Data · California · Inland marine · Calendar year 2025
California inland marine insurance market share (2025)
Which insurance groups write the most inland marine premium in California, from the California Department of Insurance’s 2025 market share report, with each group’s 2024 share for comparison.
Key figures
- Licensed insurers wrote $3.05 billion of inland marine direct premium in California in 2025, up 2.3% from $2.98 billion in 2024. 106 groups and unaffiliated insurers wrote premium in this line.
- The ten largest groups wrote 61.08% of it (61.48% for the ten largest in 2024); the five largest wrote 44.76%.
- Liberty Mutual Group was the largest group in both years, with 14.43% of premium in 2025 (14.73% in 2024).
- Among this year’s top ten, the largest share gain from 2024 was AEGIS Group (3.41% → 4.40%, +0.99 pp), followed by Allianz Insurance Group (9.93% → 10.38%, +0.45 pp). The largest decline was CNA Insurance Group (10.50% → 9.01%, −1.49 pp), followed by Liberty Mutual Group (14.73% → 14.43%, −0.30 pp).
- The same ten groups made up the top ten in 2024.
- Of the ten, 9 are groups with more than one company writing inland marine in California; Chubb Limited Group has the most, 12. AEGIS Group has a single company writing it.
What these figures are not. Written premium is dollars, not policies or insured businesses, and the report does not count either. Market share is a share of premium written by licensed insurers; it says nothing about which groups appoint independent agencies, what they will write, or at what price.
Top 10 inland marine insurance groups, 2025
| Rank | Group | Companies | 2025 $M | 2025 share | 2024 share | Change |
|---|---|---|---|---|---|---|
| 1 | Liberty Mutual Group | 11 | 440.1 | 14.43% | 14.73% | −0.30 pp |
| 2 | Allianz Insurance Group | 5 | 316.4 | 10.38% | 9.93% | +0.45 pp |
| 3 | CNA Insurance Group | 5 | 274.8 | 9.01% | 10.50% | −1.49 pp |
| 4 | Zurich Insurance Group | 5 | 199.3 | 6.54% | 6.41% | +0.13 pp |
| 5 | AEGIS Group | 1 | 134.2 | 4.40% | 3.41% | +0.99 pp |
| 6 | Chubb Limited Group | 12 | 119.9 | 3.93% | 3.74% | +0.19 pp |
| 7 | American International Group | 4 | 115.2 | 3.78% | 3.92% | −0.14 pp |
| 8 | Assurant Group | 3 | 106.2 | 3.48% | 3.65% | −0.17 pp |
| 9 | Travelers Group | 5 | 85.7 | 2.81% | 2.89% | −0.08 pp |
| 10 | FM Group | 2 | 70.7 | 2.32% | 2.31% | +0.01 pp |
| Top 10 combined | 1,862.5 | 61.08% | ||||
| All 106 groups and unaffiliated insurers | 3,049.2 | 100.00% |
Change is in percentage points, 2024 to 2025. Each group is compared with the same group code in the department’s 2024 report.
Pet insurance is not included. The department reports Line 09 as inland marine (Line 09.1) and pet insurance plans (Line 09.2). This page covers inland marine only; pet insurance plans added $1.1 billion of direct written premium in 2025 ($0.9 billion in 2024).
What this means for commercial lines agencies
A group is not a single carrier. The Companies column counts the insurers in each group that wrote inland marine premium in California in 2025. Appointments, commission schedules and commission statements usually run per company, so one group can mean several statements to check.
Inland marine is often written as a coverage part of a commercial package policy or as equipment and builders’ risk policies whose values change during the term, so commission arrives as endorsement lines as well as at issue; commission on mid-term endorsements walks through the arithmetic.
What Lapidar checks on a commercial book, and what it does not: Lapidar for commercial lines agencies.
Methodology
- Line. Line 09.1, inland marine. Pet insurance plans (Line 09.2) are a separate line in the report and are not included. The department does not split commercial from personal inland marine.
- Measure. Direct written premium of licensed (admitted) insurers in California, before reinsurance, from the department’s insurer detail file. Surplus lines insurers are not in the report.
- Groups. Insurers are grouped under the group code the department assigns in its detail file; we do not group insurers ourselves. An insurer outside any group appears on its own. Group names are shown in plain form; the department’s abbreviated name is in each row’s tooltip.
- Checks. The 2025 and 2024 market totals match the department’s premium distribution reports for those years to the dollar. 6 of the ten have their own page in the department’s Top 25 groups report; for 4 of them the inland marine premium there matches the detail file to the dollar, and for CNA Insurance Group it differs by $2,374 and Zurich Insurance Group it differs by $1,925. We use the detail file, whose total matches the department’s premium distribution report. Shares are our calculation, rounded to 0.01 percentage point.
- Change vs 2024. Uses the same group code in the department’s 2024 report (revised September 2025). If insurers moved between groups, the change reflects that, not only new or lost business.
- What we don’t reproduce. Only the top ten. Loss data, insurer-level detail and the full report are on the department’s site.
Sources
- California Department of Insurance, Rate Specialist Bureau, 2025 California Property & Casualty Market Share Report: detail file MktShrDataPC2025.xlsx (sheet “All Individual Lines”), PrmLssDist2025.pdf and Top25grps2025.pdf. Retrieved October 14, 2026.
- 2024 figures: the department’s 2024 report, detail file MktShrDataPC2024RevSep0825.xlsx and PrmLssDist2024.pdf.
The department’s site policy treats its content as public domain unless otherwise indicated. The report notes “Source: NAIC Database”; we publish only factual figures from the department’s report, with citation. Lapidar is not affiliated with the California Department of Insurance. Check the source before relying on a figure.