Idaho's rule on DUI penalties turns on a feature the national template does not capture: BAC limits: 0.08% for adults; 0.04% for commercial drivers; zero-tolerance for drivers under 21; enhanced penalties at 0.20%+. A first offense: First-offense DUI is typically a misdemeanor with fines, possible jail, license suspension, alcohol evaluation, and ignition-interlock conditions. Felony threshold: A third DUI within 10 years is a felony; DUI with excessive BAC or causing injury can escalate charges. The controlling authority is Idaho Code § 18-8004. Lookback: Prior DUI convictions within 10 years enhance penalties; a third DUI within 10 years is a felony.. Ignition interlock: Ignition interlock is commonly required for restricted privileges after DUI.
Key takeaways
- BAC limits: 0.08% for adults; 0.04% for commercial drivers; zero-tolerance for drivers under 21; enhanced penalties at 0.20%+
- Lookback period: Prior DUI convictions within 10 years enhance penalties; a third DUI within 10 years is a felony.
- First-offense range: First-offense DUI is typically a misdemeanor with fines, possible jail, license suspension, alcohol evaluation, and ignition-interlock conditions.
- Felony threshold: A third DUI within 10 years is a felony; DUI with excessive BAC or causing injury can escalate charges.
- Ignition interlock: Ignition interlock is commonly required for restricted privileges after DUI.
- Primary authority: Idaho Code § 18-8004.
Worked example under Idaho law
The illustration below uses only rules already stated for Idaho. It is a research hypothetical, not a prediction of what a court will do.
A driver in Idaho is charged with a first impaired-driving offense and wants to know what the statute actually sets.
- Start with the alcohol limits: 0.08% for adults; 0.04% for commercial drivers; zero-tolerance for drivers under 21; enhanced penalties at 0.20%+
- Read the first-offense range: First-offense DUI is typically a misdemeanor with fines, possible jail, license suspension, alcohol evaluation, and ignition-interlock conditions.
- Ask when the charge becomes a felony: A third DUI within 10 years is a felony; DUI with excessive BAC or causing injury can escalate charges. Lookback: Prior DUI convictions within 10 years enhance penalties; a third DUI within 10 years is a felony.
- Interlock: Ignition interlock is commonly required for restricted privileges after DUI.
Idaho DUI under § 18-8004 proceeds in magistrate or district court with parallel ITD administrative license actions. Defense reviews the stop and breath/blood foundations.
Blood alcohol limits in Idaho
0.08% for adults; 0.04% for commercial drivers; zero-tolerance for drivers under 21; enhanced penalties at 0.20%+
Lookback window for prior offenses
Prior DUI convictions within 10 years enhance penalties; a third DUI within 10 years is a felony.
First-offense penalties
First-offense DUI is typically a misdemeanor with fines, possible jail, license suspension, alcohol evaluation, and ignition-interlock conditions.
When a Idaho DUI becomes a felony
A third DUI within 10 years is a felony; DUI with excessive BAC or causing injury can escalate charges.
Ignition interlock and license consequences
Ignition interlock is commonly required for restricted privileges after DUI.
How a typical Idaho DUI case unfolds
Idaho DUI under § 18-8004 proceeds in magistrate or district court with parallel ITD administrative license actions. Defense reviews the stop and breath/blood foundations.
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Case law: DUI penalties in Idaho
STATE of Idaho, Plaintiff-Respondent, v. Richard ROBINETT, Defendant-Appellant
STATE of Idaho, Plaintiff-Respondent, v. Richard ROBINETT, Defendant-Appellant, 141 Idaho 110 (2005)
…erdict convicting Richard Robinett (Robinett) of aggravated driving under the influence (DUI) and vehicular manslaughter. I. FACTUAL AND PROCEDURAL BACKGROUND On May 11, 2001, Robinett, his daughter Patricia Robinett (Patricia), and his brother-in-law Russell Lawrence (Lawrence), were drinking at a bar in Lewiston. At 2:25 a.m., they left in Robinett's car with Robinett driving…
Practitioners open STATE of Idaho, Plaintiff-Respondent, v. Richard ROBINETT, Defendant-Appellant when Idaho DUI penalties turns on the distinction in this sentence: "Richard Robinett (Robinett) of aggravated driving under the influence (DUI) and vehicular manslaughter. I." Do not lift it out of the facts the court was deciding.
STATE of Idaho, Plaintiff-Appellant, v. Dennis John HALSETH, Defendant-Respondent
…ults of a warrantless blood draw from a driver suspected of driving under the influence of alcohol on the ground that an implied consent statute is not an exception to the warrant requirement announced in Missouri v. McNeely, 569 U.S. -, 133 S.Ct. 1552, 185 L.Ed.2d 696 (2013). We affirm the granting of the motion to suppress. *644 I. Factual Background. On November 5, 2012, a P…
STATE of Idaho, Plaintiff-Appellant, v. Dennis John HALSETH, Defendant-Respondent is worth reading on Idaho DUI penalties because the court put the point in its own words: "Missouri v. McNeely, 569 U.S. -, 133 S.Ct. 1552, 185 L.Ed.2d 696 (2013). We affirm the granting of the motion to suppress. *644 I. Factual Background." Use that passage as the starting point, then read the facts that precede it.
STATE of Idaho, Plaintiff-Respondent, v. Mary Lou KNOLL, Defendant-Appellant
STATE of Idaho, Plaintiff-Respondent, v. Mary Lou KNOLL, Defendant-Appellant, 110 Idaho 678 (1986)
…trict court decision upholding a judgment of conviction for driving under the influence of alcohol. The appeal presents two questions: (1) Does Idaho’s DUI statute create separate offenses — driving under the influence of alcohol, and driving with a proscribed blood-alcohol content — which require mutually exclusive methods of proof? (2) Is the result of a blood-alcohol test ad…
On DUI penalties, STATE of Idaho, Plaintiff-Respondent, v. Mary Lou KNOLL, Defendant-Appellant speaks to the Idaho dispute in this passage: "The appeal presents two questions: (1) Does Idaho’s DUI statute create separate offenses — driving under the influence of alcohol, and driving with a proscribed blood-alcohol content — which require mutually exclusive methods of proof?" The surrounding opinion shows how the court applied that language to the record.
STATE of Idaho, Plaintiff-Respondent, v. Christian F. SCHMOLL, Defendant-Appellant
…Schmoll appeals from his judgment of conviction for felony driving under the influence of alcohol, entered upon his conditional guilty plea preserving the right to appeal the denial of his motion in limine. We affirm. I. BACKGROUND In February 1999, Schmoll was arrested for driving under the influence of alcohol (DUI) in Montana, and thereafter was convicted of a felony DUI in…
Practitioners open STATE of Idaho, Plaintiff-Respondent, v. Christian F. SCHMOLL, Defendant-Appellant when Idaho DUI penalties turns on the distinction in this sentence: "Schmoll appeals from his judgment of conviction for felony driving under the influence of alcohol, entered upon his conditional guilty plea preserving the right to appeal the denial of his motion in limine. We affirm. I." Do not lift it out of the facts the court was deciding.
STATE of Idaho, Plaintiff-Respondent, v. Richard CHENEY, Jr., Defendant-Appellant
…was towed from the intersection. Cheney pled not guilty to driving under the influence of alcohol, and a trial on this matter was set for April 21, 1987. On April 20, 1987, the prosecutor moved to amend the complaint against Cheney to reflect the state’s intention of relying on the theory that Cheney was guilty of the offense of exercising actual physical control over his moto…
On DUI penalties, STATE of Idaho, Plaintiff-Respondent, v. Richard CHENEY, Jr., Defendant-Appellant speaks to the Idaho dispute in this passage: "Cheney pled not guilty to driving under the influence of alcohol, and a trial on this matter was set for April 21, 1987." The surrounding opinion shows how the court applied that language to the record.
STATE of Idaho, Plaintiff-Respondent, v. Ernest P. BARKER, Defendants Appellant
…S, Chief Judge. Ernest Barker was arrested and charged with driving under the influence (DUI)t I.C. § 18-8004. At trial, he moved for an order requiring the state to elect to prosecute by using only one of the two methods of proof described in § 18-8004, thereby precluding prosecution by the other method. The magistrate denied the motion, and instructed the jury that the state…
Idaho opinions such as STATE of Idaho, Plaintiff-Respondent, v. Ernest P. BARKER, Defendants Appellant are cited where DUI penalties is disputed. The court stated: "S, Chief Judge. Ernest Barker was arrested and charged with driving under the influence (DUI)t I.C. § 18-8004." That is the language to brief; the rest of the decision supplies the procedural posture.
In the Matter of the Driver’s License Suspension of Kyle J. Reisenauer. Kyle J. REISENAUER, Petitio — Jones, J
…e Department’s reading of Section 18-2002A(4)(a) — that the driving under the influence element (“person had been driving or was in actual physical control of a motor vehicle while under the influence of alcohol, drugs or other intoxicating substances”), is not particularly an indicator of impairment, or a separate ground for license suspension, but primarily an indicator that…
Idaho opinions such as In the Matter of the Driver’s License Suspension of Kyle J. Reisenauer. Kyle J. REISENAUER, Petitio — Jones, J are cited where DUI penalties is disputed. The court stated: "e Department’s reading of Section 18-2002A(4)(a) — that the driving under the influence element (“person had been driving or was in actual physical control of a motor vehicle while under the influence of alcohol, drugs or other intoxicating substances”), is not particularly an in" That is the language to brief; the rest of the decision supplies the procedural posture.
Frequently asked questions
What is the legal BAC limit in Idaho?
0.08% for adults; 0.04% for commercial drivers; zero-tolerance for drivers under 21; enhanced penalties at 0.20%+
Is a first DUI a felony in Idaho?
A third DUI within 10 years is a felony; DUI with excessive BAC or causing injury can escalate charges.
Will I need an ignition interlock device?
Ignition interlock is commonly required for restricted privileges after DUI.
This guide covers Idaho impaired-driving law as of 2026. Sentencing grids, administrative DMV rules, and local diversion programs change — verify the live statute and speak with counsel about your charging document.