Creates new law by adding two sections to chapters 48.18 and 48.19 RCW that require insurers who use a wildfire risk score to disclose that score and related information to applicants, insureds, and the insurance producer. Disclosures must include the property's current wildfire risk score, the model's possible score range, the model creator, the score date, key adverse factors and steps to improve the score, and must be provided in writing in plain language no later than 15 days after a coverage acceptance or decline. The same information must be included in renewal, nonrenewal, or cancellation notices, and insurers must post on their public website details about available mitigation-related discounts and the appeal process. Imposes procedural and filing requirements for insurers and the Office of the Insurance Commissioner. Insurers must submit the wildfire risk model or scoring method, model description, impact on rates, actuarial justification for rating factors and mitigation discounts, and an explanation of how models account for statewide and local mitigation activities as part of their complete rate filings. Models and all attributes used to calculate scores must be filed with the commissioner before use and are confidential, treated as trade secrets under RCW 48.02.120(3). Insurers must ensure models demonstrably include property-specific and community-level mitigation actions or provide discounts to policyholders who show such mitigation; insurers must provide a revised score within 30 calendar days after receiving documentation of mitigation. The bill establishes an appeal procedure to the insurer (acknowledge receipt within 10 calendar days and issue a written decision within 30 calendar days) and allows the commissioner to adopt implementing rules. Defines key terms used in the new sections, including "insurer," "wildfire risk score," "catastrophe model," "community-level mitigation action," "property-specific mitigation action," and "wildfire risk model," and identifies affected parties (the Office of the Insurance Commissioner, authorized insurers, insurance producers, applicants, policyholders, property owners, and community entities). The text references other RCW provisions (RCW 48.18.2901, RCW 48.18.290, RCW 48.19.040(5), and RCW 48.02.120(3)) but does not include their text; the bill directs the commissioner to adopt rules "as necessary" without specifying those rules or timelines, and it does not define "complete rate filing" within the provided text.

If enacted, insurers writing home coverage in Washington will have to tell applicants, policyholders, and their agents the property's wildfire risk score, how the score was made, what drove a high score, and how to lower it; they must do this quickly after an application decision and include the same information on renewals or cancelation notices. Companies will also need a process to re-score homes within about a month after receiving proof of mitigation, handle appeals with set short deadlines, post available mitigation discounts and appeal steps on their websites, and either build mitigation into their pricing models or give discounts when customers demonstrate mitigation. Practically, that means insurers will face new ongoing administrative work, disclosure duties, potential lost premium income from discounts, and filing obligations to the state insurance office, while homeowners and agents gain clearer information, a way to challenge scores, and more concrete options to lower costs by doing verified mitigation. Key implementation details remain unclear from the text provided: the exact timing and format required for "complete rate filings," how the commissioner will write rules and when, and how referenced notice and filing statutes interact with these duties. The bill also protects model filings as trade secrets except for enforcement uses, so regulators will get the technical materials even if the public will not.