Montana Cannabis Laws 2026: What's Legal for Adults and Patients

Montana voters approved medical cannabis in 2004 and recreational cannabis with I-190 in 2020. Adult-use sales began on January 1, 2022. The Department of Revenue's Cannabis Control Division regulates the market.

Is weed legal in Montana?

Yes, for adults 21 and older. Bring a valid ID showing you're 21+. Visitors can buy too. Some counties have voted not to allow adult-use stores, so check before you go.

How much can you carry?

Limit	Adults 21+
Flower	Up to 1 ounce
Concentrate	Up to 8 grams

Carrying more than 1 ounce, up to 2 ounces, is a civil infraction with a fine.

Where can you use it?

Private property, with the owner's permission. Public use is illegal and brings a fine. Montana has a lot of federal land, including Glacier and Yellowstone national parks, where cannabis is illegal. Landlords can ban smoking and growing.

Can you grow cannabis at home?

Yes. Adults 21+ can grow 2 mature plants and 2 seedlings, with a limit of 4 mature plants and 4 seedlings per home. Plants must be out of public view, and your home has to be your primary residence.

Medical cannabis in Montana

Patients with a qualifying condition can register with the state. Medical purchases carry a much lower 4% tax, and patients can grow more plants than adult-use customers.

Taxes on cannabis in Montana

Adult-use purchases carry a 20% state tax, plus up to 3% local tax in some counties. Since 2025, the tax is calculated on the price after discounts. Medical purchases are taxed at 4%.

Driving and work

Driving impaired is illegal. Employers can keep drug-free workplace policies.

Old marijuana convictions

I-190 lets people ask the court to expunge or resentence past cannabis convictions for conduct that's now legal.

Is anything changing in 2026?

Yes, new product rules. As of July 1, 2026, adult-use edibles are capped at 5 mg of THC per serving and 100 mg per package (adult-use flower remains capped at 35% total THC), and stores must use new warning labels and display addiction-resource posters. Possession and home-grow limits haven't changed.

Federal law in 2026

Federal law still treats recreational cannabis as illegal. In April 2026, the federal government moved marijuana sold under a state medical license (and FDA-approved cannabis medicines) to Schedule III, but adult-use cannabis is still Schedule I. That means it's still banned on federal land and can't legally cross state lines, even between two legal states.

Separately, a federal ban on intoxicating hemp products takes effect in two steps: synthetic and converted cannabinoids like delta-8 lose their legal status on November 12, 2026, and naturally derived hemp THC (THCA flower, hemp delta-9 edibles and drinks) on December 11, 2026.

Where to buy legally

Browse dispensaries in Montana in our directory, including Missoula and Helena.

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Last reviewed October 8, 2026. This guide is general information, not legal advice. Laws change, so check the official sources below before you rely on any detail.