Do classic cars need a smog check in California?

Only if it is model year 1976 or newer (gasoline) or 1998 or newer (diesel) — older classics are exempt.

• 1975-and-older gasoline classics: exempt, no inspection at registration
• 1976-and-newer classics: same biennial smog check as any car
• Engine or emissions modifications must be CARB-approved (EO number) to pass
• The cutoff is fixed by model year — no rolling exemption since 2005

Per BAR (bar.ca.gov/smog-check) and CA Health & Safety Code §44011.