For a commercial driver's license holder, a DUI conviction or a test refusal brings a disqualification of 1 year for a first major offense, 3 years if it happened while hauling placardable hazardous materials in a commercial motor vehicle, and life for a second major offense from a separate incident. Those periods come from MCA § 61-8-802 and match the federal table at 49 CFR 383.51. This page sets them side by side. It is part of our Montana DUI Guide and goes deeper than our CDL DUI page.
The Periods at a Glance
| Offense | First, in a commercial vehicle | First, in a personal vehicle | First, hauling hazmat | Second, separate incident |
|---|---|---|---|---|
| DUI conviction (alcohol or a controlled substance) | 1 year | 1 year | 3 years | Life |
| Alcohol concentration of 0.04 or more in a commercial motor vehicle | 1 year | Does not apply | 3 years | Life |
| Refusing a test under an implied consent law | 1 year | 1 year | 3 years | Life |
Sources: 49 CFR 383.51, Table 1, rows 1 to 4, and MCA § 61-8-802(1). Montana's statute says its commercial driver rules are meant to conform to the federal regulations (MCA § 61-8-801(2)(d)), and on these periods the two agree.
What Counts as a Major Offense
Montana uses the term "major offense." For alcohol and drugs, it covers (MCA § 61-8-802(2)):
- a refusal to take a test under an implied consent law in Montana or any other jurisdiction;
- a test result under another jurisdiction's implied consent law showing 0.08 or more in a noncommercial vehicle or 0.04 or more in a commercial one;
- a conviction, in Montana or elsewhere, for driving or being in actual physical control of a motor vehicle while under the influence of alcohol, a drug, or both; and
- a conviction for 0.08 or more in a noncommercial vehicle or 0.04 or more in a commercial motor vehicle.
The list also includes non-alcohol offenses, such as leaving the scene of an injury accident, using a vehicle to commit a felony, and driving a commercial vehicle while disqualified. Any of them counts as the "first" when a later DUI is the second.
One Year for a First Offense, Three With Hazmat
On receiving a report of a first major offense by a person who holds, or is required to hold, a commercial license, the department must suspend the commercial license and disqualify the person from operating a commercial motor vehicle for 1 year (MCA § 61-8-802(1)(a)). The person does not have to have been working, or in a truck. The federal rule states that a CDL holder is subject to disqualification "if the holder drives a CMV or non-CMV" and is convicted of a listed violation (49 CFR 383.51(a)(3)). Our guide for a CDL holder in a personal vehicle covers that situation.
A separate administrative track applies in a commercial vehicle. A driver whose alcohol concentration is 0.04 or more while driving or in actual physical control of a commercial motor vehicle is suspended for 1 year on the officer's certified report, with no conviction needed and no provision for a restricted probationary commercial license (MCA § 61-8-805(1)). Any measured amount or detected presence of alcohol also means being placed out of service for 24 hours (MCA § 61-8-805(2)).
The 3-year period depends on the load, not on the driver's endorsements. The Montana statute applies it when the major offense "occurred while operating a commercial motor vehicle transporting placardable hazardous materials" (MCA § 61-8-802(1)(a)). The federal table uses the same idea: a first conviction or refusal while operating a commercial vehicle transporting hazardous materials. A driver with a hazmat endorsement who is arrested in a personal pickup is in the 1-year column under both texts.
Life for a Second Offense
A second or subsequent major offense "arising from an incident that is separate from the prior major offense" brings suspension for life (MCA § 61-8-802(1)(b)). Three details matter:
- No time limit. Unlike the 10-year window used for sentencing a second DUI, the CDL statute contains no lookback period. A major offense from many years ago still counts as the first.
- Mixed offenses count. Under the federal rule, the second can be "any combination of offenses" in the table, committed in a commercial or a non-commercial vehicle (49 CFR 383.51(a)(4)). A refusal years ago plus a DUI conviction now is two.
- One incident counts once. A refusal and a DUI conviction from the same arrest are not separate incidents. For refusals, a prior conviction of a major offense from a separate incident has the same effect as a previous refusal (MCA § 61-8-1032(4)(b)).
Reinstatement After 10 Years
Montana's lifetime suspension is "subject to department rules adopted to implement federal rules allowing for license reinstatement, if the person is otherwise eligible, upon completion of a minimum suspension period of 10 years." The federal rule sets the conditions: a state may reinstate after 10 years if the person has voluntarily entered and successfully completed an appropriate rehabilitation program approved by the state. A person reinstated this way who is later convicted of another disqualifying offense must not be reinstated again (49 CFR 383.51(a)(6)).
Reinstatement is not available at all for one category. A commercial license is suspended for life, with no reinstatement at any time, for using a vehicle in a felony involving the manufacture, distribution, or dispensing of a controlled substance (MCA § 61-8-804).
How the CDL Period Fits With Your Regular License
The disqualification is in addition to the action against the regular driving privilege. After a refusal, the statute says so directly: the CDL suspension applies "in addition to any action taken against the driver's noncommercial driving privileges" (MCA § 61-8-1032(4)(b)). After a DUI conviction, the ordinary 6-month or 1-year suspension applies as well. See our suspension lengths table.
So a commercial driver convicted of a first DUI may be able to get a probationary license for a personal vehicle, as described in our guide on getting a probationary license, while still being barred from any commercial driving for the full year. The rule that lets a suspended driver earn a restricted license through a court-ordered program expressly does not apply to a commercial license suspended under the CDL statutes (MCA § 61-5-208(7)(b)).
Why the Conviction Cannot Be Kept Off the Record
For a CDL holder, a court may not take any action, including deferring imposition of judgment, that would prevent a conviction for a traffic violation in any type of motor vehicle from appearing on the driving record (MCA § 61-11-101(4)(a)). Combined with the rule that no DUI sentence can be deferred (MCA § 61-8-1011(4)), that leaves contesting the charge, or the suspension itself, as the ways to protect the license. A suspension for a 0.04 result or a refusal in a commercial vehicle can be challenged by petition within 30 days in the district court of the county where the finding or refusal was made (MCA § 61-8-808).
This page explains Montana and federal law in general as of the 2025 Montana Code Annotated and the Code of Federal Regulations in effect on October 9, 2026. It is not legal advice about your specific case.