The "Stop the Opioid Pill Presser and Fentanyl Act," or STOPP Act, significantly amends the Controlled Substances Act by extending regulatory oversight beyond just tableting and encapsulating machines to also include their critical parts . This measure is designed to combat the illicit manufacture of controlled substances, especially fentanyl, by making it more difficult for unauthorized individuals to acquire and utilize the necessary equipment. The bill specifically defines various components as "critical parts," such as press punches, die systems, and hoppers, while also granting the Attorney General authority to designate additional items through regulation. Under this legislation, transactions involving these machines and their critical parts will be subject to more stringent record-keeping and reporting requirements to the Attorney General. A key provision introduces mandatory serialization , requiring each machine and critical part to have a permanently affixed serial number for identification. Manufacturers, distributors, importers, and exporters are obligated to report these serialized items and their associated transactions. The bill establishes a comprehensive registration system for these machines and critical parts, which will be maintained in a "National Pill Press Registry" by the Attorney General. Furthermore, businesses engaged in the manufacture, import, export, or dealing of these items must obtain an annual registration from the Attorney General. This registration can be denied, suspended, or revoked if inconsistent with public interest, considering factors like diversion control, legal compliance, and prior convictions. Finally, the STOPP Act creates new offenses and penalties for non-compliance with the serialization and registration requirements. It explicitly prohibits the intentional removal, alteration, or obliteration of serial numbers, as well as the possession of machines or parts with altered serial numbers. An affirmative defense is provided for existing machines if they are properly serialized, sold to a registered entity, or destroyed within a specified grace period.