What Is the Legal BAC Limit in Arizona?

The four thresholds

• .08 — the standard adult limit: an alcohol concentration of .08 or more within two hours of driving is DUI, regardless of visible impairment
• .04 — the limit for commercial license holders driving a commercial vehicle
• Any alcohol at all — drivers under 21, under Arizona’s zero-tolerance rule
• .15 and .20 — the extreme and super extreme tiers, which sharply raise the mandatory jail attached to the same misdemeanor

The thresholds live in A.R.S. § 28-1381 and § 28-1382. The two-hour language matters: the State must tie the concentration to the window after driving, which makes the timing of the blood or breath test a genuine issue rather than a formality.

Why “under the limit” does not mean safe from charges

Arizona separately makes it unlawful to drive while impaired to the slightest degree — no number required. Prosecutors charge it alongside the .08 count, and it is how a .06 driver who performed poorly on field sobriety tests still ends up with a DUI case. The number is one path to a charge, not the boundary of one.

Zero tolerance under 21

A driver under 21 can be charged with any spirituous liquor in their body while driving — a .02 reading is enough. License consequences attach on top of the criminal exposure, and for students the record itself is usually the costliest part. These cases are defensible on the same grounds as any DUI: the stop, the testing, and the timeline.

Wherever your reading fell, the number on the citation is the State’s claim, not a verdict — calibration records, testing procedure, and the two-hour window all get examined. That work is described on our DUI defense page, and if this is your first charge, start with what a first-offense DUI actually involves.