Montana DUI Laws

Montana places drunk driving under the state per se law. If your blood alcohol level is at or above the legal limit within two hours of operating a motorized vehicle, you will be arrested on a DUI. In Montana, a DUI will result in multiple fines and penalties. Drivers with a BAC of .04% or more may receive a DUI depending upon the circumstances surrounding the arrest. All DUI convictions have a mandatory jail time, license suspension, and court ordered substance abuse treatment attached to the charge. The penalties will be more severe if a minor under the age of 16 is in the vehicle at the time of the arrest. Montana DUI laws are strictly adhered to and the penalties and fines are increased for repeat offenders. These rules apply to other substances such as drugs and inhalants.

Montana’s implied consent law will result in the loss of your driver’s license for 6 months to 1 year if your refuse to take a blood alcohol, breath or urine test. Operating a motorized vehicle on Montana roads is your acceptance of taking a chemical test if stopped for impaired driving. You will have to pay fines and administrative fees to get the vehicle back. You may also be required to install the Ignition Interlock Device (IID) on your vehicle at your own expense.

The BAC for Montana is .08% or higher. A BAC of .15% or higher is considered extreme DUI and the penalties will be more severe. Montana has a zero tolerance law in place for underage drinkers. This includes anyone under 21. Underage drinkers caught driving with a BAC more than 0.0% will be charged with a DUI. Over the counter cough medicine can put you over the limit. The BAC for commercial drivers, this is anyone hauling merchandise or people, is .04%. Your fourth arrest for DUI becomes a felony in the state of Montana. The penalties for a DUI will depend upon the circumstances of the arrest.



Your first DUI conviction will result in 24 hours to 6 months in jail. This sentence increases to 48 hours to 12 months of jail time if a passenger under the age of 16 is in the vehicle. Your fines may be $300.00 to $1,000.00 or $600.00 to $2,000.00 if a minor under the age of 16 was in the vehicle. Your license will be suspended for 6 months. After your suspension has been served, you will be required to install the IID on your vehicle at your own expense in order to get a probationary license. You will also be required to complete a chemical dependency education or treatment program.

Your second conviction will result in 7 days to 6 months of jail time. This sentence increases to 14 days to 12 months if a passenger under the age of 16 is in the vehicle. Your fines may be $600.00 to $1,000.00 or $1,200.00 to $2,000.00 if a minor under the age of 16 was in the vehicle. Your license will be suspended for 1 year. After you have served 45 days of your suspension, you will be required to install the IID on your vehicle at your own expense in order to get a probationary license. On the other hand, your vehicle may be taken by the state. You will also be required to complete a chemical dependency education or treatment program.

Your third conviction will result in30 days to 1 year of jail time. This sentence increases to 60 days to 12 months if a passenger under the age of 16 is in the vehicle. Your fines may be $1,000.00 to $5,000.00 or $2,000.00 to $10,000.00 if a minor under the age of 16 was in the vehicle. Your license will be suspended for 1 year. After you have served 45 days of your suspension, you will be required to install the IID on your vehicle at your own expense in order to get a probationary license. On the other hand, your vehicle may be taken by the state. You will also be required to complete a chemical dependency education or treatment program.

Your fourth DUI conviction in the state of Montana is considered a felony. It may result in a 5 year jail sentence and a $10,000.00 fine.