DUI in Montana: the law, the limits and the device
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Montana calls it DUI — driving under the influence, and you will see drunk driving used for the same offense. What follows is what this state sets, taken from its own published rules rather than from a national summary.
What Montana law actually requires
Montana gives the court a choice rather than a mandate on a first offense: it can send you to the 24/7 sobriety and drug monitoring program, or issue a probationary license restricted to an interlock-equipped vehicle. Either way you pay for the monitoring yourself.
- First offense: For the probationary period set by the court. The underlying suspension is 6 months for a first DUI conviction or a first refusal, and a year for a second or subsequent within 10 years
- Lockout threshold: Set by the approved device
- Program run by: The sentencing court, with records held by the Montana Motor Vehicle Division
Source: mvdmt.gov, checked 2026-08-23
DUI vs DUI in Montana
In Montana there is one offense and one label. If you have seen DWI, OWI or OVI used elsewhere, that is another state’s vocabulary for the same conduct — nothing about the seriousness changes when you cross a state line, only the letters on the paperwork.
Whatever it is called, the licensing consequence is the same shape: a suspension, then the device as the condition of driving again. All six abbreviations, side by side →
Can you get a DUI on a bike or a horse in Montana?
It turns on one word in the statute. Where the law says “vehicle”, no engine is required and the charge can reach a bicycle, a horse or a mobility scooter. Where it says “motor vehicle”, the analysis is different. This is decided by your state’s own wording, not by national custom, and it is the first thing to check before assuming a bike ride home is safe.
Where this state departs from the national picture
Most of what people read about drunk driving is written for the country as a whole. These are the points where Montana does something of its own.
Not conducted in Montana
Montana is one of ten states where checkpoints are prohibited by state law, the state constitution or how the courts there read the federal one. Enforcement uses saturation patrols instead, so the absence of checkpoints is not an absence of enforcement.
NHTSA, Countermeasures That Work: Publicized Sobriety Checkpoints
How often this happens in Montana
Federal crash records show the scale the state is legislating against, and how it compares with the country.
Cases are heard where the stop happened, and volume shapes local practice. These MT counties record the most:
Source: NHTSA Fatality Analysis Reporting System, 2020–2022. Counts crashes where police recorded that a driver had been drinking, which is narrower than the federal 0.08 measure and therefore understates the real figure. Montana runs above the national share.
What it costs to get driving again in Montana
Montana does not publish a price cap we could verify, so the quote is the number and your only leverage is a competitor nearby. The national reference points are installation and a monthly fee, with calibration visits every 30 to 60 days.
The two clocks in Montana
The court case and the licensing case run separately. The licensing side moves first, and in the strictest states the window to request a hearing is measured in days — it runs whether or not you have hired anyone.
DUI questions in Montana
Is it called DUI or DUI in Montana?
Montana uses DUI — driving under the influence. You will also see drunk driving used for the same thing. The label follows the state, not the seriousness of what happened, so paperwork from elsewhere may say something different about identical conduct.
What is the legal limit in Montana?
0.08% for drivers 21 and over, as in every state except Utah, which sits at 0.05%. Below the limit you can still be charged if an officer documents impairment. The reading that triggers the interlock here is a separate number: Set by the approved device
How long does the interlock stay on after a first offense in Montana?
For the probationary period set by the court. The underlying suspension is 6 months for a first DUI conviction or a first refusal, and a year for a second or subsequent within 10 years The program is run by The sentencing court, with records held by the Montana Motor Vehicle Division.
Can you get a DUI on a horse or a bicycle in Montana?
The answer is in whether the statute says “vehicle” or “motor vehicle”. Where it says vehicle, no engine is needed and the charge can reach a bike or a horse; where it says motor vehicle, it cannot. This is one of the most searched questions in the whole subject and one of the most confidently answered wrongly — the wording of your own state decides it.
Are DUI checkpoints legal in Montana?
No. Montana is one of ten states that do not run sobriety checkpoints — the ban rests on state law or the state constitution rather than the federal one. Enforcement there relies on saturation patrols instead.
A first DUI here →When a DUI is a felony in Montana →
When a charge becomes a felony → The test and the refusal → SR-22 and FR-44 →
Attorney advertising. InterlockDeviceNearMe is not a law firm, does not practice law, and does not give legal advice. Nothing here creates an attorney-client relationship. Requesting a consultation connects you with an independent attorney or a legal referral service, who decide separately whether to take your case. Case outcomes depend on facts we do not know, and no result is ever promised. Deadlines in DUI cases are short and vary by state — speak to a licensed attorney in your state before relying on anything you read here.