This Week in Connecticut: CART Act Rules Start to Bite

While Washington argues over bills that have not been filed, Connecticut has already started switching its AI law on. Parts of the Artificial Intelligence Responsibility and Transparency (CART) Act took effect on 1 October 2026 — a few days ago, as of this writing (5 October) [1][2].

Per a National Law Review alert by the law firm Bradley Arant Boult Cummings, Gov. Ned Lamont signed Substitute Senate Bill 5 on 27 May 2026 as Public Act No. 26-15. CT Mirror calls it a 39-section bill. A companion data-privacy law, Public Act No. 26-64, also has October provisions [1][2].

The statute text itself was not opened for the research behind this draft. Numeric thresholds below come from the law-firm summary only.

What started on 1 October 2026?

According to CT Mirror and the Bradley firm alert [1][2]:

• AI subscription disclosures
• Whistleblower protections for people working on large frontier models
• New AI definitions
• AI-related layoff disclosure: employers filing WARN Act mass-layoff notices — WARN is the US federal law that requires advance notice of certain plant closings and mass layoffs — must also tell the state Labor Department whether the layoffs relate to AI or other technological change (this detail is from the law firm)

CT Mirror also notes earlier 2026 steps: a Connecticut AI Academy, a state AI working group, and adding AI and quantum computing to the economic development plan [1].

What comes next?

The phase-in continues [1][2]:

• 1 January 2027: AI companion and chatbot rules, including not-human disclosure, suicide and self-harm protocols and protections for minors. Large frontier developers must have anonymous internal reporting channels by this date (law firm).
• 1 October 2027: notice duties for automated employment-related decision technology (AEDT): plain-language disclosure, written pre-decision notice and contact details. Using an AEDT “shall not be a defense” to a discrimination complaint (law firm; CT Mirror agrees on the 2027 date).
• 1 January 2028: social media rules for minors — no algorithmic feeds without verifiable parental consent, a one-hour daily default limit and a Surgeon General warning (law firm; CT Mirror gives the same date).

Thresholds — law firm only

These numbers come from Bradley Arant Boult Cummings’ summary on National Law Review, not from a direct read of the statute [2]:

• A frontier developer trains on more than 10²⁶ operations
• A “large” frontier developer has more than $500 million in annual gross revenue
• Whistleblower retaliation carries up to $1,000 per violation
• Generative AI providers with more than one million monthly users must embed provenance data (no start date given in the summary)

Enforcement, both sources say, rests mainly with the Attorney General [1][2].

Companion privacy law

PA 26-64, per CT Mirror, covers data-broker tracking, a ban on selling genetic data, and limits on facial recognition and surveillance pricing [1].

Who said what?

Sen. James Maroney (D-Milford), lead author, told CT Mirror: “This is a start. This is not a finish; this is not a ceiling. This is the floor” [1].

Gov. Lamont and Attorney General William Tong are quoted in the law-firm alert from the signing announcement, which was not opened. Lamont: the state “can no longer wait for Washington, D.C.” [2].

What we still don’t know

• Statute text not opened. Section numbers, the provenance start date and full penalty details are unverified beyond the law-firm summary.
• CT Mirror says some employment-related changes “start in October,” but also that the AEDT framework is due by 1 October 2027. Read together with the law firm, the binding employer notice duties for automated hiring decisions appear to begin in 2027, apart from the layoff disclosure that started this month.

The Bottom Line

Connecticut’s CART Act is no longer a future bill — subscription disclosures, frontier-model whistleblower protections, definitions and AI-related WARN layoff notices are in force as of 1 October 2026. Companions, automated hiring notices and minors’ social media rules arrive in stages through 2028. Treat the 10²⁶ / $500 million / $1,000 figures as the Bradley firm’s reading until someone opens the statute.

Sources

1. CT Mirror, 28 September 2026. https://ctmirror.org/2026/09/28/artificial-intelligence-data-privacy-laws-october-ct/
2. National Law Review / Bradley Arant Boult Cummings, 30 September 2026. https://natlawreview.com/article/sb-5-preparing-connecticuts-artificial-intelligence-responsibility-and-transparency