Cannabis law in Montana (2026)
Last reviewed: 9 October 2026
In short: Adults aged 21 or over may possess up to 1 ounce of usable marijuana and grow two mature plants and two seedlings at home. Sale is through licensed dispensaries, and public use is prohibited.
| Rule | What applies |
|---|---|
| Possession for personal usePersonal use by an adult | Permitted within limits [1] |
| Quantity limitsPersonal use by an adult | Up to 1 ounce of usable marijuana, or 8 grams of concentrate. [1] |
| Growing at homePersonal use by an adult | Permitted within limits [1] |
| Sale to consumersPersonal use by an adult | Licensed retail stores for adults [2] |
| Use or carrying in public placesPersonal use by an adult | Prohibited [3] |
| Medical cannabisPersonal use by an adult | Legal for medical use [1] |
| VisitorsPersonal use by an adult | Some rules for residents only [2] |
| Minimum agePersonal use by an adult | 21 years [2] |
| Purchase limit in licensed shopsPersonal use by an adult | Per transaction up to 1 ounce of flower, 8 grams of concentrate, 800 mg of infused non-ingestible products or 800 mg THC in edibles. [2] |
| Driving after cannabis usePersonal use by an adult | Driving under the influence of any drug is an offence, and so is driving with a blood THC level of 5 ng/ml or more (inactive metabolites excluded). Drivers under 21 may not have any THC in their body. [4] |
Notes
- The statute caps concentrated forms at 8 grams. A person under 21 without registration is punished under 45-5-639.
- Simultaneous cultivation at a residence is capped at twice the per-person number. Plants visible by unaided vision from a public place carry a civil fine of up to $250 and forfeiture. Registered cardholders may grow four mature plants and four seedlings.
- Not all counties allow adult-use sales; the Department lists counties that permit them. The Department's FAQ states that purchase of medical and adult-use marijuana is legal for individuals 21 and over.
- Smoking marijuana in a public place outside a licensed area carries a civil fine of up to $50 under 16-12-106(4). The Department says no public place has been approved for consumption.
- The medical marijuana programme operates alongside adult use through registered cardholders. The programme's registration rules were not read.
- The Department's visitor checklist says only Montana residents can grow cannabis at home; purchase from licensed dispensaries requires age 21 and valid government-issued ID.
Sources
- Montana Legislature (Montana Code Annotated): 16-12-106. Personal use and cultivation of marijuana -- penalties, MCA (consulted 9 October 2026) · all sources
- Montana Department of Revenue (Cannabis Control Division): Welcome to Montana! Cannabis Use Checklist for Visitors (consulted 9 October 2026) · all sources
- Montana Department of Revenue (Cannabis Control Division): Cannabis Frequently Asked Questions (consulted 9 October 2026) · all sources
- Montana Legislature: Montana Code Annotated 61-8-1002 Driving under influence (consulted 10 October 2026) · all sources
National rules that also apply
These rules are set at national level in the United States and apply here too, alongside the rules above. All national rules for the United States
| Possession for personal use | Criminal offence (source: U.S. Government Publishing Office (govinfo)) |
|---|---|
| Growing at home | Prohibited (source: U.S. Government Publishing Office (govinfo)) |
| Sale to consumers | Prohibited (source: U.S. Government Publishing Office (govinfo)) |
Montana and neighbouring states
| State | Possession for personal use | Growing at home | Sale to consumers | Use or carrying in public places | Medical cannabis | Visitors |
|---|---|---|---|---|---|---|
| Montana | Legal for adults 21+, within limits | Yes: 2 mature plants, 2 seedlings | Licensed dispensaries | Banned in public places | Medical programme (registered cardholders) | Visitors may buy; only residents grow |
| Idaho | Illegal; penalties under the Controlled Substances Act | No (illegal to manufacture) | No legal sale | Illegal in public | No medical programme | — |
| North Dakota | Infraction under 1/2 oz (fine only) | Prohibited | Prohibited (medical centres only) | — | Registered patients, licensed centres | Out-of-state card holders (medical) |
| South Dakota | Criminal offence (misdemeanour up to 2 oz) | ⚠ Not yet verified | Prohibited (medical dispensaries only) | — | Registered cardholders | Non-resident medical cardholders protected |
| Wyoming | Criminal offence (misdemeanour) | Prohibited (misdemeanour) | Supply is an offence | — | No medical programme | — |
More rules in Montana
- Car speed limitsBuilt-up areas: 25 mph · Outside built-up areas (single carriageway): 70 mph day / 65 night
- Minimum age for a car driving licenceMinimum age for a car licence: 15 (after 6 months on a learner licence) · Earliest age to drive a car supervised: 14.5 with a traffic education course
- E-bikes and speed pedelecsLegal class: Bicycle (one class)
- FireworksConsumers may buy and use category F2 fireworks: Yes (permissible fireworks)
- Knives and pepper sprayFolding pocket knives: Carry offence covers firearms only · Locking or one-handed knives: No section on automatic knives listed
- Statutory minimum wageNational statutory minimum wage: Yes · Current adult minimum wage (gross): $10.85 per hour
- Seat belts and child seatsSeat belt compulsory in front seats: Yes, every designated seat · Seat belt compulsory in rear seats: Yes, every designated seat
- Tobacco and nicotine age limitsMinimum age to buy tobacco: 21 · Minimum age to buy e-cigarettes: 21
- Drinking age and alcohol salesMinimum age to buy beer and wine: 21 (sales/provision banned) · Minimum age to buy spirits: 21 (sales/provision banned)
- Drink-driving limitsBlood alcohol limit for ordinary drivers: 0.08% · Lower limit for novice or young drivers: 0.02% under 21
Related pages
General information, not legal advice. Rules change: check the official source before you fly or ride.