Emissions testing is mandatory in Phoenix and Tucson, but not in the rest of Arizona. If you reside in either Phoenix or Tucson, you are required to undergo an emissions test every two years while renewing your vehicle registration. On the other hand, car safety inspections are not mandatory in the state of Arizona.
All vehicles must pass annual safety and emissions inspections at DMV-approved stations. Vehicles that fail can be re-inspected for free within 60 days. Upon passing, a sticker is issued to indicate the vehicle's compliance.