DUI Laws in Montana

Montana DUI Laws: Key Facts

Legal limit (adults)

0.08 BACMont. Code Ann. § 61-8-1002; § 61-8-1001 (aggravated DUI definition)

Commercial drivers (CDL)

0.04 BAC

Drivers under 21

0.02 BAC (0.02 or more, or any amount of THC, for a driver under 21)

Enhanced penalties from

0.16 BAC

Lookback period

10 years

Montana DUI Penalties by Offense

First offense: Mont. Code Ann. § 61-8-1007; § 61-5-208 (suspension); § 61-8-1010 (interlock) · Second offense: Mont. Code Ann. § 61-8-1007; § 61-5-208; § 61-8-1010 · Third offense: Mont. Code Ann. § 61-8-1007; § 61-5-208; § 61-8-1010

When Penalties Are Higher

• aggravated DUI: alcohol concentration 0.16 or more, or driving while under an interlock order, while suspended or revoked for a prior DUI, or refusing a breath test when your license was previously suspended or revoked under an implied consent law: first offense 2 days to 1 year and $1,000 fine; second 15 days to 1 year and $2,500; third 40 consecutive days to 1 year and $5,000Mont. Code Ann. § 61-8-1001; § 61-8-1007
• passenger under 16 in the vehicle: minimum and maximum penalties roughly double: first offense 48 consecutive hours to 1 year and $1,200 to $2,000; second 14 days to 1 year and $2,400 to $4,000; third 60 days to 1 year and $5,000 to $10,000Mont. Code Ann. § 61-8-1007

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If You Refuse a Breath or Blood Test

license seized and suspended 6 months for a first refusal, 1 year for a second or subsequent refusal within 5 years; the officer issues a temporary permit valid 5 days; refusing a breath test after a prior implied consent suspension makes a DUI aggravatedMont. Code Ann. § 61-8-1016; § 61-8-1032

Official source: if you refuse a breath or blood test in Montana

Getting a Probationary License

after a second DUI conviction, only after 45 days of the 1-year suspension and on a court recommendation; after a third or subsequent, only after 90 days and on a court recommendation; none during a refusal suspension

Official source: getting a probationary license in Montana

Ignition Interlock

First offense: discretionary: the court may order it Repeat offenses: for a second or subsequent offense the court must order the 24/7 sobriety program, an interlock restriction (if a probationary license is recommended), or vehicle forfeiture the offender pays the device costs; driving while required to use an interlock makes a new DUI aggravated

Official source: ignition interlock in Montana

Can a DUI Come Off Your Record?

misdemeanor expungement exists once in a lifetime, but it is not presumed for DUI offenses under Title 61, chapter 8, part 10; the court weighs age, time elapsed, rehabilitation and risk of reoffending Waiting period: presumption (for other misdemeanors) requires 5 years without a conviction after completing the sentence petition the district court where convicted; fingerprinting required

Official source: can a dui come off your record? in Montana

Drivers Under 21

a driver under 21 commits an offense at 0.02 or more or with any amount of THC first conviction $100 to $500 fine; license suspended 90 days (first), 6 months (second), 1 year (third or subsequent); chemical dependency education and treatment; does not count as a prior for adult DUI sentencing

Official source: drivers under 21 in Montana

Driving After Using Drugs

yes: the same DUI statute covers any drug, and sets per se nanogram limits for listed controlled substances (for example methamphetamine 20 ng/ml, fentanyl 0.5 ng/ml) without a valid prescription

Official source: driving after using drugs in Montana

More on DUI Law in Montana

• Montana DUI Penalties: First, Second and Third Offense
• DUI License Suspension in Montana: Hearing Deadline and Hardship License
• Ignition Interlock Rules in Montana
• Can a DUI Be Expunged in Montana?
• Refusing a Breath or Blood Test in Montana

Frequently Asked Questions