What Is the Legal Alcohol Limit for a DUI in Arizona?

What Is the Legal Alcohol Limit for a DUI in Arizona?

The number everyone knows is 0.08 — under A.R.S. § 28-1381(A)(2), it is unlawful to drive or be in actual physical control of a vehicle with an alcohol concentration of 0.08 or more within two hours of driving. But treating 0.08 as “the legal limit” is one of the most dangerous misunderstandings in Arizona law, because you can be convicted of DUI in Arizona below 0.08, and the penalties escalate sharply at higher numbers.

You Can Be Charged Under 0.08: “Impaired to the Slightest Degree”

Arizona’s primary DUI provision, 28-1381(A)(1), has no number in it at all. It prohibits driving while impaired by alcohol or drugs “to the slightest degree” — the strictest impairment standard in the country. A driver at 0.05 or 0.06 who shows signs of impairment can be, and regularly is, charged with DUI in Arizona. The BAC number is evidence, not a safe harbor.

Several groups face even stricter numbers:

• Commercial drivers: 0.04 in a commercial motor vehicle under 28-1381(A)(4);
• Rideshare and for-hire drivers: a separate provision applies to driving a vehicle for hire;
• Drivers under 21: Arizona’s zero-tolerance approach means any alcohol can cost an underage driver their license.

The BAC Tiers: Where the Penalties Jump

Above 0.08, Arizona’s DUI penalties climb in defined steps under A.R.S. § 28-1382:

• 0.08 to 0.149 — standard DUI: mandatory minimum 10 consecutive days jail (a judge may suspend all but 1 day with completed alcohol screening/treatment);
• 0.15 to 0.199 — Extreme DUI: mandatory minimum 30 consecutive days (reducible to 9 with a 12-month ignition interlock);
• 0.20 and above — Super Extreme DUI: mandatory minimum 45 consecutive days (reducible to 14 with the interlock).

Every tier also brings fines and assessments, license consequences, an ignition interlock requirement, and traffic survival school — and repeat offenses within 84 months escalate dramatically. For the full jail-time picture, see our guide to whether you can go to jail for a DUI in Arizona.

How the Number Gets Measured, and Challenged

The State’s number comes from a breath or blood test, and neither is beyond challenge. Breath machines require strict calibration, maintenance, and operator procedure; blood draws require proper collection, storage, and lab analysis with an intact chain of custody. Margin-of-error arguments matter enormously at the tier boundaries: the difference between 0.079 and 0.081, or 0.149 and 0.151, is the difference between charges — and between 1 day and 30 days of mandatory jail. Refusing a test triggers its own consequences under Arizona’s implied consent law — see our guide to refusing a blood draw in Arizona.

How Tamou Law Group Defends BAC Cases

We litigate the number. At the tier boundaries, 0.08, 0.15, 0.20, margin of error, rising BAC, and instrument reliability are not technicalities; they are the difference between charges and between mandatory minimums. We pull the calibration records, retest where possible, and model the timeline, while positioning eligible clients for every statutory reduction.

Start with our Arizona DUI defense guide, then see Extreme DUI and Super Extreme DUI for the higher tiers, and can I go to jail for a DUI? for sentencing. Call 623-321-4699, 24/7.