According to the California Department of Motor Vehicles, all vehicles (there are exceptions) are required to receive a smog check and certificate of inspection. The smog check is required biennially, or every two years. There are a few exceptions, however. If your vehicle is four or less model years old, you don't need a smog certification. If you're transferring it to a family member, you don't need a smog check. Finally, if you submitted the smog certification 90 days prior to transference, you can forgo the check. If your car is less than six model years old, you can pay a smog abatement fee for the first six registration years. After the six years are up, you'll need to get a smog check.