Cannabis DUI Laws in Montana
This state sets a specific THC blood concentration limit. Drivers at or above this level are legally considered impaired.
DUI Law Details
24 hours to 6 months in jail, fines $600-$1,000, 6-month license suspension
6-month license suspension
Overview
Montana established a per se THC limit of 5 nanograms per milliliter of blood alongside its recreational cannabis legalization in 2020. Drivers at or above this threshold are considered to be driving under the influence.
Montana uses blood testing to measure THC levels, supplemented by field sobriety tests and DRE evaluations. The state's per se limit is consistent with the limits set by Colorado and Washington, creating a regional standard in the western United States.
Key Facts
- •Per se limit: 5 ng/mL active THC in blood
- •Recreational cannabis legalized in 2020
- •First offense carries 24 hours to 6 months in jail
- •6-month license suspension for test refusal
- •Same THC limit as Colorado and Washington
Frequently Asked Questions
What is Montana's THC driving limit?+
What are the penalties for a first cannabis DUI in Montana?+
How does Montana test for THC?+
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Disclaimer: The information on this page is provided for educational and informational purposes only and does not constitute legal advice. Cannabis remains illegal under US federal law. Montana DUI laws and regulations are subject to change and may vary by local jurisdiction. THC limits, penalties, and testing methods described here are based on publicly available information and may not reflect the most current regulations. Always verify current laws with official Montana state resources and consult with a qualified attorney for legal guidance. Cannabismarketcap does not guarantee the accuracy or completeness of any information presented.