Iowa Code § 321J.2A: Persons under the age of twenty-one.

1. A person who is under the age of twenty-one shall not operate a motor vehicle while having an alcohol concentration, as defined under section 321J.1, of .02 or more. The driver’s license or nonresident operating privilege of a person who is under the age of twenty-one and who operates a motor vehicle while having an alcohol concentration of .02 or more shall be revoked by the department for the period of time specified under section 321J.12. A revocation under this section shall not preclude a prosecution or conviction under any applicable criminal provisions of this chapter. However, if the person is convicted of a criminal offense under section 321J.2, the revocation imposed under this section shall be superseded by any revocation imposed as a result of the conviction.

2. In any proceeding regarding a revocation under this section, evidence of the results of analysis of a specimen of the defendant’s blood, breath, or urine is admissible upon proof of a proper foundation. The alcohol concentration established by the results of an analysis of a specimen of the defendant’s blood, breath, or urine withdrawn within two hours after the defendant was driving or in physical control of a motor vehicle is presumed to be the alcohol concentration at the time of driving or being in physical control of the motor vehicle.