In Western Montana, losing a license often means losing the way to work. So one of the first questions after a DUI arrest is whether there is any lawful way to keep driving. The answer depends on which of two suspensions you are facing. This page explains both, and where an ignition interlock fits. It is part of our Montana DUI Guide, and it builds on our license suspension and hearings page.
Two Suspensions, Two Different Rules
A conviction suspension is imposed by the Motor Vehicle Division after a court reports a DUI conviction. It starts on the date of conviction (MCA § 61-5-208(3)(a)). A probationary license is possible.
A refusal suspension is imposed because a driver refused the breath, blood, or oral fluid test. It starts on the date of the refusal, and the statute says the department may not issue a probationary license during it (MCA § 61-8-1032(2)(f)). The way to fight a refusal suspension is a petition to the district court within 30 days, which our test refusal page explains.
When a Probationary License Is Available
| Reason for suspension | Length | Probationary license |
|---|---|---|
| First DUI conviction | 6 months | No minimum wait in the statute. The court must recommend it, and may require 24/7 testing or an interlock. |
| Second DUI (prior within 10 years) | 1 year | At least 45 days served, plus a court recommendation subject to § 61-8-1010. |
| Third or later DUI | 1 year | At least 90 days served, plus a court recommendation subject to § 61-8-1010. |
| Test refusal, first | 6 months | None. No probationary license during a refusal suspension. |
| Test refusal, second within 5 years | 1 year | None. No probationary license during a refusal suspension. |
Sources: MCA §§ 61-5-208(2)(b), 61-8-1010, and 61-8-1032(4)(a). One more rule catches people by surprise. On a second or later conviction, if the year passes and the required chemical dependency treatment is not finished, the suspension stays in effect until it is (§ 61-5-208(2)(b)). Our page on DUI classes and treatment covers that requirement.
What an Ignition Interlock Is
An ignition interlock is a breath-testing device wired into a vehicle. The driver gives a breath sample, and the vehicle will not start if the device detects alcohol above its set point. Montana law requires approved devices to take a deep lung breath sample, to resist tampering and show evidence of it, and to be difficult to circumvent (MCA § 61-8-1025).
When a Montana Court Orders One
- First offense: optional. If the court recommends a probationary license, it may require 24/7 testing or an interlock (MCA § 61-8-1010(1)).
- Second or later offense: the court must choose one of three things: order the 24/7 program or another court-approved testing program; restrict the person to an interlock-equipped vehicle during the probationary period if it recommends a probationary license; or order each vehicle the person owned at the time of the offense seized for forfeiture (MCA § 61-8-1010(2)).
- Felony DUI: an interlock is a condition of probation if the person is permitted to drive (MCA § 61-8-1008).
Notice what the statute does not say. It does not set an interlock term of six months or a year. Articles that quote a fixed Montana interlock period are describing other states.
Living With the Restriction
The restriction follows the driver, not one car. A person subject to it may not operate any vehicle that is not equipped with a device (MCA § 61-8-1024(1)). It is also a crime for someone else to knowingly help the restricted person start and operate the vehicle, or for anyone to knowingly circumvent the device. Each carries a fine of up to $500, up to 6 months in jail, or both. The one exception is starting the vehicle for safety or mechanical repair when the restricted person does not drive it.
Driving while under a court or department interlock order has a second consequence. If you are arrested for a new DUI, the interlock order by itself makes the new charge an aggravated DUI (MCA § 61-8-1001(1)(b)).
Other Routes to a Probationary License
- The 24/7 program. A person convicted of aggravated DUI or a second or later DUI who has been ordered into the program can, with proof of insurance, be made eligible for a restricted probationary license without first completing the waiting portion of the suspension (MCA § 44-4-1205(1)(b)). Falling out of compliance can bring the rest of the suspension back.
- DUI court. A DUI court may, in its discretion, authorize a probationary license for a person convicted of a second or later offense (MCA § 61-5-231). Missoula County Justice Court runs a DUI court called ROAD Court.
Getting Your License Back
When the suspension ends, the license is not automatically restored. It stays suspended until you pay the department a $200 reinstatement fee (MCA § 61-2-107(1)). A refusal also carries a separate $300 administrative fee (MCA § 61-8-1032(3)(a)). And driving before reinstatement is its own offense: driving while suspended for a DUI or a refusal carries 2 days to 6 months in jail or a fine of up to $2,000, or both, and adds a year to the suspension (MCA § 61-5-212).
This page explains Montana law in general as of the 2025 Montana Code Annotated. The Motor Vehicle Division sets its own application steps for a probationary license. It is not legal advice about your specific case.