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

THCA in Montana at a glance

Status	Legal with restrictions
Age limit	21+ (licensed dispensaries only)
Sale	Only licensed marijuana dispensaries may sell THCA-rich flower and products, as marijuana.
Possession	Adults 21+ may possess marijuana, including THCA flower, within Montana's personal possession limits.
Product rules	Hemp is capped at 0.3% total delta-9 THC; consumer hemp products with total delta-9 THC are barred unless FDA-authorised, and hemp products are capped at 0.5 mg THC per serving and 2 mg per package.
Licensing	Retail sale requires a Department of Revenue marijuana dispensary licence; new licences are frozen until 30 June 2027.
Key law	MCA 80-18-101 (hemp, total delta-9 THC); MCA 50-31-239 (SB 375, 2025); MCA 16-12-117(3)-(4); Title 16, chapter 12 MCA
Last major change	5 May 2025

What Montana law says about THCA

Montana’s hemp statute defines hemp as cannabis with a total delta-9 THC concentration of no more than 0.3% on a dry-weight basis.¹ Total delta-9 THC counts the THC that THCA becomes when heated, so typical high-THCA flower is outside the hemp definition and is marijuana under state law.

SB 375, which took effect on 5 May 2025, goes further: unless authorised as a food or drug by the FDA, a hemp product containing total delta-9 THC may not be sold to a consumer in Montana. The law defines hemp products to include items intended for smoking or vaping.² MCA 16-12-117 separately caps hemp and hemp products at 0.5 mg total delta-9 THC per serving and 2 mg per package, while exempting unadulterated hemp flower from that cap. That exemption does not help high-THCA flower, which fails the hemp definition.³

Montana has legal adult-use marijuana, so THCA-rich cannabis flower is lawfully available from licensed dispensaries to adults 21 and over. Marijuana may only be sold by licensed cultivators, manufacturers and dispensaries.³ Under SB 27 (2025) the freeze on new marijuana licences runs until 30 June 2027.⁴

Local rules

Adult-use sales are only permitted in counties that voted to allow them; other counties have medical-only dispensaries.

Pending changes to watch

No bills pending: the Montana Legislature next meets in regular session in January 2027.

How the federal hemp change affects Montana

Separate from Montana 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

• 1 July 2025: SB 27 extends the moratorium on new marijuana licences to 30 June 2027.
• 5 May 2025: SB 375 bars sale to consumers of hemp products containing total delta-9 THC unless FDA-authorised.
• 7 April 2025: HB 49 caps hemp products at 0.5 mg total delta-9 THC per serving and 2 mg per package.
• 22 May 2023: HB 948 creates MCA 16-12-117, banning synthetic cannabinoid products.

THCA in neighbouring states

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

• Idaho: Illegal (treated as marijuana)
• Wyoming: Banned (post-decarb 0.3% limit)
• South Dakota: High-THCA flower illegal
• North Dakota: Banned above 0.3% total THC

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 Montana

Delta-8 is treated differently: in Montana it is Banned as a synthetic cannabinoid as of September 2026. Read our guide to Delta-8 law in Montana, or compare the two compounds in THCA vs Delta-8.

Frequently asked questions

Is THCA flower legal in Montana?

Only as marijuana. Montana measures hemp by total delta-9 THC, which includes THCA once converted, so high-THCA flower is marijuana under state law. Adults 21 and over can buy it lawfully from licensed dispensaries, but hemp shops and online sellers cannot lawfully sell it to Montana consumers.

Can smoke shops in Montana sell THCA hemp?

No. SB 375, in force since 5 May 2025, bars selling any hemp product containing total delta-9 THC to a consumer unless the FDA has authorised it as a food or drug. The law covers products intended for smoking and vaping, so THCA flower and vapes are caught.

How much THCA can I possess in Montana?

THCA flower is treated as marijuana, so the adult-use possession limits apply to people 21 and over. Under MCA 16-12-106, adults may possess up to 1 ounce of usable marijuana, of which no more than 8 grams may be concentrate, plus up to 800 mg of THC in solid edibles.

Sources

1. Montana Legislature. MCA 80-18-101, Definitions (hemp) (Montana Code Annotated 2025). leg.mt.gov
2. Montana Legislature. MCA 50-31-239, Sale of hemp product containing THC to consumers prohibited (SB 375, Ch. 394, L. 2025, effective on approval 5 May 2025). leg.mt.gov
3. Montana Legislature. MCA 16-12-117, Synthetic cannabinoid products prohibited; restriction on sale of marijuana products (Montana Code Annotated 2025; enacted by HB 948, Ch. 746, L. 2023; amended by HB 49, Ch. 100, L. 2025). leg.mt.gov
4. Montana Department of Revenue. 2025 Legislative Updates: New Cannabis Laws in Montana. revenue.mt.gov

Editorial note: This page is general legal information, not legal advice, and reflects our reading of Montana 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 →