The "Children Harmed by AI Technology Act 2.0" or "CHAT Act 2.0" establishes comprehensive protections for minors using companion artificial intelligence chatbots. It defines these chatbots as systems for educational purposes or simulating interpersonal interaction, friendship, or therapeutic communication, while excluding highly specialized or memory-less chatbots. The bill categorizes companion AI chatbots into three tiers: Tier I for educational use, Tier II for companionship, and Tier III for mental health or quasi-therapeutic support, with regulations tailored to each tier. All covered entities must prevent chatbots from encouraging self-harm, engaging in sexually explicit communication with minors, misleading them about being human, or fostering emotional dependency. The Act mandates an age assurance process, requiring parental contact information and activation of child-protective settings for minors, including parental controls and a system to notify parents if a minor expresses suicidal ideation. Specific requirements vary by tier: Tier I chatbots must frequently disclose their non-human identity. Tier II chatbots have more frequent disclosure and "nudge-out" notifications, must implement evidence-based crisis escalation protocols for suicidal ideation, and are generally prohibited from maintaining persistent memory of minor interactions. Tier III chatbots require professional supervision for minor use, frequent disclosures, robust crisis protocols, and are explicitly prohibited from providing diagnoses or acting as standalone mental health providers. The bill includes strong data protections, prohibiting targeted advertising to minors based on conversational content and the sale or sharing of minor user data without verifiable parental consent, and requires mechanisms for minors to delete their conversation history. Enforcement is primarily handled by the Federal Trade Commission, treating violations as unfair or deceptive acts, with State Attorneys General also authorized to bring civil actions. Additionally, the National Institute of Standards and Technology will study the impact of Tier II and Tier III chatbots on self-harm, manipulation, and exploitation, with the Act becoming effective 180 days after enactment.