California SB 53: Transparency in Frontier Artificial Intelligence Act
California’s law for the biggest AI model developers: publish safety frameworks, report serious incidents, protect whistleblowers. In force since 1 January 2026.
· Cal OES begins annual anonymised reports on critical safety incidents
Applies to
Developers that train frontier models (more than 10^26 operations). Extra duties for large frontier developers with more than $500 million in annual revenue.
SB 53 applies to developers that train frontier AI models, the largest general-purpose models. The biggest of them must publish how they manage catastrophic risks, every frontier developer must publish transparency reports before releasing new models, and serious safety incidents must be reported to the state.
Signed on 29 September 2025, it took effect on 1 January 2026. The Attorney General enforces it, with civil penalties of up to $1 million per violation.
Key dates
Signed by Governor Newsom
Takes effect
First annual anonymised incident reports from Cal OES