DUI Laws in Missouri

0.08 for drivers generally; 0.04 for commercial motor vehicle drivers; 0.02 for drivers under 21 (administrative suspension).

A first driving-while-intoxicated offense is a class B misdemeanor, punishable by up to six months in jail and a fine of up to $1,000. It adds 8 points. The administrative suspension for a test at or above the limit with no prior alcohol-related contacts in five years is 30 days followed by a 60-day restricted driving privilege (which requires an ignition interlock); if the driver files proof of a certified ignition interlock, there is no suspension period and a 90-day restricted period applies instead. Having a child under 17 in the vehicle raises the offense to a class A misdemeanor.

DWI becomes a felony based on the driver's prior record or the harm caused. It is a class E felony for a 'persistent offender' (two or more prior intoxication-related traffic offenses, or one involving injury or death); a class D felony for an 'aggravated offender' (three or more priors) or when the DWI causes physical injury through criminal negligence; a class C felony for a 'chronic offender' (four or more priors) or when it causes serious physical injury; and a class B felony for a 'habitual offender' (five or more priors) or when it causes a death. Causing a death can be a class A felony in some cases, including for someone already found guilty of a class B DWI. The offender categories use prior offenses committed on separate occasions, with no time limit except for the 'prior offender' (misdemeanor) level, which uses a 5-year window.

Refusing a chemical test after a lawful request results in a one-year license revocation (or a one-year denial for unlicensed residents and revocation of a nonresident's privilege).

5 years. A 'prior offender' is someone found guilty of one intoxication-related traffic offense that occurred within five years of the current offense; prior offenders face a class A misdemeanor. Administrative suspension length also depends on alcohol-related contacts in the preceding five years.

After at least 10 years, a person with a single misdemeanor (or municipal ordinance) intoxication-related traffic offense, not involving a commercial vehicle, and no later intoxication-related offense or alcohol-related enforcement contact, can ask the court to expunge all records of the arrest, plea, trial or conviction. Only one such expungement is allowed in a lifetime. How long a DWI stays on the Missouri driving record was not found on an official page.

A court or the Director of Revenue may grant a limited driving privilege to a person whose license is suspended or revoked when the person must drive for work, medical treatment, school, or similar needs, subject to eligibility limits. A circuit court must grant a limited driving privilege to an otherwise eligible person who has filed proof of installation of a certified ignition interlock device.