The 16 & Up Social Media Act would prohibit social media platforms from allowing children under age 16 to create or maintain accounts. The bill defines covered platforms as publicly available websites and apps that enable user profiles, facilitate sharing of user-generated content, use design features to increase engagement (such as infinite scrolling, notifications, or recommendation algorithms), and use personal information for advertising or recommendations. Platforms would have 60 days after enactment to identify underage users, 180 days to notify them, and 30 days after notification to terminate their accounts and delete their personal data, though users would have 90 days to download a copy of their data. The legislation includes a 60-day appeals process allowing users to challenge age determinations, and enforcement would be handled by the Federal Trade Commission and state attorneys general as violations of unfair or deceptive practices. The bill would take effect one year after enactment and would not preempt state laws that provide greater protections to minors or laws related to contracts, torts, or product liability.