A Complete Guide to Idaho DUI Laws: From First Offense to Felony Charges

June 20, 2025

A Complete Guide to Idaho DUI Laws: From First Offense to Felony Charges

Introduction

Idaho, known for its scenic beauty and outdoor recreation, also has stringent Driving Under the Influence (DUI) laws aimed at ensuring road safety. Operating a vehicle while impaired by alcohol or drugs carries significant consequences in the Gem State, with penalties escalating sharply for repeat offenses and those involving high Blood Alcohol Content (BAC) levels or injuries. Understanding these regulations is critical for anyone driving in Idaho.

The General Framework of Idaho DUI Laws

In Idaho, a person can be charged with DUI if they are found to be driving or in actual physical control of a motor vehicle while:

Under the influence of alcohol, drugs, or any other intoxicating substances, or a combination thereof, to a degree that renders them incapable of safely driving; OR
Having a Blood Alcohol Concentration (BAC) of $0.08%$ or more.

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Per Se DUI Law: Idaho operates under a "per se" law for alcohol impairment. This means if your BAC is at or above a certain legal limit, you are legally considered to be under the influence, regardless of whether your driving appears impaired.

For drivers 21 and older: The legal BAC limit is $0.08%$ .
For commercial vehicle operators: The legal BAC limit is $0.04%$ .
For drivers under 21 (Zero Tolerance Law): Idaho has a strict "zero tolerance" policy for underage drivers. If a driver under 21 has a BAC of $0.02%$ or higher, they can be charged with DUI.

Even if your BAC is below the specific "per se" limits, you can still face DUI charges if law enforcement can prove that your driving ability was impaired based on observations, field sobriety tests, or other evidence.

Implied Consent Law

Idaho has a robust implied consent law (Idaho Code § 18-8002). By driving or being in actual physical control of a motor vehicle in the state, you are legally deemed to have given your consent to evidentiary chemical testing (blood, breath, or urine) to determine your BAC or the presence of drugs/intoxicating substances if a law enforcement officer has probable cause to believe you are driving under the influence and you are lawfully arrested for DUI.

Refusal to Test: Refusing to submit to a chemical test after a lawful arrest for DUI in Idaho carries immediate and severe administrative penalties, separate from any criminal prosecution. Your refusal can also be used as evidence against you in court.

First refusal: Automatic 1-year driver's license suspension. There are generally no restricted driving privileges available during this suspension. Additionally, a civil penalty of $250 is imposed, and mandatory installation of an Ignition Interlock System (IID) for one year following the end of the suspension period is required.
Second refusal (within 10 years): Automatic 2-year driver's license suspension, with no restricted driving privileges.
Third or subsequent refusal (within 10 years): Automatic 3-year driver's license suspension.

You have 7 days to request a hearing to contest the administrative license suspension for refusal.

Idaho DUI Statistics

Impaired driving remains a significant public safety challenge in Idaho. While specific comprehensive statewide 2024 statistics are still being compiled, the Idaho Transportation Department (ITD) regularly reports on crash data. According to data from previous years, impaired driving is a leading contributing factor to serious injuries and fatalities on Idaho's roads. The ongoing enforcement efforts highlight the state's commitment to reducing these incidents.

Penalties for DUI in Idaho

Idaho's DUI penalties are substantial and become significantly more severe with each subsequent conviction. Idaho uses a 10-year "look-back" period to determine if a DUI is a repeat offense for sentencing enhancement purposes. However, a DUI conviction remains on your criminal record permanently.

First Offense DUI (Misdemeanor)

For a first-time DUI conviction in Idaho (no prior convictions within the last 10 years):

Jail Time: Up to 6 months imprisonment. In practice, many first-time offenders may receive a suspended sentence with probation, often substituting jail time with Sheriff's Labor Detail or community service (8 hours of community service usually equals 1 day of jail).
Fines: Up to $1,000, plus court costs (often around $202.50).
License Suspension: 90 to 180 days (3 to 6 months) driver's license suspension by the court. The DMV also imposes an administrative suspension (e.g., 90 days for failing a test, 1 year for refusal).
- Restricted License: May be eligible for a restricted license for work, school, or treatment after 30 days of absolute suspension if an IID is installed.
Ignition Interlock Device (IID): Mandatory installation of a state-approved IID for a period of 1 year after license reinstatement.
Substance Abuse Evaluation and Treatment: Mandatory evaluation and completion of any recommended alcohol/drug education or treatment programs.
Probation: Usually 1 to 2 years of unsupervised probation, unless aggravating circumstances exist.

Enhanced Penalties for High BAC (Excessive DUI - BAC of $0.20%$ or higher)

If your BAC is $0.20%$ or higher, even for a first offense, penalties are enhanced:

Jail Time: Mandatory minimum 10 days up to 1 year.
Fines: Up to $2,000.
License Suspension: Minimum 1-year license suspension, often with no eligibility for a restricted license during this period.

Repeat Offenses (Within 10-year look-back)

Second Offense DUI (Misdemeanor): (Second conviction within 10 years of a prior conviction)
- Jail Time: Mandatory minimum 10 days up to 1 year imprisonment. (If BAC $0.20%$ or higher, 30 days up to 5 years).
- Fines: Up to $2,000. (If BAC $0.20%$ or higher, up to $5,000).
- License Suspension: Mandatory 1-year license suspension. If BAC $0.20%$ or higher, 1 to 5 years. No eligibility for a restricted license during this period.
- Ignition Interlock Device (IID): Mandatory for at least 1 year after license reinstatement.
- Substance Abuse Treatment: Mandatory evaluation and treatment.
- Probation: Often longer, and may be supervised.
Third Offense DUI (Felony): (Third conviction within 10 years of two prior convictions)
- Prison Time: Mandatory minimum 30 days up to 5 years in state prison.
- Fines: Up to $5,000.
- License Suspension: Mandatory 1 to 5-year license suspension. May apply for a restricted license after 1 year with an IID.
- Ignition Interlock Device (IID): Mandatory for at least 1 year after license reinstatement (as condition of restricted license, then full reinstatement).
- Substance Abuse Treatment: Mandatory evaluation and treatment.
- Probation: Supervised probation, often with strict conditions.
- Felony Criminal Record: A permanent felony conviction with severe lifelong implications.

Aggravated DUI (Felony):

If a DUI causes bodily harm to another person, it is charged as a felony:

Prison Time: Up to 15 years in prison.
Fines: Up to $5,000.
License Suspension: 1 to 5 years.
Restitution: Mandatory restitution to the victim.
Subsequent Felony DUI within 15 years: Any subsequent DUI conviction within 15 years of a felony DUI will also be charged as a felony.

Vehicular Manslaughter (Felony):

If a DUI results in the death of another person, it can be charged as vehicular manslaughter:

Prison Time: Up to 15 years in prison.
Fines: Up to $15,000.
License Revocation: Permanent license revocation.

Conclusion

Idaho's DUI laws are comprehensive and severe, reflecting the state's unwavering commitment to preventing impaired driving. From mandatory jail time (or alternatives) and fines for a first offense to lengthy prison sentences, extensive license revocations, and felony convictions for repeat or aggravated offenses, the consequences are designed to deter and punish. Understanding the state's "per se" and "zero tolerance" BAC limits, the strict implied consent law (and the severe penalties for refusal), and the impact of aggravating factors is paramount for every driver in Idaho. For anyone facing a DUI charge in the Gem State, immediate consultation with an experienced Idaho DUI defense attorney is strongly advised to navigate the complexities of the legal system and safeguard your rights and future.

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