A first DUI conviction in Montana carries the prospect of both criminal and administrative penalties for defendants. The penalties noted below do not address those applicable to commercial driver’s license holders, juvenile offenders, or underage drinkers in violation of zero tolerance laws.
Though a misdemeanor, a third offense DUI in Montana (within 10 years) carries serious administrative and criminal penalties including minimum jail time. A refusal to submit to a blood test for a third DUI arrest will lead to an automatic DUI charge. A third offense DUI also includes possible vehicle seizure.
Sobriety checkpoints are legal in Montana ("Safety spot checks" are authorized by Mont. Code Ann. § §46-5502. The statute authorizes checks for licenses, registration, insurance, and identification). These checkpoints (also referred to as "mobile checkpoints" or "roadblocks") are police traffic stops that are not tied to any specific or individual suspicions.