Schedule I

Schedule I is the most restrictive classification under the US Controlled Substances Act, reserved for substances deemed to have high abuse potential and no accepted medical use. Marijuana (cannabis containing >0.3% Delta-9 THC) remains Schedule I. Hemp was removed from Schedule I by the 2018 Farm Bill, making hemp-derived cannabinoids federally legal.

Example: Marijuana's Schedule I status is the central reason for the hemp/marijuana legal split.

Etymology: Statutory term from the 1970 Controlled Substances Act.