Key points
It is illegal to drive with a BAC of 0.08% or more, 0.04% for commercial drivers and 0.02% if under 21.
Source: Handbook p. 71
“It is illegal to drive with a blood alcohol content (BAC) of 0.08% or more (0.04% for commercial vehicle drivers and 0.02% if under 21).”
Missouri Driver Guide, Handbook p. 71Even one drink can affect your driving, and two drinks could put you over the legal limit.
Source: Handbook p. 71
“Even one drink is likely to affect your ability to drive safely and in many cases, two drinks could place you over the legal blood alcohol limit.”
Missouri Driver Guide, Handbook p. 71If your BAC is 0.08% or more (0.02% for minors), the officer takes your license and gives you a notice.
Source: Handbook p. 67
“If your BAC level is .08% or more (or for minors .02% or more), the officer will take your license away and give you a notice.”
Missouri Driver Guide, Handbook p. 67The notice lets you request a hearing or, if eligible, an immediate 90 day Restricted Driving Privilege.
Source: Handbook p. 67
“The notice also allows you to request a hearing or, if eligible, request an immediate 90-day Restricted Driving Privilege (RDP).”
Missouri Driver Guide, Handbook p. 67A second administrative offense within 5 years brings a 1 year license revocation.
Source: Handbook p. 68
“*2nd Offense within a 5-year period - One-year license revocation”
Missouri Driver Guide, Handbook p. 68A first DWI or BAC conviction can mean up to 6 months in jail and a fine up to $500.
Source: Handbook p. 68
“1st Offense - Spend up to six months in jail. Pay up to a $500 fine.”
Missouri Driver Guide, Handbook p. 68A third DWI or BAC offense brings a 10 year license denial.
Source: Handbook p. 68
“*3rd Offense - Ten-year license denial.”
Missouri Driver Guide, Handbook p. 68Refusing a chemical test means your license is taken away for 1 year.
Source: Handbook p. 70
“you refuse to take a chemical test to determine your BAC, your driver license will be taken away for one year.”
Missouri Driver Guide, Handbook p. 70Injuring or killing someone while drinking or using drugs can mean 2 to 7 years in jail, a $5,000 fine and 5 years without a license.
Source: Handbook p. 67
“Spend two to seven years in jail; • Pay a $5,000 fine; and/or • Lose your driver license for five years.”
Missouri Driver Guide, Handbook p. 67DWI penalties in Missouri are the same whether the impairment comes from drugs or alcohol.
Source: Handbook p. 71
“The penalties for DWI in Missouri are exactly the same regardless of whether the impairment is from drugs or alcohol.”
Missouri Driver Guide, Handbook p. 71
Numbers to know
| Number | What it means | Manual |
|---|---|---|
| 0.08% | BAC limit for adult drivers | Handbook p. 71 |
| 0.04% | BAC limit for commercial vehicle drivers | Handbook p. 71 |
| 0.02% under 21 | BAC limit for drivers under 21 | Handbook p. 71 |
| 15 days | time after the notice before the administrative suspension or revocation starts | Handbook p. 67 |
| 90 days | immediate Restricted Driving Privilege you may request | Handbook p. 67 |
| 1 year within 5 years | revocation for a second administrative offense within a 5 year period | Handbook p. 68 |
| 6 months and $500 | maximum jail and fine for a first DWI or BAC conviction | Handbook p. 68 |
| 10 years | license denial for a third DWI or BAC offense | Handbook p. 68 |
| 1 year | license loss for refusing a chemical test | Handbook p. 70 |
| 2 to 7 years, $5,000, 5 years | jail, fine and license loss for injuring or killing someone while impaired | Handbook p. 67 |
| 0.15% | BAC conviction level that requires an ignition interlock for reinstatement | Handbook p. 70 |
3 questions from the Missouri practice test
1. For a driver age 21 or older operating a noncommercial vehicle in Missouri, what is the lowest BAC covered by the general alcohol per se threshold?
- 0.02% or more
- 0.04% or more
- 0.08% or more
- 0.12% or more
Show answer
0.08% or more. Missouri identifies 0.08% BAC or more as illegal for an ordinary adult driver. The lower 0.04% threshold applies to commercial vehicle drivers, while 0.02% applies when the driver is under 21. The number is a legal limit, not a promise that lower alcohol levels are safe or acceptable for every person. Treat any drinking before driving as a reason to arrange another ride, rather than trying to estimate a personal margin.
2. What administrative action may follow a Missouri BAC result of 0.08% or more?
- No action until a criminal conviction
- Only a verbal warning at the roadside
- The officer takes the license and gives a notice
- Automatic permanent revocation with no notice
Show answer
The officer takes the license and gives a notice. At or above 0.08% BAC, the guide says the officer takes the license and gives the driver a notice. The notice explains that a suspension or revocation will begin after 15 days and may include a 15-day driving permit when the officer indicates it. This administrative process is separate from waiting for a court conviction. Do not confuse the notice period with permission to ignore later license restrictions.
3. After an administrative BAC suspension notice in Missouri, when does the suspension or revocation generally begin?
- After 15 days
- At the instant of the traffic stop
- After 30 days
- Only after a criminal trial
Show answer
After 15 days. The administrative notice tells the driver that the license will be suspended or revoked after 15 days. That notice may include a 15 day driving permit when the officer indicates it, and the driver may request a hearing or, if eligible, an immediate restricted privilege. The instant stop choice ignores the stated waiting period, while the criminal trial choice confuses an administrative action with a court case. Mark the number 15 as the transition from notice to the administrative license action.
Practice this topic
Lock it in with alcohol and dui questions from the free Missouri practice test. Every answer comes with a plain English explanation.
Source: the Missouri Driver Guide, Chapter 10: Alcohol, Drugs, and Driving. This lesson is a plain English summary, not the law itself; where it differs, the manual and the statute govern. Last checked 2026-09-27.