Montana's DUI Laws and Conviction Penalties

Learn about the penalties for a DUI conviction in Montana.

In Montana, the penalties you'll face for a DUI conviction depend mainly on how many prior convictions you have. This article explains Montana's DUI laws (including important definitions) and the consequences of a first, second, third, and felony DUI conviction.

Montana's DUI Law

Montana prohibits anyone from driving or being in actual physical control of a vehicle:

  • with a blood alcohol concentration (BAC) of .08% or more
  • with a delta-9-tetrahydrocannabinol (THC) level of 5 ng/ml or more, or
  • while under the influence of drugs, alcohol, or any impairing substance (or a combination thereof) to a degree that renders the person incapable of safely driving a vehicle.

However, each of these prohibitions is actually considered a separate offense in Montana. A DUI, driving with excessive BAC, and driving with excessive THC are all governed by different statutes, with similar— but different—punishments.

Montana's BAC Limits

An excessive BAC is normally at or above .08%. However, this threshold is reduced to .04% for commercial drivers and .02% for drivers under 21 years old. But note that the penalties for underage DUI are generally less severe than those for a normal DUI conviction, and a commercial DUI can result in additional consequences for the driver such as commercial license disqualification.

The amount of alcohol a person must drink to exceed the legal BAC limit depends on a number of circumstances. These include gender, body size, and the number and type of drinks. For instance, the BAC of a small person might be higher than a bigger person who had the same number of drinks.

Montana's First DUI Penalties—Misdemeanor

In Montana, a first DUI within 10 years generally carries:

  • up to six months in jail (minimum of 24 hours for DUIs based on actual impairment)
  • $600 to $1,000 in fines, and
  • a six-month license suspension.

For a first offense where there was a passenger in the vehicle who was under 16 years old, the driver faces 48 hours to one year in jail and $1,200 to $2,000 in fines.

A DUI will be elevated to an aggravated DUI if the driver's BAC was .16% or greater or the driver refused a chemical test, has a pending DUI charge, or currently has a suspended or restricted license due to a DUI. The penalties for an aggravated DUI include 48 hours to one year in jail and a $1,000 fine.

All persons convicted of DUI must also obtain an alcohol and drug evaluation. For most first-offense DUIs, the offender will be required to take a chemical dependency education course, but treatment can be ordered under certain circumstances. The judge may also order chemical testing such as random drug screens or an alcohol-monitoring ankle bracelet.

Montana's Second DUI Penalties—Misdemeanor

In Montana, a second DUI within 10 years generally carries:

  • five days to one year in jail (minimum of seven days for DUIs based on actual impairment)
  • $1,200 to $2,000 in fines, and
  • a one-year license suspension.

A second offender who had a child under the age of 16 in the vehicle faces 14 days to one year in jail and $2,400 to $4,000 in fines.

For second offenses involving a BAC of .16% or greater or where the driver refused a chemical test, has a pending DUI charge, or currently has a suspended or restricted license because of a DUI, the penalties are 15 days to one year in jail and a $2,500 fine.

For most second-offense DUIs, the offender will be required to take a chemical dependency treatment course, which can vary based on the chemical dependency of the convicted person. The judge will also order chemical testing, which may consist of random drug screens and/or an alcohol-monitoring ankle bracelet.

Montana's Third DUI Penalties—Misdemeanor

In Montana, a third DUI within the driver's lifetime generally carries:

  • 30 days to one year in jail
  • $2,500 to $5,000 in fines, and
  • a one-year license suspension.

A third offender who had a child under the age of 16 in the vehicle faces 60 days to one year in jail and $5,000 to $10,000 in fines.

For third offenses involving a BAC of .16% or greater or where the driver refused a chemical test, has a pending DUI charge, or currently has a suspended or restricted license because of a DUI, the penalties are 40 days to one year in jail and a $5,000 fine.

For most third-offense DUIs, the offender will be required to take a chemical dependency treatment course, which can vary depending on the results of the offender's evaluation. The judge will also order chemical testing that will likely consist of random drug screens and/or an alcohol-monitoring ankle bracelet.

Montana's Felony DUI Penalties—4th Offense, Injuries, and Deaths

A fourth or subsequent DUI is a felony and carries up to five years in prison and $5,000 to $10,000 in fines. Offenders convicted of a fifth or subsequent DUI face 13 months to five years in prison and $5,000 to $10,000 in fines.

Causing bodily injury to another person while driving under the influence is considered to be "negligent vehicular assault." When the injuries are serious, negligent vehicular assault is a felony and carries up to ten years in prison and a maximum $10,000 in fines.

Negligently causing the death of another person while driving under the influence is "vehicular homicide" and a felony. A conviction carries up to 30 years in prison and a maximum $50,000 in fines.

Montana's Underage DUI Laws

Underage drivers can be cited for an underage DUI for operating a vehicle with a BAC of .02% or more. An underage DUI violation will result in the following consequences:

  • for a first violation, the driver faces a fine of $100 to $500 and a 90-day license suspension.
  • for a second violation, the driver is looking at $200 to $500 in fines, a six-month license suspension, and up to ten days in jail (if at least 18 years old).
  • for a third violation or subsequent offense, the driver will be facing $300 to $500 in fines, a one-year license suspension, and one to 60 days in jail (if at least 18 years old).

All offenders must also complete substance abuse education and treatment.

Probationary Licenses and Ignition Interlock Devices in Montana

The judge is permitted to grant the convicted the usage of a probationary license. This license permits the holder to drive for certain purposes with an ignition interlock device (IID) installed in the vehicle. Before being eligible, the convicted motorist must complete at least 45 days of suspension for a second offense and 90 days of suspension for a third offense.

Administrative License Suspension for Refusing a Blood or Breath Test in Montana

Montana's "implied consent" laws require all drivers lawfully arrested for a DUI to submit to a blood or breath test. Depending on the situation, this implied consent might extend to blood draws, in-station breathalyzer tests, and roadside preliminary breath tests. Refusal of a legally-requested test will result in license suspension.

Talk to a Montana DUI Attorney

If you've been arrested for driving under the influence, you should seek legal assistance. A qualified DUI lawyer can review your case and help you decide on the best course of action.

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