Kingstone Selects ZestyAI to Power California Market Entry

ZestyAI, the Risk and Decision Intelligence Platform for the insurance industry, today announced that Kingstone Companies, Inc. (“Kingstone”) has selected Z-FIRE™, its wildfire risk model, as part of Kingstone’s planned expansion into the California homeowners market. As previously disclosed, Kingstone will enter California in Q2 2026 on an excess and surplus lines (E&S) basis, applying the same disciplined, data-driven underwriting approach that has driven record financial results in New York.

As part of its California rating and underwriting framework, Kingstone has integrated ZestyAI’s Z-FIRE wildfire risk model among the tools used to evaluate wildfire exposure at the individual-property level and to support disciplined underwriting in catastrophe-exposed regions.

As part of its California strategy, Kingstone will use Z-FIRE™, ZestyAI’s AI-powered wildfire risk model, to analyze wildfire exposure at the property level and support disciplined underwriting in catastrophe-exposed regions.

Z-FIRE uses machine learning to evaluate each property’s unique characteristics, including defensible space, building materials, topography, and vegetation, to assess wildfire exposure at a granular level. This property-level insight enables Kingstone to differentiate risk within the same territory, improving rating and underwriting precision and portfolio oversight.

This property-level insight allows insurers to differentiate risk within the same territory, improving underwriting precision and portfolio oversight.

“Our California entry reflects the same disciplined, data-driven approach that has driven our results in New York,” said Sarah (Minlei) Chen, SVP, Chief Actuary and Head of Product Management. “ZestyAI’s Z-FIRE model complements our Select platform by providing the property-level wildfire intelligence we need to rate and underwrite with precision in a complex and dynamic market like California.”

“Wildfire risk is pushing the insurance industry to embrace more advanced analytics and AI-driven decision making,” said Attila Toth, Founder and CEO of ZestyAI. “With a clearer understanding of risk, insurers can make confident decisions about where they grow, how they manage exposure, and how they continue serving communities in wildfire-prone regions.”

Kingstone recently announced plans to enter the California homeowners market on an excess and surplus lines basis as part of its broader growth strategy. The move marks the insurer’s first geographic expansion outside the Northeast and reflects growing demand for insurance capacity in wildfire-exposed regions.

Z-FIRE is approved across all Western wildfire states and was the first AI-based wildfire model approved as part of a carrier rate filing in California. ZestyAI’s broader portfolio of AI risk models has secured more than 200 regulatory approvals nationwide.

Kingstone’s California strategy builds on the operational and underwriting transformation the Company has executed over the past four years. The Company’s E&S structure provides pricing flexibility to apply forward-looking wildfire models, set rates to achieve target margin requirements, and maintain strict underwriting standards including real-time accumulation management. Kingstone is maintaining a 30% quota share on its California business to manage net exposure during the initial scaling period.