Local DUI Laws

Educational information about DUI laws in the United States.

February 3, 2026 | LDUIL

How DMV Hearings Work After a DUI in Montana

After a DUI arrest in Montana, many drivers focus on the court process—but there’s another track that moves forward just as quickly: the administrative license hearing through the Montana Motor Vehicle Division (MVD). Often referred to as a “DMV hearing” (even though it’s handled by the MVD in Montana), this is a separate legal process from the criminal court case. Its purpose is to determine whether your driving privileges will be suspended—regardless of whether you’re convicted of DUI in court.

This post explains how DMV hearings work in Montana after a DUI arrest. It breaks down the process, timeline, requirements, and consequences involved. While the criminal court system handles the DUI charges themselves, the MVD hearing can determine whether—and for how long—your license will be suspended.

We’ll walk through everything that happens during the administrative hearing process, how it’s triggered, what decisions are made, and how it differs from your criminal case. By the end, you’ll have a full understanding of this important but often misunderstood part of the DUI process.

What Triggers an MVD Hearing After a DUI Arrest?

Montana’s MVD administrative hearing process is triggered by two common DUI-related events:

  • You failed a chemical test (breath or blood) with a BAC of 0.08% or higher
  • You refused to submit to a chemical test when requested by law enforcement

In either case, the arresting officer will submit a report to the MVD, and you may be issued a Notice of Suspension. This document informs you that your driving privileges are being suspended under Montana’s implied consent laws—regardless of what happens in criminal court.

You typically receive this notice at the time of arrest or shortly after, and it includes information on how to request a hearing.

Key Points:

  • The hearing process is administrative, not criminal
  • It runs separately from your DUI court case
  • You must act quickly to preserve your rights (within 30 days)

How to Request a DMV Hearing in Montana

If you want to contest the automatic suspension of your license, you must formally request a hearing with the MVD within 30 days of receiving the suspension notice. If you miss this deadline, you lose the right to a hearing, and the suspension takes effect automatically.

To request the hearing, you typically must:

  • Submit a written request to the Montana Department of Justice
  • Include the required personal information and arrest details
  • Mail or deliver the request within the deadline listed on your suspension notice

Once your request is received, the MVD will schedule a hearing and notify you of the date and location.

Important:

  • You do not have to request a hearing—but if you don’t, your license will be suspended by default
  • This hearing does not replace your court case—it only decides the status of your license

What Happens at the MVD Hearing?

The MVD hearing is a civil administrative review to determine if your license should be suspended. It is not about guilt or innocence for DUI charges—that’s handled in criminal court. Instead, the hearing focuses on whether the arresting officer followed proper procedures and whether the chemical test (or refusal) meets the legal standards for license action.

The hearing typically includes:

  • A review of the arresting officer’s report
  • Possible testimony from the officer, especially if requested by the driver
  • Presentation of evidence, such as BAC results or refusal documentation
  • Opportunity for the driver (or their attorney) to present their side

Most MVD hearings are short and focused, often held via phone or in an administrative office. In some cases, the hearing may be waived if both parties agree to proceed based on written documents alone.

At the end of the hearing, the hearing officer will issue a decision, which may include:

  • Upholding the suspension
  • Dismissing the suspension due to procedural issues
  • Adjusting the terms of the suspension

Outcomes of a Montana MVD Hearing

If the hearing officer upholds the suspension, your license will be suspended for:

  • 6 months for a first-time failed test
  • 6 months or more for a test refusal
  • 1 year for repeat offenses or prior refusals

If the officer dismisses the suspension, you will retain your driving privileges—though your criminal DUI case may still result in additional license penalties later.

Other key outcomes:

  • You may become eligible for a restricted license, depending on the case
  • The decision is not influenced by what happens in criminal court
  • You can appeal an unfavorable decision to a district court, but this is rare

Difference Between DMV Hearings and Court DUI Cases

It’s important to understand that DMV (MVD) hearings and DUI court cases are completely separate legal tracks.

MVD HearingCriminal DUI Case
Administrative, civil processCriminal court process
Handled by Montana MVDHandled by county or city court
Decides on license suspension onlyDecides on guilt, penalties, fines, jail
Triggered by BAC test or refusalTriggered by DUI charge
No juryMay involve jury trial
Short, focused hearingsFull legal proceedings

Even if you’re not convicted of DUI in criminal court, the MVD may still suspend your license based on the arrest and test results. Likewise, winning your MVD hearing doesn’t mean your court case will be dismissed.

What If You Don’t Request a Hearing?

If you don’t request a hearing within the 30-day deadline:

  • Your license will be automatically suspended
  • The suspension period will begin after the notice period ends
  • You lose the chance to contest the officer’s evidence
  • You may still face additional court-ordered suspensions later

This is why it’s important to understand the hearing process and act quickly if you want to challenge the license suspension. Missing the deadline has immediate and lasting consequences—even if your DUI case is resolved favorably in court.

Can You Get a Restricted or Probationary License?

Montana may allow drivers with suspended licenses to apply for a restricted license, sometimes called a probationary license. This license allows you to drive for specific purposes:

  • To and from work or school
  • For medical appointments
  • For court-ordered treatment or education programs

Whether you’re eligible depends on:

  • The nature of your offense
  • Whether this is a first or repeat DUI
  • Whether you refused the chemical test
  • Completion of alcohol education requirements

You typically must install an ignition interlock device in your vehicle before the restricted license is issued. This device requires a clean breath sample before the vehicle will start.

Frequently Asked Questions About MVD Hearings in Montana

Do I have to go to court and attend the MVD hearing?
Yes, both are separate. The MVD hearing is administrative and determines license status; the court hearing addresses the criminal DUI charge.

Can I skip the MVD hearing if I plan to fight the DUI in court?
You can skip it, but your license will be suspended automatically. Fighting the DUI in court does not affect the MVD suspension unless you win both.

What happens if I win the MVD hearing?
If the hearing officer rules in your favor, your license is not suspended. However, your DUI case in criminal court still proceeds.

Can I have a lawyer at the MVD hearing?
Yes. You may be represented by a lawyer, and it’s often helpful—especially if you plan to challenge the legality of the stop or test procedures.

Is the MVD hearing the same as a DUI trial?
No. The MVD hearing is only about your license status. It does not determine guilt or innocence for the DUI charge.

Conclusion

In Montana, the MVD hearing is a critical part of the DUI process. It runs separately from the criminal court case and focuses entirely on your driving privileges. After a DUI arrest, you only have a limited time—usually 30 days—to request this hearing. Failing to do so means losing your license by default.

Understanding how the MVD hearing works helps you prepare for this important administrative step and gives you the opportunity to challenge the suspension. While it won’t affect your court case directly, it can make a major difference in your ability to legally drive in the months ahead.

To learn more about the overall process from stop to sentencing, visit our full guide to the DUI process and timeline.

For a focused breakdown of license suspension and hearings, read our article on DMV hearings and license actions after a DUI arrest.

February 3, 2026 | LDUIL

How Long Does a DUI Case Take in Montana?

If you’ve been arrested for DUI in Montana, you may be wondering how long it will take for your case to be resolved. Is it a matter of weeks, months, or longer? The truth is: it depends. While some DUI cases move quickly through the system, others can stretch out over many months—especially if there are legal motions, negotiations, or a trial involved.

Montana’s DUI process follows a consistent set of steps, but the timeline varies depending on factors such as case complexity, court scheduling, and whether the defendant enters a plea or goes to trial. This article provides a clear overview of how long a typical DUI case takes in Montana, broken down by each phase in the process.

We’ll also cover the administrative side of things (such as license suspension) and look at how long-lasting the effects of a DUI charge can be—even after the court case ends. While this guide is not legal advice, it offers a structured, educational breakdown to help you understand the scope and timeline of a DUI case in Montana.

The Initial Arrest and Booking: 1 to 2 Days

Every DUI case in Montana starts with a traffic stop and arrest. If a law enforcement officer observes signs of impairment—such as erratic driving, slurred speech, or the smell of alcohol—they may conduct field sobriety tests or request a breathalyzer. If probable cause exists, the officer will arrest the driver.

After the arrest:

  • The driver is transported to jail or a detention facility
  • A chemical test (breath or blood) is typically administered
  • Booking procedures are completed
  • A temporary driver’s license suspension notice may be issued

In most cases, the person is released within 24 hours, either on bail, personal recognizance, or after sobering up. At this point, the legal process begins, and a court date is scheduled.

This initial phase is fast—but it sets in motion both the criminal court process and a separate administrative license action handled by the Montana Motor Vehicle Division (MVD).

Arraignment and First Court Appearance: 3 to 14 Days

The next step is the arraignment, also known as the initial appearance. This is usually scheduled within a few days to two weeks after the arrest, depending on the county court’s calendar and whether the person is held in custody.

At the arraignment:

  • The defendant hears the charges formally read
  • The judge advises the defendant of their rights
  • A plea is entered (typically “not guilty” at this stage)
  • Bail conditions or restrictions may be imposed
  • The court schedules the next hearing

Montana requires that DUI charges be addressed promptly in court, so this early appearance happens relatively quickly. Once it’s complete, the case enters the pretrial phase, which can vary widely in length.

Pretrial Phase and Case Preparation: 30 to 120 Days

The pretrial stage is often the longest phase of a DUI case. This is when both the prosecution and defense gather evidence, evaluate legal options, and possibly negotiate a resolution.

This phase typically lasts 1 to 4 months, and includes:

  • Discovery: Exchange of evidence, police reports, test results, and video footage
  • Motions: Legal filings to suppress evidence or challenge the arrest procedure
  • Pretrial Conferences: Meetings to discuss case progress, scheduling, and possible plea agreements
  • Negotiations: Prosecutors and defense attorneys may discuss reduced charges or sentencing alternatives

Some cases move quickly through this phase if the facts are straightforward and a plea deal is likely. Others may involve more complex legal issues that require time to resolve—especially if the defense plans to contest the charges.

Court calendars, attorney availability, and motions all affect how long the pretrial process takes in each DUI case in Montana.

Plea Bargain or Trial Decision: 60 to 180 Days

At some point during the pretrial phase, a decision must be made: accept a plea deal, or proceed to trial. This is a critical point in the DUI timeline, and it heavily influences how much longer the case will take.

  • Plea Deal Accepted: If a plea agreement is reached, the case can typically be resolved within 2 to 4 months from the arrest date
  • Trial Chosen: If the defendant pleads not guilty and no deal is accepted, the case proceeds to trial—usually scheduled 4 to 6 months out, depending on court backlog

Montana courts often schedule trial dates several months after the initial appearance, especially for DUI cases requiring a jury. This means the case may remain active for 6 months or more, particularly if the defense plans to present multiple witnesses or challenge evidence like the breath test.

DUI Trial and Verdict: 1 to 2 Days (Plus Wait Time)

If a DUI case goes to trial in Montana, the trial itself is relatively short—usually lasting 1 to 2 days. However, the wait time to reach the trial can stretch the case out for several months.

The trial phase includes:

  • Jury selection (if requested)
  • Opening arguments
  • Testimony from the arresting officer, experts, and witnesses
  • Cross-examination by the defense
  • Closing arguments and jury deliberation

Most DUI trials in Montana are completed in a day or two, especially if the case is straightforward. More complex trials may take longer, but that’s uncommon in DUI-only cases.

Once the trial concludes, the court issues a verdict: guilty or not guilty. If found guilty, the sentencing phase typically occurs shortly after.

Sentencing and Final Orders: 1 to 4 Weeks After Verdict or Plea

If the defendant is convicted—either by plea or trial—the case moves to sentencing. In many cases, sentencing occurs immediately after conviction, but in some instances it’s scheduled for a later date.

Montana DUI sentencing depends on:

  • Whether it’s a first, second, or third offense
  • The BAC level recorded
  • Whether a breath or blood test was refused
  • Any aggravating factors (accident, minor in vehicle, etc.)

A first-time DUI in Montana typically results in:

  • 24 hours to 6 months in jail (some of which may be suspended)
  • $600 to $1,000 in fines
  • 6-month license suspension
  • Mandatory alcohol education or treatment

After sentencing, the criminal court case is officially closed, although other consequences—such as license reinstatement—may still be pending.

Administrative License Suspension: 6 Months or More

Separate from the court process, Montana’s Motor Vehicle Division (MVD) handles administrative penalties—specifically license suspension.

These license actions can begin immediately after arrest:

  • Failed BAC Test (0.08% or higher): 6-month suspension
  • Refused Chemical Test: 6-month or 1-year suspension (depending on prior history)
  • MVD Hearing Option: Must be requested within 30 days of arrest

Even if the DUI charge is later reduced or dismissed in court, the administrative suspension may still stand.

In many cases, people complete their MVD suspension before their court case even ends, especially if the trial is delayed.

How Long Does a DUI Case Stay on Your Record?

While the court case itself may take only a few months, the impact of a DUI conviction lasts far longer. In Montana, DUI convictions stay on your criminal record permanently unless expunged—something that is difficult and rarely granted for DUI offenses.

Long-term timelines include:

  • Criminal Record: Indefinite unless sealed or expunged
  • Driver’s Record (MVD): DUI typically appears for 5 years or more
  • Insurance Increases: Can last 3 to 7 years, depending on your provider
  • Repeat Offense Window: Montana considers prior DUIs for 10 years when determining if a new offense is a repeat

These extended timelines are important to consider—even after the case is closed, the effects continue.

Frequently Asked Questions About DUI Case Timelines in Montana

How fast can a DUI case be resolved in Montana?
If there are no major issues and a plea is accepted early, a DUI case can be resolved in 6 to 8 weeks. However, most cases take 3 to 6 months.

Do I need to appear in court every time?
Usually yes—especially for arraignment, plea hearings, trial, and sentencing. Your attorney may attend some pretrial hearings on your behalf with court approval.

Can a DUI case be dismissed quickly?
It’s possible, but rare. Dismissals due to legal errors or evidence issues may happen early—but most cases proceed to plea or trial over several months.

How long will my license be suspended?
The administrative license suspension is typically 6 months for a first offense, starting shortly after arrest. Court-ordered suspensions may overlap or extend this.

What makes a DUI case take longer?
Delays in lab results, busy court schedules, contested motions, or choosing to go to trial can extend the timeline significantly.

Conclusion

In Montana, the timeline for a DUI case can vary from a few weeks to several months depending on the specifics of the arrest, the legal motions involved, and whether the case is resolved through a plea deal or trial. While most cases wrap up within 3 to 6 months, the administrative license suspension and long-term record consequences often last much longer.

Knowing what to expect during each phase of the DUI process can help you prepare for the road ahead—whether you’re facing charges or simply want to understand how the system works in Montana.

To explore how the court and DMV steps fit together, read our full guide on the DUI process and timeline.

For a closer look at the average duration of DUI cases, visit our post on how long a DUI case typically takes.

February 3, 2026 | LDUIL

Do You Have to Go to Court for a DUI in Montana?

If you’re arrested for DUI in Montana, one of the first questions that comes to mind is whether you have to appear in court. Many people hope that DUI charges can be resolved by paying a fine or attending a class without needing to go before a judge. However, in Montana, DUI charges are considered criminal offenses—not traffic violations—and court appearances are a mandatory part of the process.

Understanding when and why you must appear in court for a DUI is critical to managing the process effectively. Skipping a required appearance can lead to serious legal consequences, including arrest warrants and additional penalties. In this article, we’ll clarify exactly how court appearances work for DUI cases in Montana and explain each stage where the defendant is expected to show up.

This is an educational guide designed to explain the court process from a procedural standpoint—not legal advice. We’ll walk through each phase of a typical DUI case and answer the most common questions about court obligations.

Why DUI Charges Require a Court Appearance in Montana

Montana law treats DUI offenses as criminal charges—even for a first-time offender. That means they must be handled in a courtroom and judged by either a magistrate or jury, depending on the situation. Unlike civil infractions like speeding tickets or parking violations, DUI charges cannot be resolved online or by mail.

Key reasons DUI cases require court appearances:

  • They are criminal offenses, not civil matters
  • Penalties can include jail time, license suspension, and fines
  • The court must hear a formal plea
  • Judicial oversight is required for sentencing and case resolution

If you’re charged with DUI in Montana, you are expected to appear in court for several required proceedings, beginning with your arraignment.

First Mandatory Appearance: Arraignment

The first official court appearance in a DUI case is called an arraignment. This usually takes place within a few days of arrest or upon receiving a summons. At this hearing, the defendant is formally read the charges and asked to enter a plea.

What happens at the arraignment:

  • The judge reviews the charges on the record
  • You are advised of your legal rights
  • A plea of guilty, not guilty, or no contest is entered
  • Bail conditions may be reviewed or modified
  • A trial or pretrial date is scheduled

This appearance is mandatory. Failing to appear can result in a bench warrant being issued for your arrest, additional charges, and forfeiture of bail. In Montana, a first-time DUI charge is generally a misdemeanor, but even misdemeanor cases require formal court appearances.

Do You Need to Attend Every Hearing?

In most DUI cases, you will be required to attend multiple hearings unless the court specifically excuses your presence. The number of hearings depends on how the case progresses, whether you accept a plea deal, or whether it proceeds to trial.

Types of court appearances that may require your attendance:

  • Initial Appearance / Arraignment (always required)
  • Pretrial Conferences (usually required)
  • Motion Hearings (may be required depending on the issue)
  • Trial (always required if held)
  • Sentencing Hearing (required if convicted or plea is entered)

In some situations—especially if you’re represented by an attorney—the court may waive your appearance for certain administrative hearings. But this is only possible with prior approval. Otherwise, personal appearance is the default expectation in Montana DUI cases.

What Happens If You Miss a DUI Court Appearance?

Missing a required DUI court date is a serious matter in Montana. Courts expect full compliance with scheduled appearances, and failing to show up can trigger immediate legal consequences.

What may happen if you miss a court date:

  • Bench Warrant Issued: A judge can issue a warrant for your arrest
  • Bail Revoked: If you posted bail, it may be forfeited
  • Additional Charges: You could be charged with “failure to appear,” a separate offense
  • Driver’s License Consequences: Courts often notify the MVD, which may initiate further suspension or restriction

Once a warrant is issued, law enforcement may locate and arrest you at home, work, or during any other encounter—potentially making your legal situation worse than the original DUI charge.

Can an Attorney Appear on Your Behalf?

In certain stages of a DUI case, a licensed defense attorney may be allowed to appear in court on your behalf. This is more common in misdemeanor DUI cases where no jail time is immediately expected and the defendant complies with all conditions.

Typical scenarios where attorney-only appearances may be allowed:

  • Pretrial status hearings
  • Scheduling conferences
  • Document review hearings
  • Court-approved waivers of appearance

However, you will still be required to appear personally for:

  • Arraignment (unless waived in advance)
  • Plea hearings
  • Trials
  • Sentencing hearings

Judges in Montana generally prefer defendants to be present, especially for key proceedings. Attorney-only appearances must be specifically approved by the court and are not guaranteed.

Court Appearance Requirements for Out-of-State Drivers

If you’re an out-of-state driver arrested for DUI in Montana, you are still subject to Montana’s court rules. You must appear in court just like a Montana resident unless special arrangements are made through an attorney.

Here’s how it typically works:

  • You’ll receive a court date listed on your summons or release paperwork
  • If you retain a Montana-based attorney, they may file a motion to excuse your appearance at certain hearings
  • You must still appear for arraignment, plea, trial, and sentencing unless formally excused
  • Failure to appear can lead to a warrant and notification to your home state’s DMV

Ignoring the case because you live elsewhere will not make it go away. Montana shares driver information with other states, and a DUI case will follow you until resolved.

Does a DUI Court Appearance Mean You’re Guilty?

No. Appearing in court for a DUI charge in Montana does not mean you’re guilty. Court appearances are part of the legal process that allows the charges to be reviewed, challenged, or resolved.

A court appearance is your opportunity to:

  • Enter a plea
  • Request discovery of evidence
  • File legal motions
  • Negotiate with the prosecutor
  • Prepare for trial if needed

Montana’s legal system is built on the presumption of innocence. Until convicted, you have the right to challenge the evidence and the circumstances of your arrest.

It’s also worth noting that many DUI cases are resolved without trial, either through plea deals or dismissal of charges when legal flaws are discovered.

Frequently Asked Questions About DUI Court Appearances in Montana

Do I have to appear in court for a first-time DUI?
Yes. Even first-time DUI charges in Montana require one or more court appearances because they are criminal offenses.

Can I just pay a fine instead of going to court?
No. DUI charges cannot be resolved by paying a fine outside of court. A judge must approve any penalties, even as part of a plea.

What if I live in another state?
You are still required to appear in Montana court unless a judge grants an exception. A local attorney can help request limited appearances.

What happens if I miss a court date?
A bench warrant may be issued for your arrest, and you may face additional penalties or license consequences.

Can my attorney go to court for me?
Sometimes. For certain non-critical hearings, your attorney may appear without you—but this must be approved in advance by the court.

Conclusion

In Montana, a DUI charge requires you to appear in court. This is true whether it’s your first offense or not, and regardless of where you live. The court process includes arraignment, possible pretrial hearings, plea discussions, and potentially a trial. Missing a court appearance can escalate the situation quickly, leading to a warrant and further penalties.

Understanding the DUI court timeline and your obligations helps you navigate the system more confidently. While certain appearances may be handled by your attorney, showing up when required is essential to resolving the charge properly.

For a full look at how DUI cases unfold from the roadside stop to court, read our breakdown of the DUI process from traffic stop to court.

To explore the full scope of the Montana legal process, see our main guide on the DUI process and timeline.

February 3, 2026 | LDUIL

What Is the DUI Court Process in Montana?

If you’re facing a DUI charge in Montana, one of the first questions you’ll likely have is: what happens next? The court process can feel confusing, especially if you’ve never been involved with the legal system before. Montana’s DUI court process follows a series of steps that begin shortly after arrest and may continue for several months, depending on how the case unfolds.

Understanding this process doesn’t just help you know what to expect—it also helps you make sense of the paperwork, court appearances, and procedures that follow. While this guide does not provide legal advice, it offers a complete overview of how DUI cases move from arrest to resolution within the Montana court system.

In this post, we’ll walk through each major phase of the DUI court process in Montana. From the initial arrest through arraignment, pretrial motions, potential plea deals, and trial, you’ll get a clear sense of how the state handles these cases and what each step involves.

Step 1: The DUI Arrest and Immediate Aftermath

The DUI court process begins at the moment of arrest. In Montana, officers typically initiate a traffic stop after observing suspicious driving behavior or a violation such as swerving, speeding, or running a stop sign. If impairment is suspected, officers may perform field sobriety tests or a breath test.

If probable cause is found, the driver is arrested and taken to a local jail or detention center. At this point, several things happen quickly:

  • The vehicle may be towed or impounded
  • A chemical test (breath or blood) may be administered
  • Booking procedures begin (photograph, fingerprints, personal details)
  • A Notice of Suspension may be issued for the driver’s license
  • The driver may be held in custody until bail is posted or a release is granted

The arrest itself sets in motion both an administrative process (usually involving license suspension) and a criminal process that begins in court.

Step 2: Initial Court Appearance and Arraignment

The first official court proceeding after a DUI arrest in Montana is the initial appearance, also known as the arraignment. This usually occurs within a few days of the arrest, especially if the person remains in custody.

During this hearing, the following occurs:

  • The judge informs the defendant of the charges
  • The defendant is advised of their rights
  • A plea is entered (usually “not guilty” at this stage)
  • Bail conditions may be reviewed or set
  • A future court date is scheduled

The arraignment is typically brief, but it’s an important step that marks the formal start of the court case. At this point, the case becomes part of the public court docket, and the legal process begins to unfold in earnest.

In Montana, most first-time DUI offenses are filed as misdemeanors, but aggravating factors can elevate the charge to a felony. Either way, the case moves through the appropriate court with its own calendar and deadlines.

Step 3: Pretrial Motions and Evidence Review

Once the arraignment is complete, the pretrial phase begins. This is where both the prosecution and defense prepare their cases. A large part of this phase involves discovery, where each side exchanges evidence and information.

Key elements of the pretrial phase in Montana include:

  • Discovery Requests: The defense may request police reports, body camera footage, chemical test results, calibration records, and more
  • Motions to Suppress: The defense may challenge the legality of the traffic stop, the arrest, or the chemical test procedure
  • Motion Hearings: A judge may hear arguments about excluding evidence, challenging probable cause, or modifying bail conditions
  • Negotiations: In some cases, the prosecution may offer a plea deal in exchange for a guilty plea to a reduced charge

This stage is also when the defense might request independent testing of blood samples or further analysis of breath test devices. Any errors in procedure or lapses in protocol discovered here can significantly affect the outcome of the case.

Step 4: Plea Bargains and Alternative Resolutions

Not every DUI case in Montana goes to trial. In fact, many are resolved through plea agreements during the pretrial phase. A plea bargain is an agreement between the defendant and prosecutor in which the defendant pleads guilty—usually to a lesser charge or with agreed-upon sentencing terms.

Common plea deal outcomes might include:

  • Reduction of a DUI charge to reckless driving or another non-alcohol-related offense
  • Agreement to participate in alcohol treatment or education programs
  • Lower fines or reduced jail time
  • No contest plea with agreed sentencing terms

Whether a plea deal is offered depends on multiple factors, including:

  • The strength of the evidence
  • Whether the defendant has prior DUI convictions
  • The specific circumstances of the arrest
  • Prosecutorial discretion

Plea bargains can resolve a case more quickly and with more predictable outcomes, but they are not guaranteed and are evaluated case by case.

Step 5: DUI Trial Process in Montana

If no plea deal is reached, the case proceeds to trial. DUI trials in Montana are typically held in city or county courts, and the defendant can choose a jury trial or bench trial (where a judge decides the outcome).

The trial process includes:

  • Jury Selection (if applicable)
  • Opening Statements from both sides
  • Presentation of Evidence by the prosecution (including officer testimony, test results, body cam footage, etc.)
  • Cross-Examination by the defense
  • Defense Case (if presented)
  • Closing Arguments
  • Verdict: The judge or jury decides if the defendant is guilty or not guilty

If convicted, sentencing is usually scheduled shortly after. If acquitted, the case is dismissed, and no criminal penalties apply (though administrative penalties like license suspension may still be in place).

Trials are rare for first-time DUI charges but are more common in complex or contested cases.

Step 6: Sentencing and Penalties if Convicted

If the court finds the defendant guilty, either through plea or trial, sentencing follows. In Montana, penalties for DUI vary based on whether it is a first, second, or subsequent offense. Factors like BAC level, refusal to test, or the presence of minors in the vehicle can also influence sentencing.

Typical penalties for a first-time DUI conviction in Montana include:

  • Jail Time: 24 hours to 6 months
  • Fines: $600 to $1,000
  • License Suspension: Usually 6 months
  • Mandatory Alcohol Education or Treatment
  • Possible Ignition Interlock Device Installation

Repeat offenses result in harsher penalties, including longer jail time, higher fines, and extended license revocation periods.

The sentencing phase also considers whether the defendant has completed any pretrial requirements or enrolled in alcohol education programs, which may influence outcomes.

Step 7: Post-Conviction Consequences and License Reinstatement

After sentencing, the court process ends, but the consequences may continue. Many DUI convictions in Montana carry long-term impacts, especially for driving privileges and background records.

Post-conviction outcomes may include:

  • Loss of Driving Privileges: Extended license suspension or revocation
  • Insurance Increases: Higher auto premiums or policy cancellations
  • Permanent Criminal Record: DUI convictions remain on public records and can appear in background checks
  • Ignition Interlock Requirements: Mandatory device installation as a condition of license reinstatement
  • Probation Monitoring: Some sentences include supervised probation, especially for repeat offenders

Reinstating a driver’s license after suspension requires completing all court-ordered conditions, paying fees, and in some cases, retaking driving tests. The Montana Motor Vehicle Division handles this process separately from the court system.

Frequently Asked Questions About the DUI Court Process in Montana

How long does the DUI court process take in Montana?
A simple case may resolve in a few weeks if a plea deal is accepted. Contested cases that go to trial can take several months or longer.

Can a DUI charge be dismissed?
Yes, but it’s rare. Charges may be dropped due to lack of evidence, procedural errors, or successful legal motions.

Do I have to appear in court for a DUI in Montana?
Yes. DUI charges require one or more court appearances. Failing to appear can lead to a warrant for arrest.

Will I lose my license automatically after arrest?
Not automatically—but a failed or refused chemical test usually triggers an administrative suspension by the MVD, even before conviction.

What happens if I refuse a breath test?
Refusal can lead to longer license suspension and may still result in criminal charges if impairment is suspected.

Conclusion

The DUI court process in Montana follows a clear but multi-step path. After the arrest, drivers move through arraignment, pretrial motions, possible plea negotiations, and—if necessary—trial and sentencing. Along the way, the state evaluates evidence, enforces administrative penalties, and determines whether a conviction will follow.

Understanding this process helps make sense of what to expect after a DUI arrest and how cases move through the Montana legal system.

For a complete breakdown of the entire DUI timeline from arrest to resolution, visit our article on the DUI process from traffic stop to court.

To explore how DUI cases are handled overall, including administrative and legal steps, read our guide on DUI process and timeline.

February 3, 2026 | LDUIL

Can DUI Charges Be Dropped in Montana?

Getting charged with DUI in Montana can feel like a permanent mark on your record—but it’s important to understand that a charge is not the same as a conviction. While Montana takes impaired driving seriously, not every DUI charge leads to penalties. In some cases, DUI charges can be reduced or even dropped, depending on the circumstances of the arrest and the legal process that follows.

So, what are the chances of a DUI charge being dropped in Montana? And under what conditions might that happen?

This article explores the rare but possible scenarios in which DUI charges may be dismissed. It outlines the legal process, what prosecutors consider, and the role of evidence in determining whether a case proceeds. While outcomes vary, understanding how the system works can clarify what’s possible—and what’s not—after a DUI charge is filed.

This is not legal advice, but an informational breakdown of how DUI charges move through Montana’s legal system, and when edge-case outcomes like dismissal might occur.

What It Means to Have a DUI Charge Dropped

In Montana, a DUI charge is “dropped” when the prosecutor decides not to pursue the case, or when a court dismisses it before trial. This can happen during early hearings, pretrial negotiations, or in rare situations, just before trial begins.

Dismissals can occur for several reasons:

  • Insufficient evidence to proceed
  • Procedural errors in the arrest
  • Violations of the driver’s rights
  • Problems with the chemical test results
  • Officer misconduct or credibility issues
  • Agreement to a plea deal involving a different, lesser charge

It’s important to distinguish between a case being dropped and being found not guilty at trial. A dropped charge ends the legal process before trial; a not guilty verdict comes after the case is heard in court.

In either situation, the person avoids a DUI conviction—but the legal path is different.

The Role of the Prosecutor in Dropping DUI Charges

In Montana, prosecutors have wide discretion when deciding whether to pursue DUI charges. After reviewing the arrest report, test results, and any supporting documents, the prosecutor evaluates the case’s strength.

If there are serious weaknesses, the prosecutor may:

  • Choose not to file charges at all
  • File a reduced charge (e.g., reckless driving)
  • File DUI charges and later dismiss them if problems emerge

Reasons a prosecutor might drop DUI charges include:

  • Missing or invalid chemical test results
  • Conflicting or unreliable officer reports
  • A traffic stop that lacked probable cause
  • Witness statements that undermine the case
  • Technical issues with breathalyzer calibration or chain of custody

However, prosecutors are under pressure to enforce DUI laws strongly. They generally pursue charges unless there’s a clear issue that prevents a successful conviction.

Evidence Issues That Can Lead to Dismissal

In DUI cases, the strength of the evidence is key. If critical evidence is missing or flawed, the prosecutor may not be able to prove the case beyond a reasonable doubt. This is often where DUI charges may be dropped.

Examples of evidence problems that may lead to dismissal:

  • Invalid Traffic Stop: If the officer lacked legal grounds to pull over the driver, any evidence gathered after the stop could be suppressed.
  • Breath Test Malfunction: If the breathalyzer wasn’t properly maintained, or records show calibration errors, the results may not be usable.
  • Blood Test Issues: Problems with how a blood sample was stored, transported, or tested could call the results into question.
  • Body Camera Footage: Video evidence that contradicts the arrest report or shows improper procedure can cast doubt on the officer’s account.
  • Inconsistent Testimony: If the officer gives conflicting statements, their credibility may be challenged.

Montana courts typically require that DUI cases rest on a solid foundation of both observation and chemical testing. If either is compromised, the entire case may weaken to the point of dismissal.

Motion to Suppress: A Common Path to Dismissal

One way DUI charges can be dropped is through a motion to suppress evidence. This is a legal request made by the defense to exclude certain evidence from the trial.

Common suppression arguments in Montana DUI cases include:

  • Illegal stop or search: The officer pulled over the driver without a legal reason
  • Improper testing procedure: The chemical test was conducted incorrectly
  • Violation of Miranda rights: The driver was questioned without proper advisement
  • Lack of probable cause for arrest: The officer didn’t have enough reason to make the arrest

If a judge grants the motion and key evidence is excluded, the prosecutor may have no case left. In these situations, charges are often dropped voluntarily by the prosecution.

It’s worth noting that motions to suppress are complex and not always successful. However, they are a recognized legal tool that can shift the outcome of a case—especially when clear procedural errors are present.

When Charges Are Reduced Instead of Dropped

Sometimes, DUI charges are not dropped entirely but are reduced to a lesser charge. This is common in Montana for first-time offenders or when the BAC was close to the legal limit.

A reduced charge might include:

  • Reckless driving
  • Negligent driving
  • Disorderly conduct related to vehicle use
  • Careless driving, if impairment is not clearly proven

Reduced charges generally come with lower fines, no jail time, and fewer long-term consequences. They may also avoid some of the license suspension penalties tied to DUI convictions.

These outcomes often happen through plea agreements, where the defendant agrees to certain conditions (e.g., treatment, fines) in exchange for a downgraded charge.

Factors That Decrease the Chances of Charges Being Dropped

While DUI charges can be dropped, most are not. Several factors make it less likely:

  • High BAC: Readings significantly over 0.08% leave less room for doubt
  • Repeat Offenses: Prosecutors are less willing to negotiate with repeat offenders
  • Accidents or Injuries: If a DUI caused harm or property damage, prosecutors are unlikely to dismiss charges
  • Test Refusal: Refusing chemical tests limits evidence challenges and may harden the prosecution’s approach
  • Video Evidence: If body camera or dashcam footage supports the arrest, it strengthens the case

Montana courts prioritize road safety and expect prosecutors to pursue DUI cases unless there are compelling reasons not to.

Impact of a Dismissal on Driving Records and Public Records

If DUI charges are dropped, that outcome is better than a conviction—but it doesn’t necessarily mean the incident disappears entirely.

  • Arrest Records: The arrest may still appear on background checks unless formally expunged
  • Public Court Records: The case file may show that DUI charges were filed, then dismissed
  • License Suspension: The administrative suspension by the MVD may still stand, even if criminal charges are dropped
  • Insurance: Some insurance companies may still increase rates based on the arrest alone

In Montana, record sealing or expungement of DUI-related charges is limited and not automatic. Anyone with dropped charges may need to petition separately for record relief.

Frequently Asked Questions About DUI Charges Being Dropped in Montana

How often are DUI charges dropped in Montana?
Rarely. While it’s possible, most DUI cases proceed to prosecution unless clear issues with evidence or procedure exist.

Can I request that my DUI charges be dropped?
Only the prosecutor or the court can drop charges. A defendant may request consideration, but the final decision lies with the state.

Does dropping charges mean my record is clean?
Not necessarily. The arrest and court filing may still appear on your record unless formally sealed or expunged.

Will my license suspension be lifted if charges are dropped?
Not always. The administrative license suspension by the MVD is a separate process and may still apply.

Can charges be dropped after a plea deal?
Yes. In many cases, prosecutors agree to drop DUI charges in exchange for a guilty plea to a lesser offense.

Conclusion

DUI charges in Montana are serious, but they are not set in stone. In limited cases, charges can be dropped due to legal errors, weak evidence, or procedural issues. However, this is the exception, not the rule. Most DUI cases proceed unless a clear problem undermines the prosecution’s ability to prove impairment.

Understanding how charges are filed and prosecuted—and when they might be dismissed—gives you a more complete picture of the legal landscape. Whether the issue is with chemical testing, officer procedures, or the legality of the stop, Montana law provides pathways for cases to be challenged when errors occur.

To learn how these cases move through the system, read our detailed explanation of how DUI laws work.

For insight into how the prosecution files and handles these charges, visit our article on how DUI charges are filed and prosecuted.

February 3, 2026 | LDUIL

What Happens After a DUI Arrest in Montana?

A DUI arrest can feel confusing and overwhelming. While the event itself may only take a few minutes, what happens afterward unfolds over days, weeks, and even months. In Montana, a DUI arrest triggers a series of legal and administrative steps that determine what penalties may follow, how your license is affected, and whether charges will result in a conviction.

This post walks through the process that follows a DUI arrest in Montana—from what occurs immediately at the scene to the legal filings, hearings, and possible outcomes. If you’re trying to understand what actually happens after someone is taken into custody for DUI in Montana, this guide explains each phase of the process clearly and in order.

The goal is to break down the timeline and procedures into understandable pieces. We won’t cover legal advice, but we will explain what to expect, what the state does next, and how DUI charges move forward through Montana’s system.

Immediate Actions After a DUI Arrest in Montana

Once law enforcement makes the decision to arrest a driver for DUI, the process moves quickly. The first steps typically occur at the scene or shortly after:

  • Transport to Jail or Detention Center: The driver is usually taken to a local jail or holding facility for booking.
  • Search and Inventory: The vehicle may be searched and towed, and personal belongings are inventoried during the booking process.
  • Chemical Testing: If a breath test wasn’t performed roadside, a follow-up breath or blood test may be administered at the jail.
  • Booking: The driver’s personal information is logged, fingerprints are taken, and the arrest is formally recorded.
  • Temporary License Suspension: If the driver failed or refused a chemical test, the Montana Department of Motor Vehicles (DMV) is notified, and a temporary license suspension may go into effect.

At this point, no formal criminal charges have been filed in court, but the arrest and test results set everything in motion. A key detail here is that Montana separates administrative actions (like license suspension) from criminal proceedings, even though they’re both related to the same arrest.

Administrative License Suspension Process

One of the first consequences a driver may face after a DUI arrest in Montana is the administrative suspension of their driver’s license. This action is taken by the state’s Motor Vehicle Division (MVD), not a court.

The suspension process generally works like this:

  • Failed BAC Test (0.08% or higher): Automatic 6-month license suspension
  • Test Refusal: Longer suspension—usually 6 months for a first offense and 1 year for repeat offenses
  • Notice of Suspension: Officers often issue a Notice of Suspension at the time of arrest
  • Temporary Driving Permit: Drivers may be given a 5–10 day temporary permit to allow time to request a hearing

Drivers have the right to challenge the administrative suspension by requesting a MVD hearing within a short time frame—usually 30 days. This hearing is separate from the criminal trial and focuses only on the legality of the stop, the arrest, and the chemical test procedures.

Even if a person is later found not guilty in criminal court, the administrative suspension can still stand if the MVD upholds the original enforcement.

Filing of Criminal Charges in Montana Courts

After the arrest and administrative actions begin, the criminal case moves forward. In Montana, prosecutors typically file DUI charges based on the arrest report, chemical test results, and officer observations. The criminal process begins with:

  • Charging Decision: The county or city prosecutor reviews the evidence and formally files charges
  • Initial Appearance / Arraignment: The driver appears before a judge, usually within a few days, to hear the charges and enter a plea
  • Conditions of Release: The judge may impose conditions such as alcohol monitoring, travel restrictions, or pretrial check-ins

At this stage, DUI is treated as a criminal offense, not just a traffic violation. A first-time DUI is usually a misdemeanor, but certain factors (e.g., high BAC, injury, prior offenses) may elevate it to a felony.

Montana law allows for enhancements based on:

  • Previous DUI convictions within the past 10 years
  • Whether the DUI involved a crash or injury
  • Whether there was a minor in the vehicle
  • Refusal to comply with chemical testing

These factors will shape how the prosecutor approaches the case and what penalties may be sought.

The Pretrial Phase: Motions and Negotiations

After the charges are filed and the case is officially in court, the next phase is pretrial preparation. This stage may last weeks or months, depending on the complexity of the case. Several key steps happen here:

  • Discovery: Both sides exchange evidence, including police reports, body camera footage, chemical test data, and witness statements
  • Motions: Attorneys may file motions to suppress certain evidence, request changes to pretrial conditions, or challenge the validity of the arrest
  • Negotiations: In many cases, the prosecution and defense engage in plea negotiations to resolve the case without trial

Montana courts may offer plea agreements for reduced charges or lighter sentencing under specific conditions—especially for first-time offenses. Whether this occurs depends on the case facts and the approach of the prosecutor.

In some cases, defendants choose to proceed to trial, especially if there are contested facts, concerns about test accuracy, or questions about how the stop occurred.

Criminal Trial and Court Proceedings

If the DUI case is not resolved through a plea deal, it moves to trial. DUI trials in Montana are typically held in a city or county court and may be heard by a judge or jury, depending on the defendant’s choice.

Here’s what happens during the trial phase:

  • Opening Statements: Both sides present their basic case to the judge or jury
  • Prosecution Evidence: The state calls witnesses such as the arresting officer, toxicology experts, or others involved
  • Defense Response: The defense can cross-examine witnesses and present evidence or testimony
  • Closing Arguments: Both sides summarize their position
  • Verdict: The judge or jury decides whether the defendant is guilty or not guilty

If the driver is convicted, sentencing usually follows quickly. If they are acquitted, the case ends and no criminal penalties are applied. However, administrative consequences (like license suspension) may still remain in place.

Sentencing and Penalties for DUI Convictions in Montana

Sentencing for a DUI conviction in Montana depends on whether it is a first-time or repeat offense, and whether there were any aggravating factors. Typical penalties for a first offense include:

  • Jail Time: Minimum 24 hours up to 6 months
  • Fines: Between $600 and $1,000
  • License Suspension: 6-month suspension
  • Mandatory Alcohol Education or Treatment Program
  • Possible Ignition Interlock Requirement

For second and third offenses, penalties increase significantly:

  • Longer jail terms
  • Higher fines
  • Longer license suspension or revocation
  • Mandatory installation of an ignition interlock device

A fourth or subsequent DUI may be charged as a felony, with extended prison time and long-term loss of driving privileges.

Montana law also imposes additional fees and assessments, including court costs, DUI surcharges, and MVD reinstatement fees.

Long-Term Consequences After a DUI Conviction

The impact of a DUI arrest doesn’t end with sentencing. In Montana, a DUI conviction can have long-term effects that extend into many areas of life, including:

  • Employment: Some employers may conduct background checks and be concerned about criminal records
  • Insurance: Auto insurance premiums may rise dramatically or coverage may be dropped altogether
  • Professional Licenses: Certain professions require reporting of convictions, which can affect licensing or employment status
  • Travel: Some countries restrict entry for individuals with DUI convictions
  • Public Records: The conviction becomes part of your permanent record unless expunged (which is not easy or guaranteed)

For many people, these indirect consequences are just as significant as the court-ordered penalties, especially when applying for jobs, housing, or school programs in the future.

Frequently Asked Questions About What Happens After a DUI Arrest in Montana

How long does the DUI process take in Montana?
It varies. Simple cases may resolve in a few weeks, while others—especially with motions or trial—can take several months.

Can I drive after a DUI arrest?
You may be eligible for a temporary driving permit for a short time. If your license is suspended, restricted driving privileges might be available under certain conditions.

Is a DUI in Montana a felony?
Usually no—most first and second DUIs are misdemeanors. However, a fourth offense or a DUI involving serious injury can be charged as a felony.

Do I need to appear in court?
Yes. A DUI charge requires court appearances. Failure to appear can result in additional charges and arrest warrants.

Can I get the charge dismissed?
Dismissals are possible but rare. They usually require legal grounds such as lack of probable cause or problems with the chemical test procedure.

Conclusion

After a DUI arrest in Montana, the legal process unfolds in several distinct phases: immediate consequences, administrative license actions, criminal charges, pretrial hearings, and potential sentencing. Whether it’s your first arrest or a repeat offense, the steps are structured and predictable—though the outcomes vary depending on the facts of each case.

Understanding how DUI charges are filed and move through the court system can help you see the full picture. From the moment of arrest to potential long-term impacts, Montana law applies a multi-layered process to every DUI case.

For a full breakdown of the legal structure behind these events, explore our explanation of how DUI laws work.

To see how cases proceed after arrest, visit our article on how DUI charges are filed and prosecuted.

February 3, 2026 | LDUIL

Can You Be Arrested for DUI Without Failing a Breath Test in Montana?

Many drivers in Montana assume that a DUI arrest can only happen if they fail a breathalyzer test. After all, if a breath test shows your blood alcohol concentration (BAC) is below the legal limit, shouldn’t that mean you’re safe from arrest? Not quite. In Montana, like in many states, officers can arrest someone for driving under the influence (DUI) based on more than just the results of a breath test.

This article breaks down the reality of DUI enforcement in Montana. It explains how a person can be arrested even without a failed breath test—or sometimes without taking a breath test at all. Officers are trained to look at the full context of a traffic stop, not just the BAC number. Observations, field tests, driving behavior, and even driver statements all contribute to whether a DUI arrest is made.

We’ll explore how Montana’s DUI laws work in practice, what role breath testing really plays, and why it’s entirely possible to be arrested even if your BAC is under 0.08%. By the end, you’ll understand the full scope of how DUI arrests are triggered in the state.

What Montana Law Says About DUI Arrests

Montana law defines DUI as operating a motor vehicle while under the influence of alcohol, drugs, or any combination of substances that impair a person’s ability to safely drive. While a BAC of 0.08% or more for drivers aged 21 and older is considered automatic grounds for a DUI charge, the law also allows officers to arrest drivers they believe are impaired—even if that BAC threshold isn’t met.

Montana’s DUI laws are written to cover more than just measurable intoxication. They account for observed impairment, physical behavior, and driver conduct. This means that if an officer believes a person is unable to safely operate a vehicle due to alcohol or drug use, an arrest can be made even in the absence of a failed breath test.

In other words, the presence of impairment—not just a BAC reading—is what triggers the legal process. This flexible approach gives law enforcement room to make decisions based on the entire situation, not a single test result.

Officer Observations and Driving Behavior

DUI investigations in Montana often start with a traffic stop. Officers are trained to watch for signs of unsafe or erratic driving behavior that could indicate impairment. Common triggers for a stop include:

  • Weaving or drifting between lanes
  • Sudden braking or acceleration
  • Ignoring traffic signs or signals
  • Driving far below or above the speed limit
  • Making unusually wide or abrupt turns

Once a driver is pulled over, officers use their senses and training to assess the person’s condition. They’re looking for things like:

  • Slurred or delayed speech
  • The smell of alcohol or drugs in the vehicle
  • Red or glassy eyes
  • Slow response to questions
  • Fumbling for a license or registration

None of these signs, on their own, prove that a person is impaired. But combined, they may suggest that a driver is not in full control. In such cases, the officer may begin a full DUI investigation—even before asking for a breath test.

Field Sobriety Tests as a Primary Indicator

Field sobriety tests (FSTs) play a central role in DUI investigations where breath tests are absent or inconclusive. In Montana, these roadside evaluations help officers determine if a driver’s physical and mental faculties are impaired.

Common FSTs include:

  • Horizontal Gaze Nystagmus (HGN): The officer checks for involuntary eye movement while the driver follows a moving object, like a pen or flashlight.
  • Walk-and-Turn Test: The driver is instructed to take nine heel-to-toe steps in a straight line, turn on one foot, and return in the same way.
  • One-Leg Stand: The driver must stand on one leg while counting aloud for 30 seconds without swaying or using arms for balance.

These tests are designed to detect impairment through balance, coordination, and the ability to follow instructions—all of which may be affected by alcohol or drug use.

It’s important to note that Montana law does not require drivers to perform these tests, and refusal is allowed. However, declining them doesn’t stop a DUI investigation. Officers can still proceed based on other observations, and refusal may be noted as a sign of non-compliance.

Breath Tests: Important, But Not Always Central

Breath tests are commonly used in DUI cases, but they are not the only tool officers rely on. In Montana, a breath test may not be administered at all under certain circumstances, or it may yield results under the legal limit—yet a DUI arrest can still occur.

Here are several examples where breath tests are not the final factor:

  • BAC Under 0.08%: A driver may blow a 0.05% or 0.06% but still be showing strong signs of impairment. If so, the officer can arrest them based on their behavior, speech, and performance on field sobriety tests.
  • Drug Impairment: Breath tests detect alcohol, not drugs. A person impaired by marijuana, prescription medication, or other substances may have a BAC of 0.00%, but still be unfit to drive.
  • Equipment Malfunction or Unavailability: If a breathalyzer isn’t working properly or not available at the scene, officers can still make an arrest based on everything else they observe.
  • Test Refusal: If the driver refuses the breath test, that refusal may result in an automatic license suspension—and does not prevent the officer from making an arrest based on probable cause.

In all of these situations, Montana law supports the officer’s discretion to proceed with an arrest if they reasonably believe the driver is impaired.

Understanding Probable Cause in DUI Arrests

The legal standard that justifies a DUI arrest is “probable cause.” This means an officer must have enough evidence or reasonable belief that a person is driving while impaired. Probable cause does not require hard proof—it requires reasonable grounds based on facts and observations.

Officers establish probable cause using:

  • The driver’s behavior before the stop
  • Speech, appearance, and coordination
  • Statements made by the driver
  • Results from field sobriety tests
  • Evidence in the vehicle (open containers, drug paraphernalia)
  • Breath test results, if available

Montana officers are trained to follow a checklist-based approach, using documentation and detailed reports to support their decisions. Breath tests are part of this equation, but not the only factor. As long as the total evidence supports the officer’s belief that a DUI has occurred, an arrest may be made.

Refusing a Breath Test in Montana

Montana is an implied consent state. This means that by driving on public roads, you automatically consent to BAC testing if an officer has lawfully requested it. Refusing a breath test can lead to consequences separate from a DUI charge, including:

  • Automatic license suspension (usually 6 months for a first refusal)
  • Possible loss of restricted driving privileges
  • Use of refusal as evidence of impairment in court

Many drivers mistakenly believe that refusing the test will help them avoid a DUI charge. In practice, refusal rarely protects a person from being arrested. Officers are still permitted to make the arrest and may proceed with a blood test, especially if a warrant is obtained.

Refusing a test can actually make things worse, because it limits the driver’s ability to challenge the case based on the results.

Drug-Related DUI Arrests Without Breath Testing

Montana’s DUI laws cover both alcohol and drugs. When drugs are involved, breath tests are ineffective. In these cases, DUI arrests are made based on:

  • Officer observations of impairment
  • Field sobriety test performance
  • Admittance of drug use by the driver
  • Presence of substances or paraphernalia in the vehicle

Blood tests may be used after arrest to confirm drug presence, but the arrest itself can happen based on the signs of impairment alone. Montana law does not require chemical confirmation before an arrest is made.

This is especially relevant as marijuana use becomes more common. Even legal use of cannabis can result in DUI charges if a person is impaired behind the wheel.

DUI Arrests at Accident Scenes

Another common situation where breath tests may not be central is during or after a vehicle accident. If officers arrive at a crash site and suspect one of the drivers is impaired, they may begin a DUI investigation based on:

  • Eyewitness accounts
  • Smell of alcohol
  • Driver behavior at the scene
  • Statements made during questioning
  • Physical evidence in the vehicle

Sometimes the driver may be injured or unable to perform a breath test at the scene. In such cases, officers may proceed with an arrest and request a blood test later. The arrest is still considered valid if the signs of impairment are clear and documented.

Frequently Asked Questions About DUI Arrests Without a Failed Breath Test in Montana

Can I still be arrested if my BAC is below 0.08%?
Yes. Montana law allows for DUI arrests if impairment is observed, even if the BAC is under 0.08%.

What if I refuse the breath test?
Refusal leads to an automatic license suspension and does not prevent the officer from arresting you based on other evidence.

Do I have to take field sobriety tests?
No. Field sobriety tests are voluntary. However, refusing them may still be noted in the officer’s report and can affect the arrest decision.

Can I be arrested for DUI if I’m on legal medication?
Yes. If the medication impairs your ability to drive safely, a DUI arrest may be made—even if the medication is legally prescribed.

Is it legal to arrest someone without a chemical test result?
Yes. Montana officers can arrest based on probable cause from observations, statements, and field testing—even without a breath or blood test.

Conclusion

In Montana, a DUI arrest doesn’t require a failed breath test. Officers are empowered to act based on the totality of the situation, including driving behavior, physical signs of impairment, and field sobriety test results. While breath testing remains a valuable tool, it is not the only factor that determines whether an arrest occurs.

Understanding how DUI enforcement really works can help drivers make sense of what happens during a traffic stop. If you’ve ever wondered how DUI arrests unfold beyond the BAC number, Montana’s law provides a clear answer: impairment is what matters, not just the test result.

To learn more about the broader process, see our complete breakdown of how DUI laws work.

For more details on how these arrests are triggered, visit our article on what triggers a DUI arrest during a traffic stop.

February 3, 2026 | LDUIL

What Triggers a DUI Arrest in Montana?

Understanding what can lead to a DUI arrest in Montana is essential for all drivers. While most people are aware that driving with a high blood alcohol content (BAC) can result in legal consequences, the actual process leading to an arrest involves many steps—and often starts long before a breathalyzer test is administered. In Montana, DUI enforcement is a structured process built around observation, reasonable suspicion, and confirmation through chemical testing.

This post explains the specific actions, behaviors, and circumstances that typically lead law enforcement officers to initiate a DUI investigation. From the initial traffic stop to the decision to make an arrest, each phase follows predictable patterns under Montana law.

Whether you’re a new driver, a concerned parent, or someone trying to better understand the system, knowing what triggers a DUI arrest can help you stay informed. While this article is strictly educational and not legal advice, it provides clear, structured information that reflects how DUI arrests actually happen in Montana—starting with the moment a vehicle catches an officer’s attention.

Initial Behaviors That Lead to a Traffic Stop in Montana

The DUI process usually begins with a traffic stop, and the reason for that stop is often based on observable behavior. In Montana, officers can’t pull a driver over without some form of “reasonable suspicion,” which means they need to see something that suggests a traffic law may have been violated.

Common behaviors that raise suspicion include:

  • Swerving or drifting between lanes
  • Sudden or erratic braking
  • Driving too slowly or too fast for conditions
  • Failing to use turn signals
  • Running a stop sign or red light
  • Making wide or abrupt turns

These signs don’t confirm impairment, but they often prompt an officer to initiate a stop. Once contact is made, further observation begins. It’s not uncommon for a simple speeding ticket or broken taillight to evolve into a DUI investigation if the officer notices indicators of possible impairment after approaching the vehicle.

In Montana, even a minor infraction can legally justify a traffic stop, and that stop can quickly shift focus if alcohol is suspected.

Observable Signs of Impairment During the Stop

Once an officer makes contact with a driver, the next step is to assess the person’s behavior and appearance. Montana law allows officers to use their observations as part of the decision-making process when determining whether to escalate a stop into a DUI investigation.

Common signs that may raise concern include:

  • Slurred or mumbled speech
  • Bloodshot or watery eyes
  • The odor of alcohol or marijuana
  • Delayed or uncoordinated movements
  • Inconsistent or confused responses to questions

These indicators do not confirm intoxication on their own, but when combined, they can lead an officer to suspect impairment. This is often when a field sobriety test or breath test may be requested.

Importantly, these assessments are made in real time and are based on the officer’s training and experience. In Montana, officers receive specific instruction on how to identify impaired behavior and follow a standardized process to justify their actions.

Field Sobriety Tests and Their Role in the Arrest Decision

In Montana, once impairment is suspected, officers may administer a series of field sobriety tests (FSTs) to evaluate a driver’s coordination, focus, and motor skills. These tests are standardized across the U.S. and commonly include:

  • The Horizontal Gaze Nystagmus (HGN) test
  • The Walk-and-Turn test
  • The One-Leg Stand test

These tests are designed to detect subtle signs of intoxication that might not be obvious in casual interaction. Performance on these tests is subjective but guided by established criteria. For example, difficulty maintaining balance, starting before instructions are complete, or failing to follow directions precisely may be taken as signs of impairment.

Montana drivers are not legally required to perform field sobriety tests. However, refusal may still contribute to an officer’s overall assessment and does not prevent further testing or arrest. If the officer has enough reason to believe the driver is impaired, they may proceed to request a chemical test.

The Role of BAC Testing in Confirming Probable Cause

After field testing—or in some cases, before—officers may request a breath or blood test to measure a driver’s BAC. Montana follows an implied consent law, which means that by driving on public roads, all drivers are considered to have agreed to BAC testing if lawfully requested.

A BAC result of 0.08% or higher is generally sufficient to trigger a DUI charge for drivers 21 and older. For commercial drivers, the limit is 0.04%, and for drivers under 21, it’s just 0.02%.

Refusing to take a BAC test can lead to immediate license suspension and may still result in arrest if other signs of impairment are present. While refusal may limit some evidence, Montana law allows officers to proceed with charges based on observed behavior and performance on field tests.

BAC testing is often the final step before an arrest is made, providing objective data to support the decision.

Other Circumstances That Can Trigger a DUI Arrest

While most DUI arrests follow the pattern of traffic stop → observation → testing → arrest, there are cases where the process is different. In Montana, DUI arrests can also be triggered by:

  • Car accidents: If a driver is involved in a crash and impairment is suspected, officers may skip field tests and move directly to BAC testing.
  • Sobriety checkpoints: Though less common in Montana, legal checkpoints may lead to DUI arrests if impairment is detected.
  • Citizen reports: If someone reports an erratic driver and provides a vehicle description, law enforcement may locate and stop the vehicle to investigate.
  • Medical evaluations: If a driver is found unresponsive or confused, a medical professional may alert law enforcement to potential impairment.

Each of these scenarios provides a different path to the same outcome: a DUI arrest based on observed or tested evidence of impairment.

What Happens Immediately After a DUI Arrest in Montana

Once an officer determines that probable cause exists, the arrest is made. From this point, the driver is taken into custody and transported to a local detention center. The next steps typically include:

  • Booking: Basic personal information and fingerprints are collected.
  • Chemical Testing: A secondary BAC test may be performed at the station.
  • Vehicle Towing: The driver’s vehicle is often impounded.
  • License Action: Immediate administrative license suspension is possible, especially in cases of BAC test failure or refusal.

Montana distinguishes between administrative and criminal consequences, but both can begin as soon as the arrest occurs. The initial arrest process is procedural and moves quickly, often leaving little time for the driver to fully understand what’s happening in the moment.

Frequently Asked Questions About DUI Arrests in Montana

Can you be arrested for DUI without failing a breath test in Montana?
Yes. An officer can make an arrest based on behavior, field tests, and other observations, even without a BAC reading.

What if I refuse a breath or blood test during a DUI stop?
Montana’s implied consent law allows for immediate license suspension and other penalties if you refuse a chemical test.

Do officers need a reason to pull you over before a DUI arrest?
Yes. Officers must have a valid reason for the initial stop, such as a traffic violation or erratic driving behavior.

Are field sobriety tests required by law in Montana?
No. Drivers can decline these tests, but refusal may still factor into an officer’s decision to arrest.

Can I be arrested for DUI if I wasn’t driving at the time?
Possibly. If you are found in physical control of a vehicle and suspected of impairment (e.g., sitting in the driver’s seat with the engine running), you may still face arrest under Montana law.

Conclusion

In Montana, a DUI arrest is usually triggered by a combination of observed behavior, field sobriety test results, and BAC evidence. From the moment a vehicle is pulled over to the final decision to arrest, officers follow a structured process rooted in both visual cues and measurable data. Understanding this process helps make sense of how DUI enforcement works across the state.

For a broader explanation of this system, check out our overview of how DUI laws work.

You can also explore the specific situations that lead to arrests in our article on what triggers a DUI arrest during a traffic stop.

February 3, 2026 | LDUIL

Is Zero Tolerance BAC Enforced in Montana?

Driving under the influence is taken seriously in every state, but how the law treats underage drivers and blood alcohol content (BAC) limits can vary. In Montana, the concept of “zero tolerance” plays a critical role in enforcing DUI laws for younger drivers. This post explains how zero tolerance BAC laws work in Montana, what levels are considered illegal, and what drivers of different ages or vehicle types need to know. Whether you’re a resident, parent of a teen driver, or just trying to better understand Montana DUI law, this guide breaks down everything you need to know.

Montana law makes a clear distinction between adult DUI charges and underage drinking and driving. While the standard BAC limit for adults is 0.08%, the limit for drivers under 21 is much lower. This is part of what’s known as a “zero tolerance” policy, which applies additional scrutiny and consequences to young drivers with any detectable amount of alcohol in their system.

It’s also important to understand that zero tolerance doesn’t mean absolutely zero BAC in the literal sense. In most cases, the law allows for a very small threshold, such as 0.02%, to account for incidental exposure or errors in testing equipment. However, any result above that can trigger a DUI charge or administrative penalty for underage drivers in Montana.

This post walks through what Montana’s zero tolerance BAC law actually says, who it applies to, how enforcement works, and what the legal consequences may be. By the end, you’ll have a clearer picture of how BAC thresholds affect different age groups and driver categories in the state.

What Does “Zero Tolerance” Mean Under Montana DUI Law?

In Montana, “zero tolerance” is a legal approach applied to drivers under the age of 21. It refers to a lowered allowable BAC threshold—typically 0.02%—for these individuals. This differs from the standard 0.08% BAC limit applied to drivers 21 and older. The zero tolerance law is based on the idea that underage drinking is illegal in itself, so any presence of alcohol in a driver under 21 is considered a violation.

This law is strictly enforced to deter young drivers from consuming alcohol at all before getting behind the wheel. The 0.02% limit is designed to account for potential false positives or trace amounts of alcohol from medications or food products, but it effectively means that underage drivers must be alcohol-free when operating a vehicle.

Zero tolerance laws in Montana are part of a broader nationwide trend aimed at reducing youth-involved traffic incidents. While the state does not label these as “DUI” in every case, violations can still lead to license suspension, fines, and mandatory alcohol education programs. Importantly, these penalties are administrative in nature but can escalate if other charges are involved.

BAC Limits for Different Age Groups in Montana

Montana enforces different BAC thresholds based on the age of the driver:

  • Under 21: Any driver under the age of 21 with a BAC of 0.02% or higher can face penalties under the state’s zero tolerance laws.
  • 21 and Older: The legal BAC limit for adult drivers is 0.08%.
  • Commercial Drivers: Drivers operating a commercial vehicle are subject to a stricter BAC limit of 0.04%.

These distinctions reflect the varying levels of responsibility and legal accountability assigned to drivers in different categories. For underage drivers, even a small amount of alcohol detected during a traffic stop or roadside test can lead to serious consequences.

It’s also worth noting that Montana does not tolerate “margin of error” arguments when it comes to underage BAC limits. If the test shows 0.02% or higher, enforcement proceeds according to the law.

How BAC Testing Works in Zero Tolerance Enforcement

When a driver is pulled over and suspected of consuming alcohol, law enforcement may use field sobriety tests, breathalyzers, or blood tests to determine the person’s BAC. In the context of zero tolerance enforcement in Montana, officers are trained to evaluate all drivers the same way, but with a different threshold for underage individuals.

The most common method is the roadside breathalyzer, which gives an immediate BAC reading. If a driver under 21 tests at or above 0.02%, that information alone can be sufficient grounds for administrative penalties—even if the individual shows no signs of impairment.

Because Montana follows “implied consent” laws, refusing to take a BAC test can result in automatic penalties, such as license suspension. This applies to all drivers but is particularly important for underage drivers, who may mistakenly think they can avoid punishment by refusing a test.

Penalties for Violating Montana’s Zero Tolerance BAC Law

A violation of Montana’s zero tolerance law can result in a range of penalties, even if the offense is not charged as a full DUI. These can include:

  • Driver’s License Suspension: A first offense may lead to a 90-day suspension, while repeat offenses can result in longer suspensions.
  • Fines: Penalties often include administrative fines and fees, especially if reinstating a suspended license.
  • Alcohol Education: Offenders may be required to complete an alcohol awareness or education program.
  • Possible DUI Charges: If the BAC is high enough or other factors are involved (e.g., reckless driving), full DUI charges may be filed.

These penalties are designed to discourage underage drinking and driving before it becomes a more serious pattern of behavior. While not as severe as adult DUI charges in all cases, the consequences are still meaningful and long-lasting.

Exceptions and Clarifications in Montana Law

Montana’s law provides few exceptions when it comes to underage BAC enforcement. However, there are a few clarifications worth noting:

  • Medical Alcohol: Trace amounts of alcohol from certain medicines may not result in penalties if the level is below 0.02%.
  • Testing Errors: Rarely, issues with equipment calibration or officer procedure can be grounds for contesting the result—but this must be handled through proper administrative channels.
  • No Tolerance for Repeat Offenders: Any prior alcohol-related offense may increase the severity of penalties, even if the new BAC reading is low.

Overall, while the law is called “zero tolerance,” it is enforced with the understanding that some situations may warrant further investigation. Still, the goal is strict compliance and deterrence.

How Zero Tolerance Affects Driving Privileges

Losing a driver’s license—even temporarily—can have major consequences for younger drivers. In Montana, a suspension from a zero tolerance violation may affect:

  • School Attendance: If a teen relies on driving to attend school or activities.
  • Employment: Many part-time jobs for teens or young adults require reliable transportation.
  • Insurance Rates: A zero tolerance offense can increase auto insurance premiums for years.

While the zero tolerance policy is framed as a protective measure, it carries serious implications for how underage drivers manage their daily responsibilities. The law is designed not just to punish but to intervene before more dangerous habits take hold.

Frequently Asked Questions About Montana Zero Tolerance Laws

What is the BAC limit for drivers under 21 in Montana?
The legal limit is 0.02% for drivers under the age of 21. Any reading at or above this amount can result in penalties under the zero tolerance law.

Can an underage driver be charged with DUI for a BAC under 0.08%?
Yes. Even though the standard DUI limit is 0.08%, Montana’s zero tolerance law means that underage drivers can face penalties at just 0.02% BAC.

What happens if an underage driver refuses a breath test in Montana?
Refusal to submit to a BAC test can result in automatic license suspension under Montana’s implied consent laws, regardless of age.

Does Montana offer hardship licenses for underage drivers after suspension?
In some cases, the state may allow restricted driving privileges for school or work, but this is not guaranteed and must be approved through the proper channels.

Is the 0.02% limit strictly enforced?
Yes. Law enforcement treats 0.02% as the enforceable limit for underage drivers. Any reading at or above that level may trigger penalties.

Conclusion

Montana enforces a clear and strict zero tolerance policy for underage drinking and driving. With a BAC limit of 0.02% for drivers under 21, the state emphasizes deterrence, early intervention, and public safety. While the law may not treat these cases as full DUI offenses in every situation, the consequences are still impactful. From license suspension to mandatory education programs, zero tolerance laws are designed to shape safer behavior from the start.

For more on how these thresholds are applied, visit our detailed guide to blood alcohol content and legal limits.

You can also explore how age and vehicle type affect these rules in our article on legal alcohol limits by age, vehicle type, and driver status.

February 3, 2026 | LDUIL

Is the BAC Limit Different for Commercial Drivers in Montana?

Understanding Montana’s BAC Laws for Commercial Drivers

In Montana, the rules for impaired driving are not one-size-fits-all. The legal blood alcohol content (BAC) limit varies depending on who’s driving and what kind of vehicle they operate. One key distinction applies to commercial drivers, who are held to a significantly stricter standard than typical motorists.

While the standard legal BAC limit for most drivers in Montana is 0.08%, commercial driver’s license (CDL) holders are subject to a lower threshold of 0.04% when operating a commercial motor vehicle (CMV). This stricter limit is enforced under both federal regulations and Montana state law, reflecting the greater responsibility associated with driving large or hazardous vehicles.

This article explores how the BAC limit differs for commercial drivers in Montana, what types of vehicles and jobs fall under these rules, and the consequences of violating them. We’ll also look at how DUI charges can affect a commercial driver’s career and licensing status—even if the offense occurs in a personal vehicle.

What Is the Legal BAC Limit for Commercial Drivers in Montana?

Montana law, aligned with federal commercial motor vehicle (CMV) safety standards, sets the legal BAC limit for CDL holders at 0.04% when operating a commercial vehicle. This is half the standard limit applied to non-commercial drivers, which is 0.08%.

This reduced limit applies to drivers operating any vehicle that requires a commercial driver’s license, such as:

  • Semi-trucks
  • Delivery trucks over 26,001 pounds
  • Passenger vehicles transporting 16 or more people
  • Tanker trucks
  • School buses
  • Hazmat transport vehicles

The reasoning behind the stricter standard is clear: commercial vehicles are larger, heavier, and more dangerous in accidents. Even small amounts of alcohol can impair judgment, reaction time, and motor skills—putting public safety at greater risk.

Because of this, Montana aggressively enforces DUI laws among CDL holders, and drivers are expected to comply with both state regulations and Federal Motor Carrier Safety Administration (FMCSA) rules.

What Happens If a Commercial Driver Exceeds 0.04% BAC?

If a commercial driver in Montana is found to have a BAC of 0.04% or higher while operating a commercial vehicle, they may face both criminal charges and administrative penalties, including:

  • DUI criminal charges under Montana law
  • Immediate out-of-service order for 24 hours
  • Suspension of commercial driving privileges for at least 1 year
  • Disqualification of CDL for life on a second offense
  • Fines and potential jail time
  • SR-22 insurance filing requirement
  • Termination from employment

Unlike standard DUI penalties, which typically result in license suspension for personal driving, CDL disqualification affects a driver’s entire ability to work in a commercial driving role. Even if the conviction doesn’t involve a traffic accident, simply testing over 0.04% while in a commercial vehicle is enough to trigger these penalties.

Additionally, employers who require clean driving records may terminate CDL holders following any DUI charge, regardless of the final court outcome. This makes the consequences especially serious for those who rely on their license for income.

Can a CDL Holder Be Charged with DUI in a Personal Vehicle?

Yes. In Montana, commercial drivers can be charged with DUI even while operating their personal vehicle, and the consequences may still affect their commercial driving status.

While the legal BAC limit for non-commercial drivers remains 0.08%, a DUI conviction—regardless of the vehicle involved—can lead to:

  • Suspension of personal driving privileges
  • SR-22 filing
  • Mandatory alcohol education or treatment
  • One-year CDL disqualification for a first offense
  • Lifetime CDL revocation for a second offense

This means a CDL holder who drives their personal car after drinking and registers a 0.08% BAC may lose their commercial license, even though they weren’t on duty or driving a commercial vehicle at the time.

Montana, like many other states, follows FMCSA guidelines for DUI-related offenses and considers all DUI convictions—not just those involving a CMV—when determining disqualification periods.

Other Alcohol-Related Violations That Impact CDL Status

A DUI conviction isn’t the only alcohol-related offense that can jeopardize a commercial driver’s license in Montana. CDL holders may also face penalties for:

  • Refusing a BAC test (implied consent violation)
  • Operating a CMV with any detectable amount of alcohol (0.01%–0.039%)
  • Possessing alcohol in the cab or trailer area
  • Driving a CMV within 4 hours of alcohol consumption (per FMCSA regulations)

Even if a CDL holder tests between 0.01% and 0.039% BAC, they may still receive an immediate 24-hour out-of-service order, although it may not result in criminal charges.

Employers and law enforcement take these infractions seriously because they point to lapses in judgment that could put others at risk. For drivers in industries like hazmat transport, public transit, or school transportation, the tolerance for risk is even lower.

Employment Consequences of a DUI for Commercial Drivers

A DUI conviction or BAC violation can end a commercial driving career. In Montana, employers who hire CDL holders often have strict policies regarding alcohol-related offenses. Even if a driver is not formally convicted or is only found to be over the limit without showing impairment, the consequences can include:

  • Immediate job termination
  • Loss of future employment opportunities
  • Disqualification from company insurance
  • Blacklisting from industry networks or job boards

For owner-operators, the impact is financial. Insurance costs may spike, clients may cancel contracts, and the ability to maintain DOT registration may be jeopardized. Carriers and brokers often screen for DUIs when verifying safety records, and a recent violation may make it nearly impossible to secure loads.

Some drivers are able to return to work after completing alcohol education or treatment programs, but many employers require years of clean history before rehiring someone with a DUI on their record.

How to Protect a CDL in Montana

CDL holders must be more cautious than the average driver when it comes to alcohol use. The safest course of action is to avoid driving at all after consuming any alcohol, even if you feel sober.

To protect your CDL and stay compliant:

  • Never consume alcohol within 4 hours of going on duty
  • Avoid carrying alcohol in your vehicle
  • Know the lower 0.04% BAC limit when operating any CMV
  • Understand that personal vehicle DUIs count against your CDL
  • Comply immediately with any BAC testing request
  • Use a personal BAC tester if you’re unsure of your level

Montana’s penalties for DUI or alcohol-related offenses don’t just affect your license—they can impact your income, employment record, and long-term career. Being proactive and responsible is the only way to avoid life-changing consequences.

Frequently Asked Questions About Commercial Driver BAC in Montana

What is the legal BAC limit for commercial drivers in Montana?
The limit is 0.04% BAC when operating a commercial motor vehicle.

Does a DUI in a personal vehicle affect my CDL?
Yes. A DUI in any vehicle can result in CDL disqualification, even if you weren’t on duty.

What happens if I refuse a BAC test as a commercial driver?
Refusal leads to immediate license suspension and can result in CDL disqualification, even without a conviction.

Can I be fined or penalized for BAC under 0.04%?
Yes. Even BAC between 0.01% and 0.039% can lead to a 24-hour out-of-service order, per federal rules.

Will my employer be notified if I’m cited for DUI?
Most likely, yes. BAC violations and DUI charges are reported to the Montana MVD and commercial driver clearinghouses.

Conclusion

Montana’s DUI laws for commercial drivers are strict by design. With a legal BAC limit of just 0.04%—half the standard limit—CDL holders are held to a higher standard because of the potential risks involved in operating commercial vehicles. These rules apply whether you’re behind the wheel of a semi-truck or your own personal vehicle. A single DUI conviction can disqualify you from commercial driving for a year—or even for life on a second offense.

To learn more about alcohol limits across all driver categories in Montana, read our guide on blood alcohol content and legal limits.
For a breakdown of how BAC limits change by age, vehicle type, and license status, visit legal alcohol limits by age, vehicle type, and driver status.