Montana · DUI · Checked October 2026
Montana DUI Penalties: First, Second and Third Offense
Montana DUI Penalties: What Are the Rules?
Montana sets DUI penalties by offense, and they rise with each conviction.
- First offense jail
- 24 consecutive hours to 6 months
- First offense fine
- $600 to $1,000
- First offense license
- 6 months
- Felony
- A fourth or subsequent DUI conviction (three or more prior DUI or related convictions, counted regardless of age) is a felony: 13 months to 2 years with the Department of Corrections followed by a 5-year suspended prison term, or up to 5 years in a treatment court program, plus a $5,000 to $10,000 fine
- Lookback period
- 10 years
Montana DUI Penalties by Offense
| Penalty | First offense | Second offense | Third offense |
|---|---|---|---|
| Charge | misdemeanor | misdemeanor | misdemeanor |
| Jail | 24 consecutive hours to 6 months | 7 days to 1 year | 30 days to 1 year |
| Fine | $600 to $1,000 | $1,200 to $2,000 | $2,500 to $5,000 |
| License suspension | 6 months | 1 year (probationary license possible after 45 days with court recommendation) | 1 year (probationary license possible after 90 days with court recommendation) |
| Ignition interlock | court may require an ignition interlock or the 24/7 sobriety program | court must order the 24/7 sobriety and drug monitoring program, an ignition interlock restriction, or forfeiture of the person's vehicles | court must order the 24/7 sobriety and drug monitoring program, an ignition interlock restriction, or forfeiture of the person's vehicles |
Other First Offense Penalties in Montana
- chemical dependency assessment, education and treatment required (Mont. Code Ann. § 61-8-1009)
- a per se (0.08 BAC) conviction under § 61-8-1002(1)(b) has a separate schedule: first offense up to 6 months with no minimum jail and 00 to ,000; second 5 days to 1 year
Other Second Offense Penalties in Montana
- chemical dependency treatment must be completed or the suspension stays in effect
Other Third Offense Penalties in Montana
- chemical dependency treatment must be completed or the suspension stays in effect
When Penalties Are Higher in Montana
- 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 $5,000
- 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 $10,000
When a DUI Is a Felony in Montana
a fourth or subsequent DUI conviction (three or more prior DUI or related convictions, counted regardless of age) is a felony: 13 months to 2 years with the Department of Corrections followed by a 5-year suspended prison term, or up to 5 years in a treatment court program, plus a $5,000 to $10,000 fineMont. Code Ann. § 61-8-1008
How Far Back Prior Offenses Count in Montana
10 years. a prior conviction counts if less than 10 years passed between it and the new offense; for a third or subsequent offense, all previous convictions countMont. Code Ann. § 61-8-1011
Official source: how far back prior offenses count (Montana)
More on DUI Law in Montana
See the full overview of DUI laws in Montana and read about first-offense DUI penalties across the states.
This page summarizes Montana law from official sources, checked October 2026. It isn't legal advice; a lawyer licensed in Montana can advise on your case.
Frequently Asked Questions
What Is the Penalty for a First DUI in Montana?
Jail: 24 consecutive hours to 6 months. Fine: $600 to $1,000. License suspension: 6 months.
What Is the Penalty for a Second DUI in Montana?
Jail: 7 days to 1 year. Fine: $1,200 to $2,000. License suspension: 1 year (probationary license possible after 45 days with court recommendation).
When Is a DUI a Felony in Montana?
a fourth or subsequent DUI conviction (three or more prior DUI or related convictions, counted regardless of age) is a felony: 13 months to 2 years with the Department of Corrections followed by a 5-year suspended prison term, or up to 5 years in a treatment court program, plus a $5,000 to $10,000 fine