Data · California · Private passenger auto · 2015–2025
California auto insurance market share, 2015–2025
Who writes California’s private passenger auto insurance, and how that changed over eleven years of the California Department of Insurance’s market share reports: premium by year, the 2025 top ten groups, and how concentrated the market is.
Key figures
- Private passenger auto direct written premium of licensed insurers went from $23.3 billion in 2015 to $48.4 billion in 2025 (+108.2%). It rose in 9 of the 10 year-over-year changes; the one decline was −2.6% in 2020. The largest annual increase was +19.4% in 2024.
- State Farm Group was the largest private auto writer in each of the 11 years. Its share was 14.45% in 2015, 12.06% in 2021 (its low point) and 13.83% in 2025. Second place changed hands: Farmers Insurance Group in 2015–2019; Berkshire Hathaway Group in 2020–2023; Auto Club Enterprises Insurance Group in 2024–2025.
- Among the 2025 top ten, the largest share gain from 2015 to 2025 was Auto Club Enterprises Insurance Group (8.11% → 11.74%, +3.63 pp), followed by Progressive Group (4.17% → 7.58%, +3.41 pp). The largest decline was Farmers Insurance Group (12.45% → 7.50%, −4.95 pp), followed by Mercury General Group (8.27% → 6.32%, −1.95 pp).
- The ten largest groups wrote 78.47% of private auto premium in 2015 and 84.65% in 2025; the range over the period was 78.25% (2016) to 85.40% (2021). The five largest: 52.02% in 2015 and 53.81% in 2025, within a range of 51.30% (2019) to 54.41% (2022). Each year’s figure uses that year’s top five or ten.
- Private auto top ten, 2015 vs 2025: Kemper Corporation Group joined; Liberty Mutual Group dropped out.
What these figures are not. Written premium is dollars, not policies or vehicles: premium can rise because rates rise while the number of cars insured stays flat or falls, and these reports do not count policies. Market share is a share of premium written by licensed insurers; it says nothing about whether a given driver can buy coverage from a group, at what price, or where in the state.
Private auto premium by year
Direct written premium, private passenger auto liability and physical damage (Lines 19.2 + 21.1), licensed insurers, $ billion. Axis starts at zero.
Top 10 auto insurance groups, 2025
| # | Group | 2025 $M | 2015 | 2020 | 2025 | Change | 2015–2025 |
|---|---|---|---|---|---|---|---|
| 1 | State Farm Group | 6,693 | 14.45% | 12.78% | 13.83% | −0.62 pp | |
| 2 | Auto Club Enterprises Insurance Group | 5,684 | 8.11% | 9.17% | 11.74% | +3.63 pp | |
| 3 | Berkshire Hathaway Group | 5,261 | 7.80% | 10.78% | 10.87% | +3.07 pp | |
| 4 | Allstate Insurance Group | 4,464 | 8.74% | 9.85% | 9.22% | +0.48 pp | |
| 5 | CSAA Insurance Group | 3,941 | 6.58% | 6.80% | 8.14% | +1.56 pp | |
| 6 | Progressive Group | 3,669 | 4.17% | 5.73% | 7.58% | +3.41 pp | |
| 7 | Farmers Insurance Group | 3,632 | 12.45% | 10.61% | 7.50% | −4.95 pp | |
| 8 | Mercury General Group | 3,059 | 8.27% | 7.39% | 6.32% | −1.95 pp | |
| 9 | USAA Group | 2,487 | 4.49% | 5.00% | 5.14% | +0.65 pp | |
| 10 | Kemper Corporation Group | 2,080 | 2.61% | 6.84% | 4.30% | +1.69 pp |
Change is in percentage points (2015 to 2025). Each sparkline has its own vertical scale (at least one percentage point tall), so compare slopes within a row, not heights across rows. Every year’s share for every group is in the trends data.json.
Whose share moved most
| Group | 2015 | 2025 | Change | Premium |
|---|---|---|---|---|
| Farmers Insurance Group | 12.45% | 7.50% | −4.95 pp | +25.5% |
| Auto Club Enterprises Insurance Group | 8.11% | 11.74% | +3.63 pp | +201.5% |
| Progressive Group | 4.17% | 7.58% | +3.41 pp | +278.8% |
| Berkshire Hathaway Group | 7.80% | 10.87% | +3.07 pp | +190.0% |
| Mercury General Group | 8.27% | 6.32% | −1.95 pp | +59.0% |
| Kemper Corporation Group | 2.61% | 4.30% | +1.69 pp | +242.7% |
| CSAA Insurance Group | 6.58% | 8.14% | +1.56 pp | +157.6% |
| USAA Group | 4.49% | 5.14% | +0.65 pp | +138.0% |
| State Farm Group | 14.45% | 13.83% | −0.62 pp | +99.3% |
| Allstate Insurance Group | 8.74% | 9.22% | +0.48 pp | +119.6% |
Concentration: top 5 and top 10
| Year | Total $B | vs prior yr | Top 5 share | Top 10 share | State Farm |
|---|---|---|---|---|---|
| 2015 | 23.25 | 52.02% | 78.47% | 14.45% | |
| 2016 | 25.26 | +8.6% | 51.65% | 78.25% | 14.47% |
| 2017 | 27.26 | +7.9% | 52.57% | 79.50% | 14.34% |
| 2018 | 29.89 | +9.6% | 51.80% | 82.36% | 13.74% |
| 2019 | 31.12 | +4.1% | 51.30% | 82.67% | 12.75% |
| 2020 | 30.32 | −2.6% | 53.19% | 84.95% | 12.78% |
| 2021 | 31.72 | +4.6% | 53.91% | 85.40% | 12.06% |
| 2022 | 32.70 | +3.1% | 54.41% | 84.51% | 12.39% |
| 2023 | 36.56 | +11.8% | 53.60% | 83.63% | 12.85% |
| 2024 | 43.64 | +19.4% | 54.06% | 84.98% | 13.58% |
| 2025 | 48.40 | +10.9% | 53.81% | 84.65% | 13.83% |
Methodology
- Source and years. One California Department of Insurance market share report per calendar year, 2015 through 2025 (11 years). Earlier reports are not included.
- Measure. Direct written premium of licensed (admitted) insurers on private passenger auto liability (Line 19.2) and private passenger auto physical damage (Line 21.1), combined as the department combines them, before reinsurance. Commercial auto is not included. Surplus lines insurers are not in these reports. Premium is not a count of policies, and share is not a measure of availability.
- Groups. Each year’s figures use the group codes in that year’s report. The top-ten table follows the 2025 top ten back by group code; every one of those codes appears in every year. If insurers moved between groups, earlier figures reflect the group’s make-up at the time. Top 5 and top 10 shares in the concentration table use each year’s own ranking.
- Checks. Our market total is the sum of the insurer rows in the department’s detail file. From 2017 on it matches the total stated on the department’s own private auto group sheet to the dollar; in 2015 and 2016 our sum is higher by $1,002 in 2015 and $700 in 2016 (about $1,000 in a market of more than $23 billion), and we use our sum. The top ten groups match that sheet in every year. Shares are our calculation, rounded to 0.01 percentage point.
- No causes. The reports give figures, not reasons. This page describes what changed and does not explain why.
Sources
- 2015: California Department of Insurance, Rate Specialist Bureau, 2015 California Property & Casualty Market Share Report, detail file MktShrDataPC2015WA.xlsx. Retrieved October 13, 2026.
- 2016: California Department of Insurance, Rate Specialist Bureau, 2016 California Property & Casualty Market Share Report, detail file MktShrDataPC2016WA.xlsx. Retrieved October 13, 2026.
- 2017: California Department of Insurance, Rate Specialist Bureau, 2017 California Property & Casualty Market Share Report, detail file MktShrDataPC2017WA.xlsx. Retrieved October 13, 2026.
- 2018: California Department of Insurance, Rate Specialist Bureau, 2018 California Property & Casualty Market Share Report, detail file MktShrDataPC2018WA_RevisedAug1519.xlsx. Retrieved October 13, 2026.
- 2019: California Department of Insurance, Rate Specialist Bureau, 2019 California Property & Casualty Market Share Report, detail file MktShrDataPC2019WA_Apr3020.xlsx. Retrieved October 13, 2026.
- 2020: California Department of Insurance, Rate Specialist Bureau, 2020 California Property & Casualty Market Share Report, detail file MktShrDataPC2020WA.xlsx. Retrieved October 13, 2026.
- 2021: California Department of Insurance, Rate Specialist Bureau, 2021 California Property & Casualty Market Share Report, detail file MktShrDataPC2021_Apr2922_Final.xlsx. Retrieved October 13, 2026.
- 2022: California Department of Insurance, Rate Specialist Bureau, 2022 California Property & Casualty Market Share Report, detail file MktShrDataPC2022.xlsx. Retrieved October 13, 2026.
- 2023: California Department of Insurance, Rate Specialist Bureau, 2023 California Property & Casualty Market Share Report, detail file MktShrDataPC2023wa.xlsx. Retrieved October 13, 2026.
- 2024: California Department of Insurance, Rate Specialist Bureau, 2024 California Property & Casualty Market Share Report, detail file MktShrDataPC2024RevSep0825.xlsx. Retrieved October 13, 2026.
- 2025: California Department of Insurance, Rate Specialist Bureau, 2025 California Property & Casualty Market Share Report, detail file MktShrDataPC2025.xlsx. Retrieved October 13, 2026.
The department’s site policy treats its content as public domain unless otherwise indicated. The reports note “Source: NAIC Database”; we publish only factual figures from the department’s reports, with citation. Lapidar is not affiliated with the California Department of Insurance. Check the source before relying on a figure.