Every California smog check term and question, plainly defined

How long is a California smog certificate valid?

It is valid for 90 days from inspection.

Per California DMV registration rules.

This entry also has a full Q&A treatment: smoganswers.com/q/how-long-is-a-california-smog-certificate-valid/

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Last reviewed 2026-05-25 · Cal Smog Network canonical answer library