Arizona's emissions testing requirement and who must comply
Arizona requires emissions testing for most vehicles registered in Maricopa, Pima, and Pinal counties — the state's three most populated areas. The Arizona Department of Transportation (ADOT) does not run the tests themselves. Instead, the state contracts with private testing facilities, and you choose which one to visit. The test checks whether your vehicle's exhaust meets federal Clean Air Act standards.
You must test your vehicle every two years if you live in one of the three affected counties. Vehicles registered outside those counties do not need to test. If you move into a testing county, you have until your next registration renewal to complete a test. Diesel vehicles, motorcycles, and vehicles model year 1975 and older are exempt.
New vehicles — those model year current or one year old — do not need to test for their first two years of registration. After that, the two-year cycle begins. If you buy a used vehicle, the testing requirement depends on when it was last tested and registered, not when you purchased it.
Key Takeaways
- Emissions testing is required every two years in Maricopa, Pima, and Pinal counties only; ADOT contracts with private test facilities rather than running tests directly.
- You can choose any state-certified testing facility, and the test takes about 10 to 15 minutes and costs between $20 and $30 depending on the facility.
- Your vehicle must pass the test before you can renew your registration; if it fails, you have 30 days to repair it and retest at no additional charge.
- You can schedule a test online through the ADOT website or call a facility directly; no appointment is always required, but scheduling ahead reduces wait time.
- If your vehicle fails and repairs are too expensive, you may be able to request a waiver, but only after two failed tests within a 12-month period.
Finding and scheduling a test at a certified facility
ADOT maintains a searchable list of certified testing stations on its official website. You can filter by county and city to find facilities near you. Each station is independently operated but must follow state testing procedures and equipment standards. Facilities typically operate during standard business hours, though some offer extended evening or weekend appointments.
You do not need an appointment at most facilities — you can walk in and wait your turn. However, calling ahead or scheduling online through a facility's website can reduce your wait time, especially during peak renewal periods (the month before your registration expires). Some facilities use online scheduling systems; others take phone reservations.
Bring your vehicle registration and a valid photo ID. The test itself takes 10 to 15 minutes. The technician will connect your vehicle to a dynamometer or tailpipe analyzer, depending on the facility's equipment, and measure emissions output against state standards.
What happens if your vehicle fails the test
If your vehicle fails, you receive a detailed report showing which emissions standards it did not meet. The report identifies the likely cause — often a faulty oxygen sensor, catalytic converter problem, or engine control issue. You have 30 days from the test date to repair the vehicle and retest at the same or a different facility.
The retest is free if you return within 30 days. You do not need to wait for repairs to be completed before retesting; some owners retest when ready after a repair to confirm the fix worked. If the vehicle passes the retest, you can proceed with registration renewal.
If you fail a second time within 30 days, you can continue retesting at no charge as long as you stay within the original 30-day window. After 30 days, a new test costs the standard fee. If your vehicle fails three times in a row, you may be may be able to access for a repair cost waiver, though this requires meeting specific income and repair cost thresholds.
Repair cost waivers and hardship options
If your vehicle fails the test and repairs would cost more than a certain threshold — the amount varies by vehicle model year and type — you may be able to request a waiver. To may have access to, you must have failed the test at least twice within a 12-month period, and the estimated repair cost must exceed the state's threshold for your vehicle class.
Waivers are not automatic. You must submit a repair estimate from a certified mechanic to ADOT or the testing facility. The estimate must be on the mechanic's letterhead and include a detailed breakdown of parts and labor. ADOT reviews the estimate and decides whether the cost justifies a waiver.
If approved, a waiver allows you to register your vehicle for one additional year without passing the test. You will still need to test again at your next renewal. Waivers do not exempt you permanently; they are a one-time hardship measure.
Renewing your registration after passing the test
Once your vehicle passes the test, the facility sends the results electronically to ADOT. You can then renew your registration online through the Arizona Motor Vehicle Division website, by mail, or in person at a Motor Vehicle Division office. You do not need to bring the test results yourself — ADOT has them on file.
Registration renewal can be completed at the same time as the test or afterward. Many people test first, then renew registration once they have a passing result. If your registration expires before you test, you cannot legally drive the vehicle, so plan ahead if your renewal date is approaching.
Registration renewal fees vary based on vehicle type and weight. The emissions test fee is separate and paid directly to the testing facility, not to ADOT.
Special situations: out-of-state moves, temporary registration, and exemptions
If you move to Arizona from another state, your vehicle must be tested before you register it in one of the three testing counties. If you move out of a testing county to a non-testing area, you no longer need to test. If you move between testing counties, your testing schedule does not change — you still test every two years from your last test date.
Temporary registration permits do not exempt you from testing. If you purchase a vehicle and receive a temporary permit while waiting for permanent registration, you must still complete an emissions test before the permit expires if you live in a testing county.
Vehicles registered to the military, government agencies, or used for commercial purposes may have different rules. Check with ADOT or your local Motor Vehicle Division office if your vehicle falls into one of these categories.
Frequently Asked Questions
Can I test my vehicle before my registration expires?
Yes. You can test up to 90 days before your registration expires. The test results are valid for two years from the test date, so testing early gives you flexibility in when you renew registration. However, your registration must still be current to legally drive the vehicle.
What if I fail the test and cannot afford repairs?
If repairs exceed the state's cost threshold and you have failed twice in 12 months, you can request a waiver. You will need a repair estimate from a certified mechanic. A waiver allows you to register for one more year without passing, but you must test again at the next renewal.
Do I need to test if I only drive my vehicle occasionally?
If your vehicle is registered in Maricopa, Pima, or Pinal county, you must test every two years regardless of how often you drive it. The requirement is based on registration location, not usage. If you do not plan to drive the vehicle, you can let the registration expire instead.
What if the testing facility gives me conflicting results?
Testing procedures are standardized, but equipment can vary slightly between facilities. If you believe a result is incorrect, you can retest at a different certified facility. If the second test passes, you can use that result for registration. If both fail, the second result stands.
Are electric or hybrid vehicles required to test?
Electric vehicles do not produce tailpipe emissions and are exempt from testing. Hybrid vehicles that have a gas engine must test like any other gas-powered vehicle, even if they spend most time running on battery power.