## Second-offense DUI penalties in Montana A second DUI conviction is in a different category from a first. Mandatory minimum jail goes up sharply, license suspension extends, ignition interlock becomes mandatory for longer periods, and the social and professional consequences multiply. ### Montana 2nd-offense framework - **Jail exposure:** 7 days mandatory, up to 1 year - **License consequence:** 1 year suspension - **Lookback period:** 10 years (the window during which a prior counts as a "prior") ## Why the lookback matters Lookback / washout periods determine whether your prior counts. Three patterns: - **Short lookback (5-7 years)** — older priors don't enhance the new offense (FL, MS, NV, MI, NC, AZ, IN, ND, RI, WA, MS, MD) - **Standard lookback (10 years)** — most states - **Long lookback (15-20+ years)** — AK, IL, NE, DC - **Lifetime lookback** — CO, MA, MO, NM, TX, VT, WI: ANY prior anywhere on your record counts forever Out-of-state priors generally count if they would have qualified as a DUI in the new state. ## What gets harder at offense #2 **Mandatory minimum jail** — most states impose a multi-day or multi-week mandatory minimum that judges cannot suspend in full **Longer license suspension** — typically 1-3 years (vs 90 days to 1 year on a 1st) **Mandatory ignition interlock** — for the entire suspension period in many states; up to 2-3 years post-reinstatement **Higher fines** — typically $500-$2,500 minimum (often $5,000+ when surcharges added) **Mandatory alcohol/substance evaluation and treatment** — often residential or intensive outpatient **Vehicle restrictions** — some states require vehicle forfeiture or special plates **Higher probation costs and terms** — 2-5 years post-incarceration **Felony elevation** — many states elevate a 2nd or 3rd offense to a felony (NY, OK, others within their lookback) ## Aggravators that compound 2nd-offense penalties - **High BAC** (0.15 or 0.20+) — often doubles mandatory minimums - **Child in vehicle** — separate child-endangerment charge in many states - **Accident with injury** — felony in nearly every state - **Refusal of breath test** — separate license consequences - **Driving on suspended license** — additional charge - **Open container / drug possession** — adds to the charge stack ## Diversion is rare Most states limit DUI diversion to true first offenders. Pre-trial intervention, deferred adjudication, and ARD-style programs that work for first offenses generally don't apply to seconds. ## What you should do Don't plead at first appearance. A 2nd-offense DUI case has technical defenses (calibration of the breath device, traffic-stop legality, blood-draw chain of custody, validity of the prior conviction, lookback computation) that a qualified Montana DUI defense attorney can identify. Prior conviction CHALLENGES — collateral attacks on the validity of the prior — are often the most productive defense angle. Most Montana criminal defense attorneys offer free initial consultations and accept payment plans. --- *This guide is general information about Montana law as of early 2026 and is not legal advice. DUI sentencing rules are complex and reform-prone. Talk to a licensed Montana criminal-defense attorney about your specific case.*