Smog Check 101

How Often Do You Need a Smog Check in California?

Smog checks aren't on a fixed annual schedule for every driver. It depends on your vehicle's age, renewal cycle, and whether ownership is changing.

The common triggers

• Biennial renewal: most vehicles need a smog check every other year as part of the standard renewal cycle.
• Change of ownership: buying or selling a used vehicle in California typically requires a current smog certificate as part of the title transfer.
• Bringing a vehicle into California: Bringing a vehicle into California? We handle the out-of-state smog inspection the state requires.
• STAR-directed retest: if your vehicle is flagged for a directed retest, see our STAR station guide for what that means.

Vehicles that are typically exempt

Newer vehicles (generally within their first several model years) and some other categories are exempt from smog checks at renewal, though a smog certificate may still be required at change of ownership. Your renewal notice from the state will always tell you exactly what's required for your specific vehicle. That notice is the authoritative source, not a general rule of thumb.

Special vehicle categories

We also test vehicles that fall outside the standard passenger-car cycle: Hybrid & Diesel, RVs, Trucks & Minivans, and Gross Polluter that need directed retesting.