Halt All Lethal Trafficking of Fentanyl Act or the HALT Fentanyl Act This bill places fentanyl-related substances as a class into schedule I of the Controlled Substances Act. A schedule I controlled substance is a drug, substance, or chemical that has a high potential for abuse; has no currently accepted medical value; and is subject to regulatory controls and administrative, civil, and criminal penalties under the Controlled Substances Act. Additionally, the bill establishes a new, alternative registration process for schedule I research that is funded by the Department of Health and Human Services or the Department of Veterans Affairs or that is conducted under an investigative new drug exemption from the Food and Drug Administration. The bill also makes several other changes to registration requirements for conducting research with controlled substances, including permitting a single registration for related research sites in certain circumstances, waiving the requirement for a new inspection in certain situations, and allowing a registered researcher to perform certain manufacturing activities with small quantities of a substance without obtaining a manufacturing registration.