BAC limits — Missouri Permit Test
BAC limits on the Missouri permit test — 7 rules, each with the reason behind it and a question on it while it is fresh.
The rules
It is illegal to drive with a blood alcohol content of 0.08% or more.
Point zero eight is the line for an adult driver. Below it you can still be charged; above it the number alone is the offense.
It is illegal to drive with a blood alcohol content (BAC) of 0.08% or more
The blood alcohol limit for a driver under 21 is 0.02%.
Under twenty-one the limit is barely above zero, because for that age the state's answer is simply not to drink and drive.
0.04% for commercial vehicle drivers and 0.02% if under 21
The blood alcohol limit for a commercial vehicle driver is 0.04%.
Half the ordinary limit, because the vehicle is many times the weight.
0.04% for commercial vehicle drivers and 0.02% if under 21).
If your BAC is .08% or more, or .02% or more for a minor, the officer takes your license and gives you a notice.
The license goes at the roadside. Everything after that is about getting it back.
the officer will take your license away and give you a notice
The notice tells you that your license will be suspended or revoked after 15 days.
Fifteen days is the window to request a hearing, and it starts the moment the notice is handed over.
This notice tells you that your license will be suspended or revoked (and you will not be able to legally drive) after 15 days.
The notice also lets you request a hearing or, if eligible, an immediate 90-day Restricted Driving Privilege.
Two ways to keep driving, and both of them start with the piece of paper you were handed.
The notice also allows you to request a hearing or, if eligible, request an immediate 90-day Restricted Driving Privilege (RDP).
If you are given a hearing you may continue to drive legally until 15 days after the decision is mailed to you.
The hearing pauses the clock rather than stopping it. The fifteen days start again at the decision.
If you are given a hearing, you may continue to legally drive until 15 days after a decision is mailed to you.
On the test
What is the blood alcohol content limit for an adult Missouri driver?
0.08%. Point zero eight is the line for an adult driver. Below it you can still be charged; above it the number alone is the offense. Missouri Driver Guide, p.71: “It is illegal to drive with a blood alcohol content (BAC) of 0.08% or more”
How this works
Most practice tests hand you a bank of questions and leave the manual somewhere else. This one puts them together.
You read one law and the reason behind it, then answer a question on that law while it is still fresh. Get it right and you move on; get it wrong and you have found the gap while it is cheap to fix, not on the morning of the exam.
Learning one rule at a time, and proving it immediately, is what turns a manual you skimmed into something you actually know — and it makes studying feel like getting somewhere rather than like waiting to find out.
What it costs
- One payment, once — not a subscription. Nothing renews and there is nothing to cancel, for an exam you sit one time.
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- Paying opens the rest of the cards, unlimited full-length practice tests, and retests built from exactly the questions you got wrong.
- Every level up to Prepared — 3 tests passed in a row.
- Do the work, fail the real exam, and we refund you.
Where these come from
Every rule here is checked against Missouri Driver Guide, published by the Missouri Department of Revenue, and against the state code itself. Last checked 2026-09-16.
- src/assets/drivers-manuals/MO.pdf (Missouri Driver Guide, Revised August 2026, retrieved 2026-09-14)
- src/assets/drivers-manuals/MO.pages.txt (plain pdftotext over that PDF; sha256 pinned in SOURCES.json)
- src/assets/drivers-manuals/SOURCES.json (sha256, folio offset 2, folioMarker, nonLawPages and the extraction flag, each with its measured basis)