How Often Do You Need a Smog Check in California?

One of the most common questions we receive at Lake Smog Test Only is: "How often do I need to get a smog check?" The answer depends on several factors, but for most California drivers, the requirement is straightforward. Here's a complete breakdown.

Every Two Years (Biennial Requirement)

The standard smog check schedule in California is every two years, coinciding with your DMV registration renewal. You'll know it's time when your DMV renewal notice includes a statement that says: "A smog certification is required for this registration renewal."

Not every renewal year requires a smog check—the DMV alternates. One renewal you'll need a smog check; the next, you won't. Your renewal notice will always clearly state whether a smog check is required.

Change of Ownership

Whenever a vehicle changes hands through a private sale, the seller is required to provide the buyer with a valid smog certificate. This is true even if the vehicle recently passed a smog check for registration purposes. A smog certificate is valid for 90 days from the date of the test.

Note: Dealership sales are handled differently—the dealer typically takes care of the smog certification before the sale.

Out-of-State Vehicle Registration

If you're moving to California from another state, your vehicle will need a smog check before you can register it with the California DMV. This applies regardless of the vehicle's age (unless it falls under an exempt category).

STAR Directed Vehicles

Some vehicles are flagged by the DMV as "directed" to a STAR station. This means the vehicle must be tested at a station that holds STAR certification—like Lake Smog Test Only. Vehicles are typically directed to STAR stations if they:

• Have a history of high emissions
• Were previously identified as gross polluters
• Are selected through the DMV's random selection program

Your DMV renewal notice will specify if you need a STAR station.

When You DON'T Need a Smog Check

• Your vehicle is less than 8 model years old (new vehicle exemption, though you'll pay a smog abatement fee)
• Your vehicle is a fully electric vehicle
• Your vehicle is model year 1975 or older (gasoline) or 1997 or older (diesel)
• Your DMV renewal notice does not mention a smog check requirement

How Long Is a Smog Certificate Valid?

A smog certificate is valid for 90 days from the test date. If you're planning ahead for a registration renewal or vehicle sale, make sure to time your smog check accordingly so the certificate doesn't expire before you need it.

Quick Summary

• Registration Renewal: Every 2 years (when your renewal notice says so)
• Change of Ownership: Seller must provide a certificate (valid 90 days)
• Out-of-State Registration: Required before registering in California
• Certificate Validity: 90 days from test date

Still not sure if your vehicle needs a smog check this year? Give us a call at (626) 798-0049 or just stop by. Walk-ins are always welcome!