Summary of Montana Driving Under the Influence Statutes

What follows is a brief outline of Montana’s DUI laws. Although written to be easily understood, this outline will not provide enough information or detail to evaluate the merit or quality of a DUI case, nor is it meant to be a complete and total resource for DUI laws in Montana.

It is vital to act quickly when charged with a DUI in Montana, particularly if you have refused breath / blood testing, in which you only have thirty (30) days to challenge the administrative suspension of your driver’s license. Please contact a National College of DUI Defense member attorney for further assistance is defending against a DUI charge or for more information about driving under the influence.

Driving under the Influence – (Mont. Code Ann. § 61-8-1002)

(1) A person commits the offense of driving under the influence if the person drives or is in actual physical control of:

(a) a vehicle or a commercial motor vehicle upon the ways of this state open to the public while under the influence of alcohol, any drug, or a combination of alcohol and any drug;

(b) a noncommercial vehicle upon the ways of this state open to the public while the person's alcohol concentration, as shown by analysis of the person's blood, breath, or other bodily substance, is 0.08 or more;

(c) a commercial motor vehicle within this state while the person's alcohol concentration, as shown by analysis of the person's blood, breath, or other bodily substance, is 0.04 or more;

(d) a noncommercial vehicle or commercial motor vehicle within this state while the person's tetrahydrocannabinol level, excluding inactive metabolites, as shown by analysis of the person's blood or other bodily substance, is 5 ng/ml or more; or

(e) a vehicle within this state when the person is under 21 years of age at the time of the offense while the person's alcohol concentration, as shown by analysis of the person's blood, breath, or other bodily substance, is 0.02 or more.

(Mont. Code Ann. § 61-8-1002)

Proving a DUI in Montana requires that the State prove beyond a reasonable doubt that an individual was impaired—that the individual’s ability to operate a motor vehicle was diminished due to alcohol and/or drugs. This applies to both regular vehicles and commercial motor vehicles.

Proving a DUI per se in Montana does not require a showing of impairment, only that an individual’s blood alcohol (BAC) or breath alcohol (BrAC) was above a certain limit.

• For noncommercial vehicles, the “legal limit” is 0.08.
• For commercial motor vehicles, the “legal limit” is 0.04
• For individuals under 21 years of age, the “legal limit” is 0.02.
• Additionally, if a person's tetrahydrocannabinol (THC) level is 5 ng/ml or higher, they can be charged with DUI per se.

In legal proceedings related to DUI, the concentration of alcohol in a person's blood, breath, or other bodily substance, as determined by a test conducted within a reasonable time after the alleged offense, can be used to make certain conclusions:

(a) If the alcohol concentration is 0.04 or lower, it can be inferred that the person was not under the influence of alcohol.

(b) If the alcohol concentration is higher than 0.04 but lower than 0.08, this fact alone cannot be used to determine if the person was under the influence of alcohol. However, it can be considered along with other evidence to decide the person's guilt or innocence.

(c) If the alcohol concentration is 0.08 or higher, it can be inferred that the person was under the influence of alcohol. However, this inference can be challenged and refuted.

Nothing above prevents the introduction of other relevant evidence that can be used to determine whether a person was under the influence of alcohol, drugs, or a combination of both.

A person may not be convicted of a DUI based upon the presence of a drug or drugs in the person unless some other competent evidence exists that tends to establish that the person was under the influence of a drug or drugs while driving or in actual physical control of a motor vehicle within this state. See State v. Larsen, 2010 MT 230, ¶ 56.

The Montana Supreme Court has now required that in a DUI of alcohol case, this same requirement of corroborative competent of impairment must be introduced. See State v. Michaud, 2008 MT 88.

Penalty for DUI (First through Third Offenses) (M.C.A. 61-8-1007)

If a person is convicted of a first DUI, they may face imprisonment for at least 24 hours or up to 6 months, along with a fine ranging from $600 to $1,000. However, if there were passengers under the age of 16 in the vehicle at the time of the offense, the punishment increases to at least 48 consecutive hours in jail or up to 1 year, and a fine ranging from $1,200 to $2,000.

For a second offense, the imprisonment period increases to at least 7 days or up to 1 year, with a fine ranging from $1,200 to $2,000. Again, if passengers under 16 were present, the punishment becomes at least 14 days in jail or up to 1 year, and a fine ranging from $2,400 to $4,000.

A third offense results in imprisonment for at least 30 days or up to 1 year, with a fine ranging from $2,500 to $5,000. If passengers under 16 were in the vehicle, the punishment becomes at least 60 days in jail or up to 1 year, and a fine ranging from $5,000 to $10,000.

There are additional provisions if the person has previous convictions or charges related to DUI. The judge may impose harsher penalties based on those prior offenses.

The mandatory minimum imprisonment term cannot be served under home arrest or suspended unless the judge determines that it would harm the person's well-being. However, the remaining imprisonment sentence may be suspended for up to 1 year if the person successfully completes a chemical dependency treatment program.

Regardless of the specific offense, the person must comply with chemical dependency education and treatment provisions as ordered by the court. The person's driver's license may also be suspended for a certain period depending on the number of convictions.

Tests for Alcohol and Drugs/Implied Consent (Mont. Code Ann. § 61-8-1016)

If a person is driving a vehicle on a road open to the public (which can include private roads and parking lots), they are considered to have given consent for tests to check their breath or blood for alcohol or drugs.

The officer can choose which tests to administer and must inform the driver of the right to refuse. However, refusing the tests will result in a suspension of the driver’s license for up to 1 year.

Administration of Tests (Mont. Code Ann. § 61-8-1019)

Only certain trained medical professionals, like doctors or registered nurses, can draw blood for the purpose of checking for alcohol or drugs in a person's system.

If someone wants an independent blood sample to be taken to determine alcohol or drug levels in their system, they can request it and police cannot unreasonably prevent them from getting an independent test. The person is responsible for paying for the independent test, and if they fail to get one, any test conducted by the police can still be used as evidence.

If a police officer has reasonable grounds to suspect that a person has violated certain driving laws or is driving under the influence, and a sample of their bodily substance is taken for medical or other purposes, a portion of that sample may be provided to police at their request.

Admissible Evidence (Mont. Code Ann. § 61-8-1018)

If someone is being tried for a DUI offense, evidence of alcohol, drugs, or a combination of both found in their breath or blood can be presented in court. However, just having a positive test result for these substances doesn't automatically mean the person was under their influence while driving. There needs to be other evidence that shows the person was impaired by the substances at the time they were in control of a vehicle.

Reports of tests conducted on a person's breath or blood can be used as evidence if the tests were performed by someone certified by the forensic sciences division or if a blood sample was analyzed in a laboratory operated or certified by the relevant department. The blood sample must have been collected by a competent person. Reports of physical, psychomotor, or physiological assessments of a person (standardized field sobriety testing) can be presented as evidence if they were conducted by someone trained or recognized by the department.

If a person who was arrested for DUI refuses to take one or more tests, that refusal can be used as evidence in a criminal case. The fact that they refused the tests can lead the judge or jury to infer that the person was under the influence. However, this inference can be challenged or disputed.