Last verified: March 2026
Complete Possession & Purchase Limits
Montana's possession limits differ significantly between recreational and medical users. Medical patients enjoy higher limits, no potency caps, and a lower tax rate — one reason Montana retains nearly 15,000 medical cardholders even with recreational access available.
| Category | Recreational (21+) | Medical (with card) |
|---|---|---|
| Flower | 1 ounce per transaction | 1 oz/day, 5 oz/month |
| Concentrates | 8 grams | No potency cap |
| Edibles | 800 mg THC (100mg/pkg, 10mg serving → 5mg July 2026) | No potency cap |
| Home plants | 2 mature + 2 seedlings (4+4 per household) | 4 mature + 4 seedlings each |
| Tax rate | 20% + up to 3% local | 4% |
Flower THC capped at 35% for recreational. HB 636 reduces edible servings to 5mg effective July 1, 2026.
Recreational Limits Explained
Per Transaction Limits
Montana uses per-transaction limits rather than daily purchase limits for recreational buyers:
- 1 ounce (28g) of flower per transaction
- 8 grams of concentrates per transaction
- 800mg of THC in edibles per transaction
All recreational transactions are tracked through the Metrc seed-to-sale system. The per-transaction approach means there is no explicit daily limit on the number of transactions, but Metrc tracking flags unusual purchasing patterns.
THC Potency Cap: 35% Flower
Recreational flower is capped at 35% THC. This is a significant restriction for consumers accustomed to high-potency products in other states. A 2025 bill (SB 443) attempted to lower this to 15% but failed. The 35% cap does not apply to concentrates or edibles — only to flower.
Edible Limits
- Current (through June 2026): 100mg THC per package, 10mg per serving
- After July 1, 2026 (HB 636): 100mg per package, 5mg per serving
- Transaction limit: 800mg THC total
Medical Patient Limits
Medical cardholders have substantially more generous limits:
- 1 ounce per day
- 5 ounces per month
- No THC potency caps on any product
- No edible serving size restrictions
- 4 mature + 4 seedlings for home cultivation (vs. 2+2 recreational)
These enhanced limits are a major reason to maintain a medical card. See our Medical Program page for full details.
What You Cannot Possess
Even with legal cannabis, several things remain illegal:
- Cannabis on federal land — Glacier National Park, Yellowstone, national forests, BLM land, and military installations are under federal jurisdiction. Any cannabis is a federal misdemeanor.
- Cannabis crossing state lines — Montana borders no legal recreational states (Idaho, Wyoming, North Dakota, and South Dakota all prohibit recreational cannabis). Crossing any state line with cannabis is a federal offense.
- Unlicensed cannabis — Purchasing from unlicensed sources is illegal regardless of the amount.
- Open containers in vehicles — Cannabis must be in sealed original packaging during transport. Treat it like an open container of alcohol.
| Offense | Penalty |
|---|---|
| Public consumption | Up to $50 fine + forfeiture |
| Excess home plants | Up to $250 fine |
| DUI first offense (5 ng/mL per se) | 24 hrs–6 months, $600–$1,000 |
| DUI under 21 (zero tolerance, SB 508) | Any detectable THC = DUI |
| Possession on federal land | Federal misdemeanor |
| Volatile solvent extraction at home | Prohibited (BHO banned) |
Official Sources
For in-depth cannabis education, dosing guides, safety information, and research summaries, visit our partner site TryCannabis.org