2018 Farm Bill

The Agriculture Improvement Act of 2018 became Public Law 115-334 on December 20, 2018 (P.L. 115-334). Two sections changed the hemp industry. Section 10113 added subtitle G to the Agricultural Marketing Act of 1946, defining hemp as Cannabis sativa L. with a delta-9 THC concentration of not more than 0.3 percent on a dry weight basis and setting up state, tribal and USDA production plans (7 U.S.C. 1639o). Section 12619 amended the Controlled Substances Act so that hemp, and THC in hemp, are no longer controlled substances.

The law did not touch FDA authority. FDA still regulates hemp-derived products under the Food, Drug, and Cosmetic Act and holds that CBD cannot lawfully be added to food or sold as a dietary supplement (FDA). USDA runs the production side through the Domestic Hemp Production Program (USDA AMS).

The 2018 definition measured only delta-9 THC. That gap allowed THCa flower and hemp-derived intoxicants to be sold as hemp. Section 781 of Public Law 119-37, enacted November 12, 2025, rewrote the definition to count total THC, exclude synthesized cannabinoids and cap finished products at 0.4 mg THC per container. The delayed parts of that rewrite take effect December 11, 2026.