Most DUI cases are about what a test showed and what an officer saw. A case with a crash or a child in the vehicle is about something more, and Montana law treats it that way. The charge may change, the court may change, and the range of punishment can rise from days to years. This page sets out the separate offenses. It is part of our Montana DUI Guide.
A Passenger Under 16: Higher Misdemeanor Penalties
If one or more passengers under 16 years old were in the vehicle, the minimums and fines in MCA § 61-8-1007 go up. The offense is still a misdemeanor DUI for a first, second, or third offense.
| Charge, with a passenger under 16 | Jail | Fine |
|---|---|---|
| Impairment DUI, first | 48 consecutive hours to 1 year | $1,200 to $2,000 |
| Impairment DUI, second | 14 days to 1 year | $2,400 to $4,000 |
| Impairment DUI, third | 60 days to 1 year | $5,000 to $10,000 |
| Per se DUI, first | Up to 6 months, no jail minimum | $1,200 to $2,000 |
| Per se DUI, second | 10 days to 1 year | $2,400 to $4,000 |
| Per se DUI, third | 60 days to 1 year | $5,000 to $10,000 |
| Aggravated DUI, first | 4 consecutive days to 1 year | $2,000 |
| Aggravated DUI, second | 45 days to 1 year | $5,000 |
| Aggravated DUI, third | 90 consecutive days to 1 year | $10,000 |
Source: MCA § 61-8-1007(1), (2), and (4). For what "impairment," "per se," and "aggravated" mean, see Montana DUI terms and limits.
Criminal Child Endangerment
Separately from the enhanced DUI penalties, MCA § 45-5-628(1)(e) makes it a felony to cause substantial risk of death or serious bodily injury to a child under 14 by driving under the influence, or committing aggravated DUI, with the child in the vehicle. The penalty is a fine of up to $50,000, imprisonment in the state prison for up to 10 years, or both.
Note the two different ages. The DUI enhancement applies to a passenger under 16. Child endangerment applies to a child under 14 and requires proof of substantial risk. A DUI with a child in the car also tends to surface in family court, which our page on jobs, licenses, gun rights, and custody discusses.
When Someone Is Hurt or Killed
| Offense | MCA | Penalty |
|---|---|---|
| Negligent vehicular assault, bodily injury | § 45-5-205 | Fine up to $1,000, up to 1 year in county jail, or both, plus restitution |
| Negligent vehicular assault, serious bodily injury | § 45-5-205 | Fine up to $10,000, up to 10 years, or both |
| Vehicular homicide while under the influence | § 45-5-106 | Up to 30 years in state prison, a fine up to $50,000, or both. No deferral. |
| Aggravated vehicular homicide while under the influence | § 45-5-107 | 3 to 30 years, a fine of $10,000 to $50,000, or both. The first 3 years may not be suspended. |
| Criminal child endangerment by DUI | § 45-5-628(1)(e) | Fine up to $50,000, up to 10 years in state prison, or both |
Each of the crash offenses has negligence and causationbuilt into it. Negligent vehicular assault requires that the person negligently operated a vehicle while under the influence and caused the injury. Vehicular homicide requires that the person negligently caused the death while driving in violation of the DUI statute. Impairment alone is not the whole case, and causation is often where these cases are fought: road conditions, the other driver's conduct, speed, sight lines, and what a crash reconstruction can and cannot establish.
For vehicular homicide while under the influence, the 2025 Legislature also made restitution for a victim's surviving minor child mandatory. A conviction for negligent vehicular assault brings a 1-year license revocation (MCA § 61-5-205).
Which Court Hears the Case
A misdemeanor DUI, including one with a passenger under 16, is heard in Missoula Municipal Court or Missoula County Justice Court. A felony is prosecuted in district court. For Missoula and Mineral counties that is the Fourth Judicial District Court. A felony case typically begins with an initial appearance in Justice Court before it moves up. Our DUI court process page explains the stages.
These Convictions Follow You Into Later Cases
- A conviction for negligent vehicular assault or for criminal child endangerment by DUI counts as a prior when counting DUI offenses (MCA § 61-8-1011(1)(d)).
- Any prior conviction for vehicular homicide while under the influence, or the aggravated version, makes a later DUI a felony regardless of the count (MCA § 61-8-1008).
What to Do, and Not Do, After a DUI Crash
- Do not give statements about the crash to investigators, the other driver's insurer, or anyone else before you have talked to a lawyer.
- Keep every document: the citation, bond conditions, tow and repair records, and medical records if you were hurt too.
- Follow your release conditions exactly. In a crash case they often include no alcohol and monitoring.
- Mind the license deadline. If you refused a test, you have 30 days to petition the district court (MCA § 61-8-1017).
This page explains Montana law in general as of the 2025 Montana Code Annotated. It is not legal advice about your specific case.