This legislation directs the Government Accountability Office (GAO) to conduct a comprehensive study on the online sale of fentanyl, synthetic opioids, and methamphetamine. The study will delve into the business models employed by online sellers, including their supply chains, logistics, and strategies for customer acquisition and communication within illicit online marketplaces. Furthermore, the GAO study will investigate the utilization of online illicit drug markets for facilitating financial transactions, with a specific focus on their impact on individuals aged 18 and younger. It will also evaluate the Federal Government's efforts to combat these online sales, examining interagency, intergovernmental, and intersectoral collaboration, as well as law enforcement procedures, aggregated outcomes, and identified resource gaps. The study is also tasked with analyzing the models and enforcement mechanisms used by online providers, such as machine learning and data analysis , to detect and penalize users involved in illicit drug sales. This includes examining user identification, account suspension, and reporting to law enforcement. Finally, it will analyze referrals from providers to the Federal Government, detailing the number of referrals, investigation outcomes, arrests, prosecutions, and convictions, and how this information is shared with state, tribal, and local governments. The GAO must submit its findings and determinations to Congress within one year of the Act's enactment.