A Montana DUI can take your license for 90 days, 6 months, 1 year, 3 years, or life, and more than one of those can apply to the same arrest. The length depends on what triggered the action: a conviction, a refused test, your age, or a commercial license. This page puts every period in one place, with the statute for each. It is part of our Montana DUI Guide, and it goes deeper than the summary on our license suspension and hearings page.
Every DUI-Related Period in One Table
| Trigger | License action | MCA |
|---|---|---|
| First DUI conviction | 6-month suspension | § 61-5-208(2)(b)(i) |
| Second DUI conviction (prior within 10 years) | 1-year suspension, continuing until required treatment is completed | § 61-5-208(2)(b)(ii) |
| Third or later DUI conviction | 1-year suspension, continuing until required treatment is completed | § 61-5-208(2)(b)(iii) |
| Felony DUI (fourth or later) | 1-year revocation, as a felony in which a motor vehicle is used | § 61-5-205(1)(b), (3) |
| Test refusal, first | 6-month suspension, no probationary license | § 61-8-1032(4)(a)(i) |
| Test refusal, second or later within 5 years of a previous refusal | 1-year suspension, no probationary license | § 61-8-1032(4)(a)(ii) |
| Under-21 offense, first conviction | 90-day suspension | § 61-8-1007(3)(a)(iv)(B) |
| Under-21 offense, second conviction | 6-month suspension | § 61-8-1007(3)(a)(iv)(B) |
| Under-21 offense, third or later conviction | 1-year suspension | § 61-8-1007(3)(a)(iv)(B) |
| CDL, first major offense | Commercial license suspended 1 year, or 3 years if hauling placardable hazardous materials | § 61-8-802(1)(a) |
| CDL, second major offense from a separate incident | Commercial license suspended for life, with reinstatement possible after at least 10 years | § 61-8-802(1)(b) |
These periods match the table the Motor Vehicle Division publishes on its suspensions and revocations page. The sections below explain the parts of the table that people most often misread.
Conviction Suspensions by Offense Number
When a court reports a DUI conviction, the department suspends the license for the period in MCA § 61-5-208. A first offense is 6 months. A second offense, counted within the 10-year window of MCA § 61-8-1011, is 1 year. A third or later offense is also 1 year. Our guide to how long a DUI stays on your record explains how priors are counted.
The 1-year figure is a minimum in practice. If the year passes and the person has not completed the chemical dependency treatment required under MCA § 61-8-1009, the suspension remains in effect until treatment is completed. The one exception is where the assessment was done and the licensed addiction counselor found that treatment was not necessary (MCA § 61-5-208(5)).
A felony DUI is handled differently. The department must revoke, for 1 year, the license of a person convicted of any felony in the commission of which a motor vehicle is used (MCA § 61-5-205(1)(b), (3)). The Motor Vehicle Division's own revocation table lists fourth-offense DUI under that rule. A license issued after a felony DUI is also marked with the person's probation driving restrictions (MCA § 61-5-208(6)). See our felony DUI page.
Refusal Suspensions
Refusing a breath, blood, or oral fluid test triggers a separate suspension that does not depend on the criminal case. A first refusal is 6 months. A second or later refusal within 5 years of a previous refusal, as shown by the department's records, is 1 year (MCA § 61-8-1032(4)(a)). Refusing more than one test in the same incident counts once (MCA § 61-8-1032(2)(e)).
Two features make a refusal suspension harder to live with than a conviction suspension of the same length. The department may not issue a probationary license during it, and it carries a $300 administrative fee on top of the reinstatement fee (MCA § 61-8-1032(2)(f), (3)(a)). The only way to shorten it is to challenge the refusal suspension in district court within 30 days.
Drivers Under 21
A driver under 21 convicted of the 0.02 or any-active-THC offense in MCA § 61-8-1002(1)(e) faces a shorter scale: 90 days on a first conviction, 6 months on a second, and 1 year on a third or later (MCA § 61-8-1007(3)(a)(iv)(B)). A restricted or probationary license may not be issued until the reinstatement fee is paid and, if the driver was under 18 at the time of the offense, until at least 30 days of the suspension have been completed. A driver under 21 who is convicted of an ordinary DUI, such as the 0.08 offense, is on the adult scale instead. Our under-21 DUI page covers the charge.
Commercial Driver's Licenses
A commercial license has its own clock. A DUI conviction in any vehicle, a refusal, or a 0.04 result in a commercial motor vehicle is a major offense. The first one suspends the commercial license for 1 year, or 3 years if it happened while hauling placardable hazardous materials. A second from a separate incident means life, with reinstatement possible after a minimum of 10 years (MCA § 61-8-802). These run in addition to the ordinary suspension of the person's regular driving privilege. Our guide to CDL disqualification periods has the detail.
When Each Period Starts
- Conviction: from the date of conviction or forfeiture of bail (MCA § 61-5-208(3)(a)).
- Refusal: from the date of the violation, meaning the refusal (MCA § 61-8-1032(2)(d)).
- Driving while suspended: the added period starts on the last day of the earlier suspension or revocation (MCA § 61-5-208(3)(b)).
Periods That Stack on Top
| Event | License action | MCA |
|---|---|---|
| Convicted of driving while suspended or revoked | The department extends the suspension or revocation by 1 more year | § 61-5-212(2)(a) |
| Declared a habitual traffic offender (30 points in 3 years) | 3-year revocation from the date of the declaration | § 61-11-211 |
| Negligent homicide with a motor vehicle, or negligent vehicular assault | 1-year revocation | § 61-5-205(1)(a), (f) |
| Failure to appear in court or to comply with a sentence | Suspension until the court tells the department the problem is cured | § 61-5-214 |
The first two rows are covered in our guides to driving while suspended and habitual traffic offender points. In every case the department may act only as the statutes permit (MCA § 61-5-208(1)), so the first step is to identify which section the notice in your hand relies on.
This page explains Montana law in general as of the 2025 Montana Code Annotated. It is not legal advice about your specific case.