Hemp vs. marijuana: the legal line, and where it moves on Dec. 11
Hemp and marijuana are the same species. Federal law divides them by one lab figure, and on Dec. 11 it changes which figure counts. The statutes, side by side, as of Oct. 3.
The short answer. Hemp and marijuana are the same plant, Cannabis sativa L.; federal law separates them by THC content. As of Oct. 3, 2026, the plant is hemp if its delta-9 THC is no more than 0.3 percent of dry weight (7 U.S.C. 1639o), and marijuana if it is higher. On Dec. 11, 2026, the 0.3 percent limit starts counting THCA too, which moves most THCA flower to the marijuana side.
There is no botanical line between the two. A hemp field and a marijuana grow can hold plants that look, smell and smoke alike. The difference is a lab number, and Congress decides which number.
The two definitions, quoted
The Controlled Substances Act defines marijuana broadly as “all parts of the plant Cannabis sativa L., whether growing or not,” with its seeds, resin and every derivative, then carves hemp out of it: the term “does not include hemp, as defined in section 1639o of title 7” (21 U.S.C. 802(16)). So hemp is whatever the farm statute says it is, and marijuana is everything else.
Since the 2018 Farm Bill, that farm statute has read:
“the plant Cannabis sativa L. and any part of that plant … with a delta-9 tetrahydrocannabinol concentration of not more than 0.3 percent on a dry weight basis.”
Section 781 of Public Law 119-37, signed Nov. 12, 2025, replaces it with:
“the plant Cannabis sativa L. and any part of that plant … with a total tetrahydrocannabinols concentration (including tetrahydrocannabinolic acid) of not more than 0.3 percent on a dry weight basis.”
H.R. 6500 set Dec. 11, 2026, as the date the new text reaches THCA flower.
What changes on Dec. 11, test by test
| Test | Through Dec. 10, 2026 | From Dec. 11, 2026 |
|---|---|---|
| THC figure that counts | Delta-9 THC only | Total THC, including THCA |
| Limit | 0.3% of dry weight | 0.3% of dry weight |
| Per-container cap on final products | None | 0.4 mg total THC, plus THC-like cannabinoids, per container |
| Cannabinoids the plant cannot make | Not addressed | Excluded from hemp (from Nov. 12) |
| Plant cannabinoids made outside the plant, such as delta-8 from CBD | Not addressed | Excluded from hemp |
| New category | None | “Industrial hemp”: stalk, fiber, grain, seed oil, microgreens, research plants |
The industrial hemp definition is new. It covers hemp grown for fiber, grain, seed oil, microgreens and edible leaf from compliant seed, or research at a university or independent research institute, and it sits outside the “hemp-derived cannabinoid product” rules. Fiber and grain farmers are not the target of the change.
How common products fall on each side
| Product | Federal status through Dec. 10 | From Dec. 11 |
|---|---|---|
| Fiber, grain and seed-oil hemp | Hemp | Hemp (industrial hemp) |
| CBD flower at or under 0.3% total THC | Hemp | Hemp by definition; whether a bag of flower is a “final hemp-derived cannabinoid product” under the 0.4 mg cap awaits FDA guidance |
| THCA flower: under 0.3% delta-9, well over 0.3% total THC | Hemp | Marijuana, Schedule I |
| Marijuana sold in licensed adult-use stores | Marijuana, Schedule I (legal under state law) | Unchanged |
| State-licensed medical marijuana | Schedule III since April 28, 2026 | Unchanged |
The cap question is not idle. One gram of flower at exactly 0.3 percent total THC holds 3 milligrams of total THC, seven and a half times 0.4 mg. Our hemp ban tracker follows the FDA’s overdue guidance on what counts as a container.
Why THCA flower sat on the line
THCA is the acid form of THC that the living plant makes. Heat turns it into delta-9 THC, which is why labs and the USDA calculate total THC as delta-9 plus 0.877 times THCA (7 CFR 990.1). Hemp growers have been tested on total THC under USDA rules since 2021, but the statute that defines the finished product counted only delta-9. Flower that passed a delta-9 test could be sold as hemp even when its total THC matched dispensary flower. Our THCA vs. THC explainer walks through the arithmetic.
Section 781 closes that gap by writing THCA into the definition itself. The House farm bill, H.R. 7567, would also write total THC into the state and tribal grower plans; see our farm bill tracker.
Hemp vs. weed under state law
Federal law sets a floor, not a ceiling. Many states already use total THC, ban smokable hemp, or restrict THCA flower to licensed cannabis stores, so “hemp flower” can be lawful federally and unlawful at the state line. States also run a second, separate lane: licensed adult-use and medical marijuana, legal under state law whatever the federal schedule. Our legality hub sorts all 50 states and D.C. by both lanes.
Rescheduling is a different question
The April 2026 order placing FDA-approved drugs and state-licensed medical marijuana in Schedule III (91 FR 22714) states that it “does not affect the status of hemp,” because hemp is outside the definition of marijuana. Schedule III is still controlled. Our rescheduling report covers where the broader proposal stands.
Sources
- 7 U.S.C. 1639o, current hemp definition
- P.L. 119-37, sec. 781, new hemp, industrial hemp and container definitions
- 21 U.S.C. 802(16), definition of marijuana
- 7 CFR 990.1, USDA total THC definition
Last reviewed Oct. 3, 2026. This is reporting, not legal advice.
Questions readers asked
What is the difference between hemp and marijuana?
Legally, a THC number. Both are Cannabis sativa L. As of Oct. 3, 2026, federal law calls the plant hemp if its delta-9 THC is no more than 0.3 percent by dry weight and marijuana if it is higher. From Dec. 11, 2026, the 0.3 percent limit applies to total THC, including THCA.
Is hemp flower legal?
Under federal law, flower at or under 0.3 percent delta-9 THC is hemp until Dec. 11, 2026, and flower at or under 0.3 percent total THC remains hemp after that date. State law can be stricter, and many states ban smokable or high-THCA hemp flower.
Will THCA flower still be hemp after Dec. 11?
Almost never. Flower sold as THCA flower usually tests far above 0.3 percent total THC once THCA is counted, so from Dec. 11, 2026, it meets the federal definition of marijuana.
Did rescheduling make marijuana the same as hemp?
No. The April 2026 order moved FDA-approved drugs and state-licensed medical marijuana to Schedule III, which is still a controlled-substance schedule. Hemp is outside the Controlled Substances Act entirely, and the order says it does not affect hemp's status.
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