What Is an Excessive DUI in Idaho?

An excessive DUI in Idaho is not just "a bad DUI." It is a specific charge under Idaho Code § 18-8004C for driving with a blood alcohol concentration of 0.20 or higher. The penalties are heavier than a standard first DUI, and a second excessive offense within five years can become a felony.

If you were arrested and told your BAC was at or above 0.20, you need a clear picture of what that means in Idaho courts.

What Idaho law means by excessive DUI

Idaho Code § 18-8004C covers people who violate Idaho's DUI law while having an alcohol concentration of 0.20 or more. In plain English: the state treats a very high BAC as more serious than a standard DUI, even on a first offense.

That charge can sit on top of the basic DUI case. Prosecutors still have to prove the impaired driving case. The excessive label turns on the alcohol concentration evidence.

Penalties for a first excessive DUI

A first excessive DUI is generally charged as a misdemeanor, but the mandatory pieces matter:

• Mandatory minimum of 10 days in jail, with the first 48 hours served consecutively
• Fine of up to $2,000
• One-year driver's license suspension with no privileges during that suspension

Those are not soft guidelines. Courts have limited room on the mandatory minimums in the statute. Probation, alcohol treatment, and other conditions often get added on top.

Second excessive DUI within five years

A second excessive DUI within five years is a felony under § 18-8004C. That changes the exposure from county jail risk to potential prison time, and it changes how employers, licensing boards, and firearm rights can be affected later.

This path is different from a third DUI within ten years under § 18-8005(6). Idaho has more than one way a DUI case can become a felony. Excessive BAC is one of them.

Why the BAC evidence matters so much

Because so much of an excessive case turns on the number, the testing process deserves a hard look:

• Was the stop lawful?
• Were field sobriety tests administered correctly?
• Was the breath or blood test handled under proper procedure?
• Is the reported BAC accurate and admissible?

A high reading does not end the case by itself. It does raise the stakes if the reading holds up.

What to do if you are charged

Do not treat an excessive DUI like a routine traffic ticket. Get counsel early, keep track of any Idaho Transportation Department license deadlines, and avoid talking through the facts with anyone but your lawyer.

Browning Law defends DUI cases in Idaho Falls and across Eastern Idaho, including high-BAC and felony DUI matters. Allen Browning has tried 114+ cases to juries, including a unanimous acquittal on a felony DUI charge in 2021. Criminal defense cases use clear upfront fee arrangements. We do not offer payment plans. Free initial consultation.

If you want a straight read on your charge, start with our DUI lawyer in Idaho Falls page or call (208) 542-2700.

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This article provides general information about Idaho law as of 2026. It is not legal advice for any specific situation. Idaho Code sections referenced are cited where applicable. Consult an attorney about your individual circumstances.