Cannabis is legal for some uses in many US states and illegal under federal law. The answer depends on three things: where you are, what form the product takes, and who sells it.
Federal law
Cannabis with more than 0.3% THC by dry weight sits on Schedule I of the Controlled Substances Act (21 U.S.C. 812). Schedule I means the DEA treats the plant as having no accepted medical use and high abuse potential. Possession, cultivation, and sale remain federal offenses outside narrow research programs. DEA proposed a move to Schedule III in 2024. That rule is still in process. Check the DEA docket for the status before you rely on it.
The hemp exception
The Agriculture Improvement Act of 2018 (7 U.S.C. 1639o) removed hemp from the CSA definition of marijuana. Hemp is Cannabis sativa L. with 0.3% THC or less on a dry weight basis. CBD from hemp is legal under federal law. CBD from cannabis above 0.3% THC is not. That 0.3% line is why most CBD sold online comes from hemp.
FDA position on CBD
The FDA has not approved CBD as a food additive or a dietary supplement. The agency approved one CBD drug, Epidiolex, for two rare seizure disorders. FDA says it needs a rulemaking path before CBD enters foods and supplements. Many states allow CBD retail sales in the meantime.
State rules
State law falls into three groups:
- Adult use: 24 states and DC allow cannabis for adults 21 and over. Retail licensing lags in some of them.
- Medical only: about 40 states run a medical program of some kind, including most adult-use states.
- Prohibited: a smaller set of states allows no cannabis beyond low-THC CBD products.
Counts change each election cycle. Check your state health department and a current map before you buy or carry.
What changes across state lines
- Possession limits, set in grams and ounces.
- THC caps on concentrates and edibles.
- Home grow rules.
- Taxes and license types.
- CBD rules: some states require a permit or limit sales to minors.
- Driving limits. No state allows impaired driving. Some set a THC per se limit, others use field sobriety tests.
Where federal law applies
National parks, federal buildings, airports, military bases, and border checkpoints follow federal law. TSA does not search bags for cannabis, but it refers finds to local police. Carrying cannabis across a state line is a federal offense even when both states allow it.
Workplace and housing
Employers set their own drug testing rules. State legalization does not create a right to use cannabis at work. Landlords can restrict use. So can federally funded housing programs. The ADA does not protect medical cannabis use.
How to check a CBD product
Read the certificate of analysis. Confirm THC content, cannabinoid profile, and screens for pesticides and heavy metals. A hemp product with a lab report at 0.3% THC or less fits the federal definition.