What Is an "Excessive DUI" in Idaho? Understanding the Law and Its Penalties

In Idaho, a standard DUI is serious enough. But if your blood alcohol concentration (BAC) is significantly above the legal limit, the consequences increase dramatically. This is called an “Excessive DUI,” and it's one of the most severe forms of misdemeanor DUI offenses under Idaho law.

Whether you're facing charges or just trying to understand how Idaho treats high-BAC DUI cases, this post will walk you through what defines an Excessive DUI, how it's punished, and how it differs from a standard DUI.

What Is an Excessive DUI?

Under Idaho Code § 18-8004C, an “Excessive DUI” is defined as driving or being in actual physical control of a vehicle with a BAC of 0.20% or higher. For context, the legal limit for a standard DUI in Idaho is 0.08%. If your BAC is 2.5 times that limit, the state assumes your level of impairment is dangerous enough to warrant harsher penalties—even for a first offense.

It's important to note: you can be charged with an Excessive DUI even if this is your first encounter with law enforcement and even if your driving didn't seem egregiously reckless. The high BAC alone is enough.

How Is BAC Measured?

BAC is typically determined by a breathalyzer test, blood draw, or occasionally a urine test. In Idaho, refusing to take one of these tests after arrest triggers an automatic license suspension under the state's Implied Consent Law.

Once the test results confirm a BAC of 0.20% or greater, the charge can be upgraded to Excessive DUI. Officers may file this enhanced charge immediately or later once lab results are confirmed—especially in the case of blood tests.

First Offense Excessive DUI: Penalties and Process

Unlike a standard first DUI, an Excessive DUI is a misdemeanor, but with significantly enhanced penalties. These include:

• Mandatory jail sentence: Minimum of 10 days up to 1 year in county jail. You must serve at least 2 consecutive days.

  • Pro tip: If you are arrested prior to midnight and bond out the next morning, this counts as your first "consecutive" 48 hours for the purpose of sentencing.

• Fines: Up to $2,000

• License suspension: At least 1 year mandatory suspension with no restricted privileges (you cannot drive at all).

• Ignition interlock device: Required for at least 1 year after license reinstatement.

• Substance abuse evaluation: Mandatory, must be paid for out-of-pocket, and completed prior to sentencing in most cases.

• Probation: Supervised probation is often ordered, and can include random drug/alcohol testing, counseling, and regular check-ins.

The biggest distinctions between a standard DUI and an Excessive DUI are the mandatory jail time and the absolute license suspension without any allowances for work or hardship.

Second Excessive DUI (Within 5 Years): Felony Charges

If you're charged with a second Excessive DUI within five years of a prior Excessive DUI, the charge will be elevated to a felony. That changes the landscape entirely:

• Prison time: Minimum of 30 days jail time, up to 5 years in state prison.

• Fines: Up to $5,000

• License suspension: Minimum of 1 year, maximum of 5.

• Felony record: A felony DUI will remain on your record for life, severely affecting employment, housing, and civil rights like firearm ownership.

Felony charges are prosecuted more aggressively and carry long-term consequences. The court will also likely view your case through the lens of protecting public safety, not just rehabilitating a single incident.

How Is “Actual Physical Control” Defined?

Idaho doesn't require you to be actively driving to be charged with DUI—or Excessive DUI. Simply being in actual physical control of a vehicle while intoxicated can be enough. That means sitting in the driver's seat with the keys in the ignition, even if the car isn't moving. Courts have held that if you had the ability to operate the vehicle, you're considered in control.

So, sleeping it off in your parked car while intoxicated is not a safe legal option if you still have access to operate the vehicle.

Common Legal Questions

Can I fight an Excessive DUI charge in Boise?
Yes. Legal defenses may include challenging the accuracy of the BAC test, the validity of the traffic stop, or whether proper procedures were followed during arrest and testing. The margin of error on BAC devices, medical conditions, and even diet can sometimes affect results.

Will I have a criminal record?
Yes, unless you are able to fight the charges. An Excessive DUI conviction—whether misdemeanor or felony—results in a criminal record, which may affect employment, education, and housing.

Is there any way to drive during suspension?
Not for the initial suspension. Idaho law does not allow restricted driving privileges for Excessive DUI convictions during the mandatory license suspension period.

Final Thoughts

An Excessive DUI in Idaho is more than just a tougher version of a standard DUI. It comes with mandatory jail time, harsher fines, stricter license restrictions, and the possibility of a felony record for repeat offenses. Unlike other states that might offer leniency for first-time high BAC cases, Idaho takes a hard line approach.

The message is clear: driving with a BAC of 0.20% or higher—even once—can alter the course of your life in major ways. If you're facing this charge, understanding the law is the first step in navigating a difficult path forward. Give us a call or schedule a consult to see how we can help.