstate | F | 1.98 +98% vs. avg
| 41 |
| 9 | Mercury Insurance Mercury General | D | 1.78 +78% vs. avg
| 11 |
| 10 | Farmers Insurance Zurich | D | 1.56 +56% vs. avg
| 42 |
| 11 | GEICO Berkshire Hathaway | D | 1.43 +43% vs. avg
| 50 |
| 12 | Liberty Mutual Liberty Mutual | C | 1.34 +34% vs. avg
| 50 |
| 13 | Allstate Insurance Allstate | C | 1.21 +21% vs. avg
| 49 |
| 14 | The Hartford Auto Hartford Financial | C | 1.05 +5% vs. avg
| 50 |
| 15 | Nationwide Insurance Nationwide | C | 0.98 -2% vs. avg
| 50 |
| 16 | Progressive Insurance Progressive | C | 0.89 -11% vs. avg
| 50 |
| 17 | Travelers Insurance Travelers | B | 0.87 -13% vs. avg
| 50 |
| 18 | American Family Insurance American Family | B | 0.76 -24% vs. avg
| 19 |
| 19 | State Farm State Farm | B | 0.67 -33% vs. avg
| 50 |
| 20 | Erie Insurance Erie Indemnity | A | 0.52 -48% vs. avg
| 12 |
| 21 | USAA USAA | A | 0.34 -66% vs. avg
| 50 |
Data: NAIC MCAS 2026. Sorted by average complaint ratio (highest first).
Among the 21 auto insurance carriers PlainInsurer tracks with a ratio, Gainsco Insurance posts the highest index (3.87; line median 1.43). The index normalizes complaints by premium share; it is not a claim-denial rate.
USAA posts the lowest index among tracked auto insurance carriers (0.34 vs median 1.43). A low index means fewer regulator-confirmed complaints relative to premium volume in the MCAS extract, not a price or coverage rating.
In the 2024 market-share release, the five largest groups account for 63.5% of written premium; the largest named group is State Farm Group at 18.9%. Group premium share and company complaint index use different NAIC extracts.
Read our methodology - how this data is sourced, computed, and verified.