MO Emissions test

Jefferson County emissions test

Get the emissions requirement cleared before you renew in Jefferson County.

Last synced Mar 18, 2026, 7:18 AM UTC from official source .

Core Missouri emissions coverage is source-backed, but Missouri applies parity-year exemptions and county participation through the Gateway Vehicle Inspection Program while live station coverage remains delegated to the official finder.

What to know

Before you go

Testing required Yes This county can hold up renewal until you clear the test.

Typical fee Varies Fees vary by station or vehicle.

Gas vehicles Gas vehicles model year 1996 or newer Use this if the vehicle is gas, hybrid, or another covered light-duty type.

Diesel vehicles Diesel vehicles model year 1997 or newer • up to 8,500 pounds GVWR Use this if the vehicle is diesel-powered.

Exemptions

motor vehicles and RVs with a manufacturer's gross vehicle weight rating over 8,500 pounds
new motor vehicles on an MSO during the 4-year period following the model year when the odometer is under 40,000 miles and Missouri grants the waiver
1995 and older gasoline vehicles and 1996 and older diesel vehicles
motor vehicles driven fewer than 12,000 miles between biennial safety inspections when the mileage waiver is approved
vehicles registered in an affected county but based and operated outside the testing area for at least 24 months when the out-of-area waiver is approved

Stations

Official inspection station finder

Find a station

Missouri publishes Jefferson County emissions coverage through the Gateway Vehicle Inspection Program, but live station availability is delegated to the official station finder.

Use the official station finder for live locations.

Do this now

Finish emissions first

Open the official station finder or official county rule.
Complete the test or waiver step that applies to your vehicle.
Go back to Missouri renewal once the requirement is cleared.

Find a station Open Missouri renewal