Minn. Stat. § 169A.54
Subd. 1. Revocation periods for DWI convictions.
Except as provided in subdivision 7, the commissioner shall revoke the driver's license of a person convicted of violating section
(3) for an offense occurring within ten years of a qualified prior impaired driving incident:
169A.20 (driving while impaired) or an ordinance in conformity with it, as follows:
Subd. 2. Driving while impaired by person under age 21.
If the person convicted of violating section 169A.20 (driving while impaired) is under the age of 21 years at the time of the violation, the commissioner shall revoke the offender's driver's license or operating privileges for a period of six months or for the appropriate period of time under subdivision 1, clauses (1) to
(5), for the offense committed, whichever is the greatest period.
Subd. 3. Juvenile adjudications.
For purposes of this section, a juvenile adjudication under section 169A.20 (driving while impaired), an ordinance in conformity with it, or a statute or ordinance from another state in conformity with it is an offense.
Subd. 4. Violations involving personal injury.
Whenever department records show that the violation involved personal injury or death to any person, at least 90 additional days must be added to the base periods provided in subdivisions 1 to 3.
Subd. 5. Violations involving alcohol concentration of 0.20 or more.
If the person is convicted of violating section 169A.20 (driving while impaired) while having an alcohol concentration of 0.20 or more as measured at the time, or within two hours of the time, of the offense, the commissioner shall revoke the person's driver's license for twice the period of time otherwise provided for in this section.
Subd. 6. Applicability of implied consent revocation.
(b) Paragraph (a) does not apply to:
Subd. 7. Alcohol-related commercial vehicle driving violations.
(a) The administrative penalties described in subdivision 1 do not apply to violations of section 169A.20, subdivision 1 (driving while impaired crime), by a person operating a commercial motor vehicle unless the person's alcohol concentration as measured at the time, or within two hours of the time, of the operation was 0.08 or more or the person violates section 169A.20, subdivision 1, clauses
Subd. 8. Underage drinking and driving violations.
The administrative penalties described in section 169A.33, subdivision 3, apply to violations of section 169A.33 (underage drinking and driving).
Subd. 9. Alcohol-related school bus driving violations.
The administrative penalties described in section 171.3215 (canceling school bus endorsements for certain offenses) apply to violations of section 169A.20 (driving while impaired) by a person driving, operating, or in physical control of a school bus or Head Start bus.
Subd. 10. License revocation; court invalidation.
Subd. 11. Chemical use assessment.
When the evidentiary test shows an alcohol concentration of 0.07 or more, that result must be reported to the commissioner. The commissioner shall record that fact on the driver's record. When the driver's record shows a second or subsequent report of an alcohol concentration of 0.07 or more within two years of a recorded report, the commissioner may require that the driver have a chemical use assessment meeting the commissioner's requirements. The assessment must be at the driver's expense. In no event shall the commissioner deny the license of a person who refuses to take the assessment or to undertake treatment, if treatment is indicated by the assessment, for longer than 90 days. If an assessment is made pursuant to this section, the commissioner may waive the assessment required by section 169A.70.