South Dakota Underage DUI

Zero Tolerance Means Zero

South Dakota enforces a zero tolerance policy for drivers under 21. Under SDCL 32-23-21, any driver under 21 operating a vehicle with a blood alcohol concentration of 0.02% or more can face a separate criminal offense and license consequences — far below the 0.08% threshold that applies to adult drivers.

The 0.02% threshold is deliberately set at a level that essentially prohibits any alcohol consumption before driving. A single beer can push a lightweight 18-year-old above 0.02%. The law isn't about impairment — it's about the fact that the driver is underage and should not have consumed alcohol at all.

How Underage DUI Differs from Standard DUI

The legal path splits depending on the minor's BAC level:

BAC between 0.02% and 0.079%: This is a separate under-21 offense under SDCL 32-23-21, rather than the standard criminal DUI charge. Upon conviction, the court suspends the license for 30 days for a first offense and 180 days for a second; it may issue a restricted order for employment, school, or counseling.

BAC at 0.08% or above: The minor may face the same standard criminal DUI charge as an adult — a Class 1 misdemeanor under SDCL 32-23-2, carrying up to one year in jail and a $2,000 fine. The separate under-21 offense and its court-ordered suspension may apply in addition to the standard DUI penalties.

This dual-layer system means an underage driver who blows 0.10% may face both the standard criminal DUI process (court, fines, potential jail, license revocation) and the separate under-21 offense and suspension.

Minor in Possession Charges

A DUI stop involving an underage driver frequently generates a separate Minor in Possession (MIP) charge under SDCL 35-9-2. This is a Class 2 misdemeanor, carrying up to $500 in fines and 30 days in jail for a first offense.

The MIP charge is independent of the DUI charge. A minor can face an MIP for possessing or consuming alcohol — whether or not they were above the DUI threshold and whether or not they were actually driving. An open container in the vehicle does not by itself establish every element of the MIP charge; the facts must show that the minor possessed or consumed alcohol.

For a § 35-9-2 offense involving a person under 21 and alcohol in a vehicle, SDCL 32-12-52.4 provides 30 days for a first conviction, 180 days for a second, and one year for a third or subsequent. These court-ordered suspensions run separately from any DUI-related revocation.

Impact on the Minor's Future

The long-term consequences for underage drivers are more severe than most families realize at the time of arrest:

College applications and scholarships: Many universities ask about criminal convictions, and some scholarship programs disqualify applicants with alcohol-related offenses. An SIS (Suspended Imposition of Sentence) can mitigate this by sealing the record after probation — but using the one-time SIS option on an underage DUI means it's unavailable for any future misdemeanor charge during the minor's adult life.

Military enlistment: Alcohol-related convictions can complicate or disqualify military service applications, depending on the branch and the number of offenses.

Auto insurance: A DUI conviction on a young driver's record triggers massive insurance premium increases — often doubling or tripling rates for years. The SR-22 filing requirement adds an additional $21 to $26 per month for three years.

Professional licensing: Certain professional licenses (nursing, teaching, law enforcement) require disclosure of all criminal convictions, including sealed SIS records in some application processes.

What Parents Should Know

If your child has been arrested for an underage DUI in South Dakota, the most critical immediate step is determining which track applies — the separate criminal under-21 offense (0.02% to 0.079%) or the full criminal DUI path (0.08% and above). The defense strategy, available outcomes, and urgency level differ substantially between them.

For cases at or above 0.08%, the process mirrors the adult DUI system. The South Dakota First-Offense DUI Guide covers the complete dual-track framework — criminal court and administrative licensing — that applies regardless of the defendant's age.

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