How often you need a smog check depends on your state, your car's age, and sometimes where you live within that state

There is no single answer because emissions testing rules are set by individual states, not the federal government. California requires smog checks every two years for most vehicles, but every year for cars older than 1975. Texas has no statewide requirement at all, though some counties do. New York tests every two years. The Northeast has its own regional program called the Vehicle Inspection Program (VIP), which includes Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, and Vermont — each with slightly different intervals and rules.

Your vehicle registration renewal notice will tell you whether a test is due. Some states print the test important date right on the registration card; others send a separate notice. If you are moving to a new state or buying a car there, check your state's Department of Motor Vehicles website or call your local emissions testing station before your registration expires, because driving without a current smog check when one is required can result in a registration hold or fine.

Key Takeaways

  • Most states that require smog checks do so every two years, but California, some Northeast states, and a few others test annually for older vehicles.
  • Your registration renewal notice will state whether a smog check is due — do not assume based on when you last tested.
  • Some states exempt new cars for the first three to five years, and some exempt hybrid or electric vehicles entirely.
  • If you fail a smog check, you typically have 30 to 60 days to repair the vehicle and retest at no additional fee.
  • Driving with an expired or failed smog check when one is required can prevent you from renewing your registration.

States that require smog checks and their testing intervals

California requires smog checks every two years for vehicles model year 1976 and newer, except those six years old or newer, which are exempt. Vehicles older than 1975 must test every year. Heavy-duty trucks and motorcycles have separate rules. If you live in a California county with poor air quality, you may face stricter testing or additional requirements.

The Northeast regional program covers ten states with similar but not identical rules. Most test every two years, but some states exempt vehicles under a certain age — typically five to eight years old. New York and Connecticut, for example, test every two years but exempt vehicles under six years old. Maine and New Hampshire have different age cutoffs. Check your specific state's DMV website because the exemption age varies.

Other states with statewide requirements include Colorado, Georgia, Illinois, Indiana, Kentucky, Louisiana, Maryland, Missouri, Nevada, New Mexico, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, and Washington. Most test every two years. Some exempt new vehicles for three to five years. A few states, including Georgia and Illinois, exempt hybrid and electric vehicles. Colorado exempts vehicles model year 2007 and newer.

States with no statewide requirement include Texas, Florida, Arizona, and many others. However, some counties or metropolitan areas within these states do require testing — for example, certain counties in Texas and the Phoenix area in Arizona. If you live in a state without statewide testing, check whether your county has a local requirement.

What happens if your car is new or you just bought it

Most states exempt newly purchased vehicles from smog checks for a set period. In California, new cars are exempt for six years. In the Northeast, exemptions typically run three to eight years depending on the state. This exemption applies to the model year of the vehicle, not the date you bought it — a car manufactured in 2022 that you buy in 2024 is still within the exemption window in most places.

If you buy a used car from out of state and register it in a state with smog check requirements, you will usually need to test it before or shortly after registration, even if it is relatively new. Some states allow a grace period of 30 to 60 days after you register the vehicle; others require the test before registration is complete. Check your state's DMV website or call your local testing station when you register the car.

What to do if you fail a smog check

A failed smog check means your vehicle's emissions are above the legal limit for one or more pollutants — usually nitrogen oxides, particulate matter, or hydrocarbons. The test report will identify which pollutant exceeded the standard. You are not required to repair the vehicle when ready, but you cannot renew your registration until you pass.

Most states give you 30 to 60 days to repair the vehicle and retest. The retest is usually free or costs a small fee, and you do not need to pay for a new smog check if you pass the retest within the allowed window. Common repairs for failed smog checks include replacing a faulty oxygen sensor, fixing a vacuum leak, replacing a catalytic converter, or updating engine software. If repairs are expensive, some states offer Repair information Programs or Vehicle Retirement Programs that help low-income owners repair or replace vehicles that repeatedly fail.

If you cannot afford repairs and your vehicle is very old, California and a few other states allow you to retire the vehicle through a state program in exchange for a small payment or tax credit. This is different from a smog check waiver — waivers are rare and only explore if you have already spent a certain amount on repairs without passing.

How to find a smog check station and schedule a test

Your state's DMV website lists certified smog check stations. In California, you can search by ZIP code on the Bureau of Automotive Repair website. In the Northeast, each state maintains its own list of inspection stations. You do not need an appointment at most stations — you can drive in and test the same day, though wait times vary. The test itself takes 10 to 30 minutes.

Bring your vehicle registration and a valid ID. Some stations require proof of insurance. The cost varies by state and station but typically ranges from $30 to $80. A few states set a maximum fee; others allow stations to charge what they want. Call ahead if you want to know the exact price.

Before you go, make sure your vehicle is in reasonable condition. If your check engine light is on, the test will likely fail because the vehicle's onboard diagnostic system is not clear. If you have a slow leak or other minor issue, get it fixed first — it is cheaper than failing and retesting.

Exemptions for electric and hybrid vehicles

Several states exempt electric vehicles from smog checks entirely because they produce zero tailpipe emissions. California, Colorado, Georgia, Illinois, and others on their lists do not require testing for battery electric vehicles. Plug-in hybrids are sometimes exempt and sometimes required to test — rules vary by state.

Traditional hybrids that use both a gas engine and electric motor are usually required to test in states that have smog check programs, because they still produce emissions when the gas engine runs. Check your state's DMV website to confirm the status of your specific vehicle type.

What to do if you move to a new state

When you register your vehicle in a new state, you must follow that state's smog check rules, not your old state's. If you move from a state with no smog check requirement to one that has it, you will need to test your vehicle before or shortly after registration. If you move from a state with frequent testing to one with less frequent testing, your old test does not count — you start fresh with the new state's schedule.

Some states allow a grace period of 30 to 90 days after you register to complete your first smog check. Others require it before registration is finalized. Call your new state's DMV or a local testing station to confirm the timeline before you register the vehicle.

Frequently Asked Questions

Can I get a smog check waiver if my car keeps failing?

Waivers are rare and only available in a few states like California. To may have access to, you usually must have spent $500 to $1,000 on repairs over two consecutive test cycles without passing. Even then, a waiver is temporary — you still cannot renew registration indefinitely. Ask your testing station or state DMV whether a waiver program exists in your state.

What if I do not have a smog check when my registration expires?

You cannot renew your registration without a passing smog check in states that require one. Your registration will expire, and driving with an expired registration can result in a traffic stop and fine. Some states allow you to renew online or by mail if you schedule a smog check within a certain window, but this varies. Contact your DMV when ready if your registration is about to expire.

Do I need a smog check if I am selling my car?

Rules vary by state. California requires a smog check before you transfer ownership. Many other states do not require it for sale but do require the buyer to test before registering the vehicle in their name. Check your state's DMV website or ask the buyer's registration office what is required.

How long does a smog check take?

The actual test takes 10 to 30 minutes. Wait time at the station depends on how busy it is — some stations have no wait, others may have a line. Call ahead or check online reviews to see typical wait times at stations near you. Plan for 30 to 60 minutes total if you are going during peak hours.

What if my vehicle is too old to test?

Most states test vehicles model year 1975 and newer. Vehicles older than that are usually exempt from smog checks. Some states have a cutoff at 1968 or 1970 instead. Check your state's rules, but if your vehicle is significantly older than 1975, it likely does not need to test. Confirm with your DMV or a local testing station.