Short answer

Cannabis stays in Schedule I of the federal Controlled Substances Act. THC is Schedule I. States set their own rules, and two dozen states plus the District of Columbia allow adult use, but no state law overrides federal law. Hemp with 0.3% or less delta-9 THC on a dry weight basis is legal under the 2018 Farm Bill.

does federal law prevent state legalization

The Controlled Substances Act

Congress placed cannabis and tetrahydrocannabinol in Schedule I at 21 U.S.C. § 812. Schedule I is reserved for drugs with a high potential for abuse and no accepted medical use in treatment in the United States. Heroin and LSD sit in the same schedule.

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The CSA covers the plant, THC, and other cannabinoids. Simple possession of a small amount carries up to 1 year in prison and a $1,000 minimum fine for a first offense under 21 U.S.C. § 844. Trafficking penalties scale with weight.

does federal law prevent state legalization

Research runs through DEA registration. The National Institute on Drug Abuse contracts with the University of Mississippi to grow cannabis for FDA-authorized studies.

is cannabis illegal federally in the us

Hemp and the 0.3% line

The 2018 Farm Bill removed hemp from the CSA definition of marijuana. Hemp is Cannabis sativa L. and any part of the plant with a delta-9 THC concentration of 0.3% or less on a dry weight basis. The USDA oversees state, tribal, and federal hemp production plans.

Material above 0.3% delta-9 THC remains Schedule I. That line covers most dispensary flower, edibles, and vapes sold as high-THC products.

FDA position

The FDA has not approved cannabis for any medical use. It has approved one CBD drug, Epidiolex, for rare seizure disorders, and two synthetic THC drugs, dronabinol and nabilone, for nausea and appetite loss. Those drugs sit below Schedule I. The FDA has flagged risks from CBD, including liver injury.

State law versus federal law

State licenses shield businesses from state prosecution. They do not shield against federal charges, federal tax rules, or banking limits. Moving cannabis across state lines is a federal crime even when both states allow sales.

IRS Section 280E bars deductions and credits for businesses that traffic in Schedule I or Schedule II drugs. Cannabis companies pay tax on gross income.

Congress has renewed an appropriations rider since 2014 that blocks the Justice Department from spending funds to stop states from running medical cannabis programs. Adult-use programs get no such protection.

The Cole Memo of 2013 listed federal enforcement priorities. Attorney General Jeff Sessions withdrew it in January 2018.

Rescheduling

In August 2023, the Department of Health and Human Services recommended moving cannabis to Schedule III. In May 2024, the DEA published a proposed rule to do that. The rule is not final. DEA has not issued a final rule, and cannabis remains Schedule I until one takes effect.

Schedule III would not legalize cannabis. It would end the 280E tax limit and ease some research barriers. Trafficking would stay criminal, with lower penalties.

Federal bills

Congress has not passed a legalization bill. The MORE Act passed the House in 2020 and 2022 and got no Senate vote. Federal legalization stays a proposal.

What this means for buyers