Drinking and Driving while under 21 years old sometimes referred to as a "baby dui"

Underage driving with a BAC of at least 0.02 but not more than 0.05.
Minors who are caught driving under the influence in Colorado are sometimes prosecuted under a separate statute. The decision of what the minor is charged with depends a lot on the blood or breath alcohol content of the driver. If the bac is over a 0.05 the minor will be prosecuted under the normal DUI statute and face the same consequences as an adult driver who is caught driving under the influence. Some minors who are caught driving under the influence have less than 0.05 but still face charges because they should not be consuming alcohol underage. If the driver is under 21 years old but has a bac of at least 0.02 but not more than 0.05 then they will face what is sometimes called a baby DUI. The consequences of a baby DUI are different but still carry potential criminal and administrative penalties.

(a.5) (I) It is a class A traffic infraction for any person under twenty-one years of age to drive a motor vehicle or vehicle when the person's BAC, as shown by analysis of the person's breath, is at least 0.02 but not more than 0.05 at the time of driving or within two hours after driving. The court, upon sentencing a defendant pursuant to this subparagraph (I), may, in addition to any penalty imposed under a class A traffic infraction, order that the defendant perform up to twenty-four hours of useful public service, subject to the conditions and restrictions of section 18-1.3-507, C.R.S., and may further order that the defendant submit to and complete an alcohol evaluation or assessment, an alcohol education program, or an alcohol treatment program at such defendant's own expense.

(II) A second or subsequent violation of this paragraph (a.5) shall be a class 2 traffic misdemeanor.