2018 Farm Bill

The Agriculture Improvement Act of 2018 (Pub. L. 115-334), signed December 20, 2018, removed hemp from the CSA definition of marihuana and created a federal regulatory framework for hemp cultivation. The bill defined hemp at 7 U.S.C. § 1639o as "the plant Cannabis sativa L. and any part of that plant, including the seeds thereof and all derivatives, extracts, cannabinoids, isomers, acids, salts, and salts of isomers … with a delta-9 tetrahydrocannabinol concentration of not more than 0.3 percent on a dry weight basis." USDA was designated the primary regulator for cultivation, with state and tribal plans submitted for approval, and FDA retained jurisdiction over hemp-derived ingestibles. The bill's narrow "delta-9 only" threshold created the so-called "hemp loophole" that spawned the multibillion-dollar intoxicating-hemp market (delta-8 THC, THCA flower, HHC, THC-O). That loophole was substantially closed by P.L. 119-37, Division B (signed Nov. 12, 2025), which redefined hemp by total THC and caps consumer products at 0.4 mg total THC per container; the new definition takes effect November 12, 2026. → See also: Hemp, 0.3% threshold; USDA