Is THCA legal? The federal hemp rule and the December change

The 2018 farm bill defined hemp as cannabis with a delta-9 THC concentration of not more than 0.3% on a dry weight basis, and removed hemp from the federal definition of marijuana. THCA is not delta-9 THC until it is heated; our guide to THCA vs THC explains the chemistry.

That gap is the basis for products sold as hemp that are high in THCA. The Congressional Research Service describes it carefully: "Some have interpreted the 2018 farm bill definition to mean that products containing 0.3% delta-9 THC or less, and that may contain significant amounts of other psychoactive compounds, would not be considered marijuana and would legally be considered hemp." It adds that this reading is known as the farm bill loophole.

Congressional Research Service ↗

"Some have interpreted" is the important phrase. It is a reading of the statute, not a ruling that every THCA product is lawful.

Congress rewrote the definition in November 2025. Under the new text, hemp is cannabis "with a total [THC] concentration (including tetrahydrocannabinolic acid [THCA]) of not more than 0.3 percent on a dry weight basis."

Congressional Research Service ↗

Counting THCA closes the gap described above. Products that fall outside the new definition "are not to be deemed hemp products and would instead be subject to regulation under the CSA as marijuana," the Controlled Substances Act. The new definition also excludes final hemp-derived products with more than 0.4 milligrams of total THC per container.

Date	What happened or happens
2018	The farm bill defines hemp by delta-9 THC only (0.3% or less)
November 12, 2025	Congress enacts a new definition based on total THC, to start one year later
September 2026	Congress delays most of the new definition to December 11, 2026
November 12, 2026	One part starts on time: products with cannabinoids the plant cannot naturally produce, such as THC-O, are no longer hemp
December 11, 2026	The rest starts: total THC including THCA, and the 0.4 mg per container limit

Checked on November 12, 2026, against two Congressional Research Service reports. CRS Legal Sidebar LSB11496 This may move again: the same report lists bills in Congress that would delay the new definition by two more years (H.R. 7010, H.R. 7024 and S. 3686) or repeal it (H.R. 6209). None had become law when the report was published on October 28, 2026.

That is not known. A Congressional Research Service analysis says "it remains unclear if and how federal law enforcement will enforce the new prohibitions when the new definition goes into effect," and notes that the federal response to state marijuana programs has largely been to let states implement their own laws.

Congressional Research Service ↗

Unclear enforcement is not the same as legal. The definition changes what the product is under federal law whether or not anyone acts on it.

Federal law is only half the answer. States write their own hemp and cannabis rules, and a product that qualifies as hemp federally can still be restricted where you live. This guide covers the federal rule only; it does not rank states, because the rules differ and change.

Start with your state's page in our state-by-state law guide. In states with licensed dispensaries, THCA flower sold there is regulated cannabis, tested and labeled under state rules; see THC, total THC and potency labels.

Is THCA flower legal?

Under one reading of the 2018 federal definition, flower with 0.3% delta-9 THC or less counts as hemp even if it is high in THCA. From December 11, 2026 the federal test counts THCA, and state law can already be stricter.

Is THCA being banned?

The federal definition of hemp changes on December 11, 2026 to count THCA toward the 0.3% limit. Products over the limit would be treated as marijuana under federal law. Bills to delay or repeal the change were pending in October 2026.

Is THCA legal in Texas, Florida or Tennessee?

Each state sets its own hemp rules, and this guide does not cover them one by one. Check your state's page in our law guide and the state regulator it links to.

Is THCA the same as weed?

THCA is the form of THC the cannabis plant makes, and heat turns it into THC. Whether a THCA product is legally hemp or marijuana depends on the definition in force and on state law.

Does the 0.4 mg limit apply to THCA products?

From December 11, 2026, final hemp-derived products with more than 0.4 milligrams of total THC per container are excluded from the federal definition of hemp, and total THC includes THCA.