H.R. 501 would expand requirements for registrants with the Drug Enforcement Administration (DEA) who manufacture, distribute, or dispense controlled substances. Under current law, those entities must register with the DEA and report suspicious orders of unusual size or frequency to the agency. H.R. 501 would require the DEA to promulgate regulations specifying what indicators registrants must use to determine whether an order is likely to be diverted and would require registrants to take additional actions in those instances, such as declining to fill orders and maintaining records of due diligence. Additionally, the bill would create new criminal and civil penalties for registrants who fail to comply with the suspicious order requirements.