Is THCA Legal in Wisconsin? What State Law Says in 2026

THCA in Wisconsin at a glance

Status	Unclear
Age limit	None set in state law
Sale	No law specifically licenses or bans THCA sales, but products testing above 0.3% delta-9 THC after decarboxylation fall outside the hemp definition.
Possession	Cannabis above the hemp limit is a Schedule I substance, and Wisconsin has no adult-use or medical cannabis programme.
Product rules	Hemp must test at no more than 0.3% delta-9 THC on a dry weight basis using post-decarboxylation or a similarly reliable method; no other state product limits found.
Licensing	No Wisconsin licence is required specifically to sell hemp products, and there is no licensed cannabis market.
Key law	Wis. Stat. § 94.55(1); Wis. Stat. § 961.14(4)(t)

What Wisconsin law says about THCA

Wisconsin’s hemp statute, Wis. Stat. § 94.55, defines hemp as cannabis with a delta-9 THC concentration of no more than 0.3% on a dry weight basis (or any higher federal limit up to 1%), as tested using post-decarboxylation or other similarly reliable methods. Decarboxylation converts THCA into delta-9 THC, so this wording effectively measures THCA as well.¹

Wisconsin’s controlled substances schedule covers tetrahydrocannabinols in any form, excluding only THC contained in hemp as defined in § 94.55. A product that fails the post-decarboxylation test is therefore not hemp and would fall under the drug laws. Wisconsin has no adult-use or medical cannabis programme, so there is no licensed route for high-THC flower.²

No state agency guidance or court ruling applying the testing language to retail THCA products was found, and Wisconsin has no retail licensing system that tests hemp products at the point of sale. Bills in the 2025 to 2026 session to redefine hemp and regulate hemp-derived cannabinoid products all failed on 23 March 2026. The federal total THC definition due on 11 December 2026 adds further pressure on THCA flower.³⁴

Pending changes to watch

None in the legislature: the 2025 to 2026 hemp bills (AB 503/SB 499, AB 680/SB 644 and AB 747/SB 682) failed on 23 March 2026. New proposals could be introduced when the next legislature convenes in January 2027.

How the federal hemp change affects Wisconsin

Separate from Wisconsin law, the federal definition of hemp is changing. Under the federal hemp redefinition passed in the FY2026 appropriations law, from 11 December 2026 hemp is measured by total THC, which counts THCA as well as delta-9 THC, and finished products are capped at 0.4 mg of total THC per container. High-THCA flower sold as hemp today will not meet that definition, so from that date it is treated as marijuana under federal law, whatever state law says.

Bills to delay or repeal the change are in congressional committees, but none had advanced as of September 2026. Our explainer on the federal hemp THC limit covers the detail, and THCA vs delta-9 THC explains why heat turns THCA into delta-9.

Timeline of recent changes

• 23 March 2026: 2025 to 2026 bills to redefine hemp and regulate hemp-derived cannabinoid products failed as the session ended.

THCA in neighbouring states

Rules change at the state line. Here is how THCA is treated in the states bordering Wisconsin, as of September 2026:

• Minnesota: Cannabis retailers only, 21+
• Iowa: THCA flower and vapes banned
• Illinois: 21+; hemp sales end 12 Nov 2026
• Michigan: Licensed marijuana stores only, 21+

Carrying products across state lines can break the law of the state you enter, and federal law also applies. Check the destination state’s rules first.

Delta-8 in Wisconsin

Delta-8 is treated differently: in Wisconsin it is Legal, largely unregulated as of September 2026. Read our guide to Delta-8 law in Wisconsin, or compare the two compounds in THCA vs Delta-8.

Frequently asked questions

Is THCA flower legal in Wisconsin?

It is legally uncertain. Wisconsin’s hemp definition requires delta-9 THC to be tested after decarboxylation, which converts THCA into THC, so most THCA flower would exceed 0.3% and not count as hemp. However, no state guidance or court ruling has applied this to retail THCA products, and there is no state licensing system for them.

Does Wisconsin count THCA in hemp testing?

The statute points that way. Wis. Stat. § 94.55 defines hemp by a delta-9 THC limit as tested using post-decarboxylation or other similarly reliable methods. Post-decarboxylation testing turns THCA into delta-9 THC, so the result reflects the combined total rather than delta-9 alone.

Is there an age limit for THCA in Wisconsin?

Not in state law. Bills in the 2025 to 2026 session would have banned sales of intoxicating hemp products to people under 21, but they failed on 23 March 2026. Wisconsin also has no adult-use or medical cannabis programme, so there is no licensed cannabis market with its own age rules.

Sources

1. Wisconsin Legislature. Wis. Stat. § 94.55, Hemp (2025 to 2026 statutes). docs.legis.wisconsin.gov
2. Wisconsin Legislature. Wis. Stat. § 961.14(4)(t), Schedule I tetrahydrocannabinols and hemp exclusion. docs.legis.wisconsin.gov
3. Wisconsin Legislature. 2025 Assembly Bill 503 (“hemp” definition changed; hemp-derived cannabinoid product defined), failed to pass 23 March 2026. docs.legis.wisconsin.gov
4. Wisconsin Legislature. 2025 Assembly Bill 747 (hemp-derived cannabinoid products; sales rules; under-21 ban), failed to pass 23 March 2026. docs.legis.wisconsin.gov

Editorial note: This page is general legal information, not legal advice, and reflects our reading of Wisconsin and federal law as of 24 September 2026. Hemp and cannabis laws change quickly and are enforced differently by different agencies and localities. If you sell, ship or carry these products, check the current rules with the relevant state agency or a licensed attorney.

See the full state-by-state THCA table →