Drunk and drugged driving laws in Utah
Utah has the strictest drunk driving limit in the country. In December 2018 it became the first state to set the legal limit at 0.05 blood alcohol concentration (BAC). For drivers under 21 the rule is simpler still: not a drop.
According to the handbook, alcohol and impairing drugs are involved in about 40 percent of crashes in which someone is killed. The only safe plan is never to drive after drinking or using drugs.
By the end of this topic you can
- You can state the BAC limits for adult, commercial and under-21 drivers.
- You can explain the Not-a-Drop law and what it costs a young driver.
- You can describe what happens if you refuse a chemical test.
- You can plan safe ways home that never involve impaired driving.
What you need to know and understand
- The adult limit is 0.05 BAC (0.04 for commercial drivers), and you can be charged below it if you are unsafe to drive.
- Under 21, driving with any measurable alcohol means 6 months' loss of driving privileges for a first offense.
- A second Not-a-Drop offense within 10 years means 2 years or until age 21, whichever is longer.
- A first DUI for a driver 21 or older brings a 120-day suspension; a second brings 2 years.
- Refusing a chemical test means an 18-month revocation for a first refusal; under 21 it is 2 years or until 21, whichever is longer.
- A first DUI brings an 18-month ignition interlock restriction, or 3 years if you were under 21 when arrested.
- A BAC of 0.16 or more counts as Extreme DUI with heavier penalties.
How alcohol and drugs affect driving
Impairment starts with the first drink. Alcohol slows reaction time, dulls judgment and blurs vision; the handbook says vision is affected from 0.02 BAC. Illegal drugs, over-the-counter medicines and prescribed drugs, including medical cannabis, can impair you in the same ways, and mixing them with alcohol is unpredictable. Utah law also treats driving with a measurable amount of certain controlled substances or their metabolites in your body as an offense, so read medicine labels and ask your doctor or pharmacist before driving.
Under 21: the Not-a-Drop rules
- It is illegal to buy, possess or drink alcohol under 21.
- Any measurable alcohol while driving means losing your driving privilege, even if you do not yet hold a license.
- To reinstate after a Not-a-Drop suspension you need a substance abuse assessment, or proof of completing a Prime For Life DUI class.
- A court conviction for underage drinking or possession can also suspend your license for 1 year (2 years for a repeat offense).
Implied consent and longer-term restrictions
By driving in Utah you agree to take a breath, blood, urine or oral fluid test if an officer asks. Refusing costs more than failing: a long revocation and a 2-year interlock restriction. After any alcohol-related action you also become an alcohol-restricted driver for 2 to 10 years, or for life after automobile homicide or felony DUI. During that time, driving with any measurable alcohol means a 1-year revocation. A deeper guide to Utah's 0.05 limit and the Not-a-Drop law is available on this site.
Common mistakes
- Thinking one drink is fine at 20. Under 21, any measurable alcohol breaks the law.
- Believing that waiting for your BAC to drop below 0.05 makes you safe. You can still be charged if you are impaired.
- Assuming prescribed or medical cannabis use is always safe to drive on. If it impairs you, do not drive.
- Refusing the test to avoid a DUI. Refusal brings a longer revocation on its own.
Test yourself: Drunk and drugged driving laws in Utah
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Sources: Utah Driver Handbook, 2026 edition (Utah Department of Public Safety, Driver License Division). Independent guide, not affiliated with any licensing agency. Always check the latest official rules with the Utah licensing agency.