Montana DUI Laws & Drunk Driving Penalties
Overview of the penalties upon conviction of DUI in Montana
Montana DUI Laws, BAC limits, fines, jail times, IID requirements, suspension/revocation periods and SR22 insurance requirements for first time and repeat offenders with multiple DUI's.
If you've been charged with DUI in Montana, the law allows only 30 days for a Montana DUI Lawyer to make a request with the Montana MVD (Motor Vehicle Division) for a hearing to help save your drivers license.
What are the penalties for DUI in Montana?
The penalties for driving under the influence in Montana will depend upon the exact circumstances of each particular case and the number of previous offenses (if any) a person has.
MT DUI Penalties
Montana is a state with a 10 year 'washout period' also known as a 'look back period' for a first offense. Third and subsequent offenses have lifetime look back periods.
AGGRAVATED DUI: If a driver commits a DUI and:
(1) - the driver has a BAC of 0.16 or more; OR
(2) - the drivers license or privilege to drive is currently suspended, revoked or canceled for a DUI related offense; OR
(3) - the driver is under the requirement to have an approved ignition interlock device equipped; OR
(4) - the driver refuses testing and has previously refused testing within 10 years of the commission of the present offense; OR
(5) - has one previous DUI related conviction or pending charge within 10 years of the commission of the present offense; OR
(6) - has two or more prior convictions or pending charges, or combination thereof.
The penalty will include a maximum jail sentence of 1 year and a maximum fine of $1,000
1st DUI Offense / Conviction - Misdemeanor
The penalty upon conviction of a first DUI offense in Montana:
- Fine: $300 to $1,000 fine
- Jail: 24 hours to 6 months imprisonment
- License Suspension: 6 months drivers license suspension (may be eligible for restricted probationary license with or without an ignition interlock after first 45 days of suspension)
- alcohol assessment
- possible chemical dependency education and/or treatment course
- 10 points added to drivers license record
- MT SR22 Insurance (proof of financial responsibility) Requirement
2nd DUI Offense / Conviction - Misdemeanor
The penalty upon conviction of a second DUI offense in Montana:
- Fine: $600 to $1,000 fine
- Jail: 7 days to 1 year imprisonment
- License Suspension: 1 year drivers license suspension (may be eligible for ignition interlock restricted probationary license after first 45 days of suspension)
- 10 points added to drivers license record
- alcohol assessment
- must complete chemical dependency education and/or treatment course before license will be re-instated
- possible participation in 24/7 sobriety program
- MT SR22 Insurance (proof of financial responsibility) Requirement
3rd DUI Offense / Conviction - Misdemeanor
NOTE: 3 DUI's within 3 years (habitual traffic offender)
A person who accumulates 30 points on their drivers license within a 3 year period for DUI and/or other violations will be declared as an 'habitual traffic offender', this will result in their drivers license being revoked for 3 years.
The penalty upon conviction of a third DUI offense in Montana:
- Fine: $1,000 to $5,000 fine
- Jail: 30 days to 1 year imprisonment
- License Suspension: 1 year drivers license suspension (may be eligible for ignition interlock restricted probationary license after first 90 days of suspension)
- 10 points added to drivers license record
- alcohol assessment
- must complete chemical dependency education and/or treatment course before license will be re-instated
- possible participation in 24/7 sobriety program
- MT SR22 Insurance (proof of financial responsibility) Requirement
4th (& subsequent) DUI Offense / Conviction - Class C Felony
The penalty upon conviction of a fourth or subsequent DUI offense in Montana:
- Fine: $1,000 to $10,000 fine
- Jail: up to 5 years in Montana state prison
- License Revocation: at least 1 year drivers license revocation
- 10 points added to drivers license record
- alcohol assessment
- must complete chemical dependency education and/or treatment course before license will be re-instated
- possible participation in 24/7 sobriety program
- MT SR22 Insurance (proof of financial responsibility) Requirement
Implied Consent (Chemical Testing) Laws

In Montana, if the accused refuses to take a chemical test of their blood, breath or urine, their drivers license will be suspended/revoked.
NOTE: If the arrested person has refused to provide a breath, blood or urine sample in a prior investigation in Montana or under a substantially similar statute in another jurisdiction, or the arrested person has a prior or pending conviction for a DUI offense. A police officer may apply for a search warrant to be issued in order to collect a sample of the persons blood for testing.
NOTE: Refusal to submit to the preliminary alcohol screening test at the roadside can also lead to a drivers license suspension of up to 1 year.
First chemical test refusal
- License Suspension: 6 months drivers license suspension
- MT SR22 Insurance (proof of financial responsibility) Requirement
Second (and subsequent) chemical test refusal
- License Suspension: 1 year drivers license suspension
- Fine: up to $1,000 fine
- Jail: up to 1 year in jail
- MT SR22 Insurance (proof of financial responsibility) Requirement
What is the legal alcohol limit in Montana
The maximum legal BAC (blood alcohol content) limits in Montana for driving are as follows:
ADULT DRIVERS - BAC LIMIT = 0.08%
In the State of Montana it is an offense for adult drivers to drive any regular motor vehicle with 0.08% or more, by weight, of alcohol in his/her blood.
DRIVERS UNDER 21 - BAC LIMIT = 0.02%
In the State of Montana it is an offense for drivers under the age of 21 (minors) to drive any motor vehicle with 0.02% or more, by weight, of alcohol in his/her blood.
COMMERCIAL DRIVERS - BAC LIMIT = 0.04%
In the State of Montana it is an offense for drivers who drive commercial vehicles to drive any commercial motor vehicle with 0.04% or more, by weight, of alcohol in his/her blood.
It is an offense to refuse to submit to a chemical test in Montana and implied consent laws are enforced.
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