Missouri · DWI · Checked October 2026
Ignition Interlock Rules in Missouri
Ignition Interlock Rules in Missouri: What Are the Rules?
When Missouri requires an ignition interlock after a DWI.
- First offense
- For reinstatement after a first conviction if BAC was 0.15 or more or there was property damage or personal injury; also a condition of the restricted driving privilege after a first administrative suspension
- Repeat offenses
- For reinstatement when the record shows more than one alcohol- or drug-related enforcement contact
First Offense in Missouri
for reinstatement after a first conviction if BAC was 0.15 or more or there was property damage or personal injury; also a condition of the restricted driving privilege after a first administrative suspension
Repeat Offenses in Missouri
for reinstatement when the record shows more than one alcohol- or drug-related enforcement contact
How the Program Works in Missouri
maintained on every vehicle you operate for at least 6 months after reinstatement; violations in the last 3 months extend it until 3 consecutive violation-free months; a court may order interlock after a single contact
More on DWI Law in Missouri
See the full overview of DWI laws in Missouri and read about how ignition interlock programs work.
This page summarizes Missouri law from official sources, checked October 2026. It isn't legal advice; a lawyer licensed in Missouri can advise on your case.
Frequently Asked Questions
Is an Ignition Interlock Required for a First DWI in Missouri?
for reinstatement after a first conviction if BAC was 0.15 or more or there was property damage or personal injury; also a condition of the restricted driving privilege after a first administrative suspension
Is an Interlock Required for Repeat Offenses?
for reinstatement when the record shows more than one alcohol- or drug-related enforcement contact