Washington SB 6120 regulates developers and deployers of high-risk AI systems — AI systems intended to autonomously make or be a substantial factor in making consequential decisions affecting consumers in areas such as employment, housing, credit, healthcare, education, insurance, and legal services. Developers must provide deployers with documentation on intended uses, known limitations, bias risks, evaluation methods, and mitigation measures before making a system available. Deployers must implement a risk management program, complete impact assessments before deployment and after significant updates, disclose AI use to affected consumers before interaction, and provide explanations for adverse decisions. The bill creates a private right of action for any person, with injunctive relief and attorneys' fees available, subject to a 45-day cure affirmative defense. It provides safe harbors for conformity with NIST AI RMF, ISO/IEC 42001, or equivalent frameworks, and exempts insurers, financial institutions subject to existing AI guidance, HIPAA-covered telemedicine providers, and federal government acquisitions (except for employment and housing decisions).