DEA Enforcement and Authority Act of 2021 This bill modifies enforcement authorities of the Drug Enforcement Administration (DEA). First, the bill modifies the required elements of an order to show cause issued by the DEA before it denies, revokes, or suspends a registration due to a violation of the Controlled Substances Act. Specifically, the bill eliminates the requirement that an order to show cause must notify the registrant of the opportunity to submit a corrective action plan. Second, the bill modifies the standard of review for an immediate suspension order. Currently, the DEA may immediately suspend the registration of a controlled substances manufacturer, distributor, or dispenser to prevent imminent danger to the public health or safety. This bill lowers the standard for determining imminent danger to the public health or safety—from substantial likelihood of an immediate threat of harm to probable cause that harm will occur.