---
type: source
title: "California SB 53: The Transparency in Frontier AI Act (Signed September 2025)"
author: "California Legislature; analysis via Wharton Accountable AI Lab, Future of Privacy Forum, TechPolicy Press"
url: https://ai-analytics.wharton.upenn.edu/wharton-accountable-ai-lab/sb-53-what-californias-new-ai-safety-law-means-for-developers/
date: 2025-10-00
domain: ai-alignment
secondary_domains: []
format: legislation-analysis
status: processed
priority: high
tags: [California, SB53, frontier-AI-regulation, compliance-evidence, independent-evaluation, voluntary-testing, self-reporting, Stelling-et-al, governance-architecture]
---

## Content

California SB 53 — the Transparency in Frontier AI Act — was signed by Governor Newsom on September 29, 2025. It is the direct successor to SB 1047 (the Safe and Secure Innovation for Frontier Artificial Intelligence Models Act, vetoed 2024). Effective January 1, 2026.

**Scope**: Applies to "large frontier developers" — defined as training frontier models using >10^26 FLOPs AND having $500M+ annual gross revenue (with affiliates). This covers the largest frontier labs.

**Core requirements**:
1. **Safety framework**: Must create detailed safety framework before deploying new or substantially modified frontier models
   - Must align with "recognized standards" such as NIST AI Risk Management Framework or ISO/IEC 42001
   - Must describe internal governance structures, cybersecurity protections for model weights, and incident response systems
2. **Transparency report**: Must publish before or concurrent with deployment
   - Must describe model capabilities, intended uses, limitations, and results of risk assessments
   - Must disclose "whether any third-party evaluators were used"
3. **Annual review**: Frameworks must be updated annually

**Independent evaluation**: Third-party evaluation is VOLUNTARY. The law requires disclosure of whether third-party evaluators were used — not a mandate to use them. Language: transparency reports must include "results of risk assessments, including whether any third-party evaluators were used."

**Enforcement**: Civil fines up to $1 million per violation.

**Catastrophic risk definition**: Incidents causing injury to 50+ people OR $1 billion in damages.

**Clarification context**: Previous research sessions (2026-03-20) referenced "California's Transparency in Frontier AI Act" as relying on 8-35% safety framework quality for compliance evidence. This is that law. AB 2013 (a separate 2024 law) covers only training data transparency. SB 53 is the compliance evidence law — confirming that California's safety requirements accept self-reported safety frameworks aligned with NIST/ISO/IEC 42001.

**Comparison to Stelling et al. finding**: Stelling et al. (arXiv:2512.01166) found frontier safety frameworks score 8-35% of safety-critical industry standards. If SB 53 accepts NIST AI RMF alignment as compliance, and if labs' safety frameworks score 8-35% on the relevant standards, California's compliance architecture is substantively inadequate — exactly as Session 9 diagnosed.

## Agent Notes

**Why this matters:** This clarifies a critical ambiguity from sessions 9-10. Two different California laws were being conflated: AB 2013 (training data transparency only, no evaluation requirements) and SB 53 (safety framework + transparency reporting, effective January 2026). SB 53 IS a compliance evidence requirement — but it accepts self-reported safety frameworks, not mandatory independent evaluation. This confirms the structural diagnosis: California's frontier AI law follows the same self-reporting model as the EU Code of Practice, not the FDA model.

**What surprised me:** The $1 billion / 50 people catastrophic risk threshold is much higher than expected — it functionally excludes most AI safety scenarios that don't produce mass casualties or economic devastation as a threshold event. The definition of catastrophic may be too high to capture the alignment-relevant risks (gradual capability concentration, epistemic erosion, incremental control erosion).

**What I expected but didn't find:** I expected California to have stronger independent evaluation requirements given the SB 1047 debate. The final SB 53 is significantly weaker than SB 1047 in requiring only disclosure of third-party evaluation, not mandating it. The California civil society pressure produced a transparency law, not an independent evaluation mandate.

**KB connections:**
- Resolves: ambiguity in 2026-03-20 session about which California law Stelling et al. referred to
- Confirms: Session 9 diagnosis (substantive inadequacy — 8-35% compliance evidence quality) — SB 53 accepts the same framework quality that Stelling scored poorly
- Confirms: domains/ai-alignment/voluntary-safety-pledge-failure.md — California's mandatory law makes third-party evaluation voluntary
- Connects to: domains/ai-alignment/alignment-governance-inadequate-inversion.md (government designation as risk vs. safety)

**Extraction hints:**
1. New claim: "California SB 53 makes independent third-party AI evaluation voluntary while requiring only disclosure of whether it was used — maintaining the self-reporting architecture that Stelling et al. scored at 8-35% quality"
2. New claim: "California's catastrophic risk threshold ($1B damage or 50+ injuries) is set too high to trigger compliance obligations for most alignment-relevant failure modes"
3. Resolves ambiguity: "AB 2013 = training data transparency only; SB 53 = safety framework + voluntary evaluation disclosure; neither mandates independent pre-deployment evaluation"

## Curator Notes

PRIMARY CONNECTION: domains/ai-alignment/governance-evaluation-inadequacy claims (Sessions 8-10 arc)
WHY ARCHIVED: Definitively clarifies the California legislative picture that has been ambiguous across multiple sessions; confirms the self-reporting + voluntary evaluation architecture that Session 9 diagnosed as substantively inadequate
EXTRACTION HINT: The key claim is the contrast between what SB 53 appears to require (safety frameworks + third-party evaluation) vs. what it actually mandates (transparency reports disclosing whether you used a third party, not requiring you to)
