California Smog Check Requirements
The California smog check requirements depend on your vehicle: most gas cars from 1976 and newer need biennial testing in 34 counties.
TL;DR
- Biennial: most 1976-and-newer gas, hybrid, and alt-fuel vehicles need a smog check every 2 years. Your DMV renewal notice says “Smog Certification Required” when it’s due this cycle.
- Change of ownership: the seller must give the buyer a smog certificate from a test done within 90 days of the transfer (family transfers excepted).
- First California registration: always requires a California smog check — the 8-year new-car exception does NOT apply.
- Diesels: 1998 and newer need biennial checks with NO 8-year or 4-year exceptions; 1997 and older are exempt.
- Fully exempt: 1975-and-older gas vehicles, electric vehicles, and motorcycles. Certificates last 90 days and are sent to the DMV electronically.
Which rules apply to you?
Tap your vehicle type, enter the model year, tap your situation — then press the button. We’ll apply California’s smog check rules to your exact case.
Select from each dropdown.
Vehicle Type
Model Year
Enter your vehicle’s model year
Your Situation
Estimates only, based on BAR and DMV rules in effect October 2026. Your renewal notice always has the final word.
The 3 triggers: when a smog check is required
1. Registration renewal (biennial)
Every 2 years, most covered vehicles need a smog check to renew registration. Your DMV renewal notice will say “Smog Certification Required” — or “…at a STAR station” if your vehicle is directed to STAR. No certification, no renewal: the DMV won’t complete it without the electronic result.
2. Change of ownership
When a vehicle changes owners, a smog check is required: the seller must provide the buyer a valid smog certificate from a test done within 90 days of the transfer. Gasoline vehicles 4 model years and newer skip the inspection (the buyer pays a small transfer fee instead). Transfers between immediate family members generally don’t need one.
3. First registration in California
Any vehicle registering in California for the first time — including out-of-state purchases and vehicles previously registered elsewhere — needs a California smog check first. Out-of-state certificates don’t count, and the 8-year new-car exception does NOT apply to first-time registrations.
Complete criteria by vehicle type
Here are the California smog check criteria at a glance — find your vehicle type and read across:
| Vehicle | Renewal (biennial) | Change of ownership | First CA registration |
|---|---|---|---|
| Gas / hybrid / alt-fuel, 1976+ | Every 2 yrs; vehicles 8 model years and newer pay the smog abatement fee instead | Seller provides a cert from a test within 90 days; vehicles 4 model years and newer exempt | Smog check required |
| Diesel 1998+ (≤14,000 lbs) | Every 2 yrs — NO model-year exceptions | Required — NO model-year exceptions | Smog check required |
| Gasoline 1975 and older | ✅ Exempt from smog checks entirely | ||
| Diesel 1997 and older | ✅ Exempt from smog checks entirely | ||
| Electric vehicles | ✅ Exempt from smog checks entirely | ||
| Motorcycles | ✅ Exempt from smog checks entirely | ||
| Diesel over 14,000 lbs GVWR | CARB’s Clean Truck Check applies — not the BAR smog program | ||
Exemptions at a glance
The short version — tap any card for the full exemptions guide, including the interactive exemption checker:
Where the biennial program applies
Per dmv.ca.gov, 34 California counties require biennial smog checks. A few more counties — including El Dorado, Placer, Riverside, San Bernardino, San Diego, and Sonoma — require smog only in certain ZIP codes:
The STAR program
What the inspection covers & what it costs
👁️ Visual inspection
Emissions control components are checked visually — the catalytic converter, O2 sensors, and other equipment must be present, connected, and unmodified.
⚙️ Functional inspection
The emissions control system is functionally tested — including the check-engine light. An illuminated check-engine light is an automatic fail, every time.
🔌 OBD check
Most 2000-and-newer vehicles get an on-board diagnostics computer scan for stored trouble codes and monitor readiness.
💨 Tailpipe test
Pre-2000 vehicles get a tailpipe emissions measurement. Per BAR, the whole inspection usually takes about 30 minutes.
New residents & out-of-state vehicles
📅 20 days to register
New residents must register their vehicles within 20 days of establishing California residency (Vehicle Code §4152.5). There is no grace period.
🔍 CA smog check + VIN inspection
A California smog check is required before registering — out-of-state smog certificates don’t count. A VIN inspection at the DMV is also required.
⚠️ 8-year exception doesn’t apply
The 8-year new-car exception does NOT waive the smog check for a first-time out-of-state registration, even for a brand-new vehicle.
Enforcement: no certificate, no registration
🚫 Registration hold
The DMV will not renew your registration without the required smog certification. Because results transmit electronically, the DMV knows the moment your vehicle passes.
⏱️ Temporary Operating Permit
If your vehicle failed its biennial test, a Temporary Operating Permit (TOP) can keep you legal: $50 nonrefundable fee, valid 60 days, only one per vehicle in a 2-year period. The fee is waived with a BAR Consumer Assistance Program Letter of Eligibility.
The smog check laws in California
California’s requirements rest on a few key laws, administered jointly by the California Air Resources Board (CARB), the Bureau of Automotive Repair (BAR), and the DMV. Together, these are the smog check laws California drivers live under:
- Health & Safety Code §44011 — the Smog Check Program itself (and the smog abatement fee authority).
- Vehicle Code §4000.1 — vehicle registration requires valid smog certification.
- AB 2289 — requires BAR to report on program performance.
California smog check requirements: FAQs
What are the California DMV smog check requirements for my car?
Most gasoline, hybrid, and alternative-fuel vehicles from model year 1976 and newer need a smog check every 2 years when renewing registration, plus when the vehicle changes ownership or is first registered in California. Diesel vehicles from 1998 and newer are also covered. Exemptions exist for 1975-and-older gas vehicles, 1997-and-older diesels, EVs, and motorcycles.
How often does California smog check law require a test?
Every 2 years (biennially) for most vehicles, tied to your registration renewal. Your renewal notice will say “Smog Certification Required” when it’s due that cycle. A smog check is also required on change of ownership and first California registration.
What are the California smog check rules for change of ownership?
The seller must provide the buyer with a valid smog certificate from a test done within 90 days of the transfer. Cars from a dealer must have passed within the past 2 years. Gasoline vehicles 4 model years and newer are exempt from the transfer smog check (the buyer pays a small smog transfer fee instead). Transfers between immediate family members generally don’t need a smog check.
What is the smog abatement fee and who pays it?
If your gasoline-powered vehicle is less than 8 model years old, you pay a smog abatement fee with your registration renewal instead of getting a smog inspection. (We never state the dollar amount here — it varies and published sources conflict; the exact fee is printed on your renewal notice.)
Do diesels follow the same smog check criteria?
No. Diesel vehicles from model year 1998 and newer must be smog checked, but the 8-year and 4-year model-year exceptions do NOT apply to diesels. Diesels 1997 and older are exempt, as are diesels over 14,000 lbs GVWR (those fall under CARB’s Clean Truck Check instead).
Is a smog check required to renew my registration?
If your vehicle is subject to the biennial program and your renewal notice says “Smog Certification Required,” yes — the DMV will not renew your registration without it. Vehicles 8 model years and newer pay the abatement fee instead.
What happens if I don’t get a smog check?
The DMV will not renew your registration. If your vehicle failed the biennial test, you can get a Temporary Operating Permit (TOP) — $50, valid 60 days — while you arrange repairs or CAP assistance. Only one TOP per vehicle in a 2-year period.
What counties require smog checks in California?
34 counties require biennial smog checks, including Los Angeles, Orange, Sacramento, San Francisco, Santa Clara, and Fresno. San Diego and San Bernardino are partial — smog is required only in certain ZIP codes. A few counties require smog only on change of ownership or first registration.
Do new residents need a smog check in California?
Yes. New residents must register their vehicles within 20 days of establishing residency, and a California smog check is required before registering. Out-of-state smog certificates do not count, and the 8-year new-car exemption does not apply to first-time out-of-state registrations.
Do I need a smog check if my car is a hybrid?
Yes. Hybrids follow the same California smog check rules as gasoline vehicles — 1976 and newer hybrids need biennial smog checks, with the 8-year (renewal) and 4-year (ownership change) exceptions. Only fully electric vehicles are exempt.
What is the STAR program in the California smog check law?
The STAR program began January 1, 2013, replacing the old Gold Shield and Test Only programs. STAR stations meet the Bureau of Automotive Repair’s higher performance standards and can inspect all vehicles, including high-polluting vehicles. Your renewal notice will say if you must use one.
How long is a California smog check good for?
The smog certificate is valid for 90 days. Results are sent electronically to the DMV, and the station gives you a Vehicle Inspection Report to keep.
Does the military get a smog check exemption?
No. The DMV states plainly that active-duty military and veterans still need smog inspections for their vehicles — there is no military exemption under California smog check rules.
What does the smog inspection actually check?
The inspection includes a visual check of the emissions control system, a functional inspection, an on-board diagnostics (OBD) check for most 2000-and-newer vehicles, and a tailpipe emissions test for pre-2000 vehicles. It usually takes about 30 minutes.
Where can I get a smog check?
Any licensed Smog Check station — test-and-repair, test-only, or STAR stations (if directed by your renewal notice). Use the BAR Auto Shop Locator to find one. Stations must give you an estimate and get your authorization before starting; prices aren’t regulated, so shopping around helps.
Related smog check guides
Find a licensed smog station
Use the official BAR Auto Shop Locator — never trust a random list; station certifications change.
Last verified against bar.ca.gov and dmv.ca.gov: October 15, 2026. Requirements change — confirm current rules with BAR or the DMV before your visit.