484.3943(1) and (2)
The court may or must require a defendant to install an ignition interlock as a condition for restricted driving privileges as follows: First offense – 3 to 6 months (discretionary); second offense – (no requirement); and, third and subsequent offense – 12 to 36 months (mandatory).
The court may require a defendant to install an ignition interlock as a condition for the reinstatement of driving privileges. The period of use is determined by the court.
