# Arizona — Vehicle emissions testing: which counties require it, in which states

For Arizona, counties where testing is required is the Phoenix and Tucson metropolitan areas, verified against its source on 2026-08-18.

- **State:** Arizona _(our reading, not quoted from the source)_
- **Counties where testing is required:** the Phoenix and Tucson metropolitan areas _(verified: appears in the quote below)_

## What the source says

> Vehicle emissions testing is required in major metropolitan areas that are not meeting federal air quality standards for ozone and other pollutants. In Arizona, testing is required in the Phoenix and Tucson metropolitan areas, where ozone and particulate matter pollution are a problem.

## Source

- https://www.myazcar.com/

Last verified: 2026-08-18. Review by: 2027-08-18.
Part of [Vehicle emissions testing: which counties require it, in which states](https://referencesource.org/vehicle-emissions-testing-by-state/).