Last verified: March 2026

What Changed with Prop 207

Before Prop 207, Arizona had a de facto zero-tolerance approach where the mere presence of THC metabolites — which persist in the body for weeks after smoking weed — could support a DUI conviction. You could be convicted of DUI for cannabis you consumed days or even weeks earlier.

Prop 207 changed this fundamentally. The law now requires evidence of actual impairment "to the slightest degree," not just metabolite presence. This means prosecutors must demonstrate that the driver was actually impaired by cannabis at the time of driving, not simply that THC metabolites were present in their system.

No Per Se THC Limit

Unlike Colorado (5 ng/mL threshold), Arizona has no per se THC blood concentration limit. A 2021 proposal to set an extremely low 2 ng/mL limit failed to advance in the legislature. The impairment-based standard remains the sole legal framework.

How Enforcement Works

• Observation-based: Officers look for signs of impairment — erratic driving, bloodshot eyes, delayed reactions, and other behavioral indicators
• Field sobriety tests: Standard NHTSA field sobriety tests are administered
• Drug Recognition Experts (DREs): Specially trained officers may conduct detailed evaluations
• Blood testing: If arrested, a blood draw can be used to establish the presence and concentration of THC

Penalties

Cannabis DUI penalties are the same as alcohol DUI penalties in Arizona:

• First offense: Minimum 24 hours jail (up to 10 days), fines starting at approximately $1,250, license suspension, mandatory substance abuse screening
• Second offense: Minimum 30 days jail, increased fines, license revocation
• Extreme DUI: Enhanced penalties apply for high levels of impairment or accidents causing injury