The Missouri vehicle inspection process is overseen by the state Highway Patrol under the Department of Public Safety (DPS). However, the emissions testing program is overseen by the Gateway Vehicle Inspection Program (GVIP) under the Inspection and Maintenance Section of the Department of Natural Resources (DNR).

There are other important differences between smog tests and safety inspections in Missouri. In most cases, drivers must complete a car inspection during their vehicle registration renewal period, but only vehicles registered in certain parts of the state must undergo a test for emissions. Whenever a smog check or safety inspection is due, the state sends residents a reminder in the mail. To learn more about MO safety and emissions inspections, review the sections below.

Missouri Emissions and Smog Check Requirements

Vehicle emissions testing in Missouri is only a requirement prior to completing vehicle registrations in the city of St. Louis and the following counties:

  • Jefferson
  • Franklin
  • Louis
  • Charles

When completing a test at a smog check station, the inspector uses onboard diagnostics testing (OBDII) to check a vehicle for issues. Drivers must complete an emissions test if their vehicle meets any of the following:

  • The vehicle weighs less than 8,500 lbs.
  • The vehicle is gas-powered and was built after 1996
  • The vehicle is diesel-powered was built after 1997.

As a reminder to complete the DMV smog check on time, the Department of Revenue (DOR) sends drivers a notice in the mail at least 60 days before a vehicle’s license plate is set to expire. Additionally, vehicles must undergo an emissions check whenever there is a transfer of ownership. 

Note: Drivers receive a vehicle inspection report and a windshield sticker after their vehicle as passed checks. Drivers must register their vehicles within 60 days of completing the inspection.

Additionally, drivers must complete a car safety inspection in MO whenever a vehicle changes ownership or within 60 days of applying for vehicle registration. In many cases, law enforcement requires vehicles to undergo an inspection after a traffic accident as well. During the DMV safety inspection, the state tests the following items for compliance:

  • Seat belts
  • Rearview mirrors
  • Windshield wipers
  • Horn
  • Turn signals, taillights and brake lights
  • Headlights
  • Steering mechanism
  • Brake system
  • Tires and wheels
  • Exhaust system
  • Bumpers
  • Fuel system

When completing a car inspection, drivers only need to provide the inspector with the vehicle and payment for testing fees. If drivers do need to submit their current inspection certificate, the renewal notice will say so.

Smog Check Exemptions in Missouri

Vehicle owners only need to obtain a smog certification in MO if they register their vehicles in the five regions requiring testing, including the St. Louis area. Additionally, testing exemptions are allowed for the following vehicles:

  • A brand-new vehicle with an odometer reading of less than 6,000 miles at the time of sale.
  • Electric or plug-in hybrid vehicles.
  • Gas-powered vehicles manufactured before 1995 or diesel vehicles built before 1996.
  • Motorcycles and motor tricycles.
  • School buses, military vehicles, historic vehicles and kit cars.
  • Vehicles that do not contain an onboard diagnostic system.

Furthermore, an eligible driver who needs to perform emissions testing may apply for a Mileage-Based Exemption (Form 780-1972). To qualify for an exemption, vehicles must be less 4 years old and the owner must have driven the vehicle less than 12,000 miles within the previous 2 years. Additionally, vehicles under 2 years old may qualify if the odometer reads less than 40,000 miles.

Note: Cars must undergo a vehicle safety inspection every 2 years, even if an emissions test is not required. However, car inspection exemptions apply to vehicles manufactured within the past 5 years, those sold from dealer-to-dealer or cars sold for junk or salvage.

Out-of-State Emissions Testing in Missouri

If you need to complete an emissions inspection in Missouri but are temporarily out-of-state, you may complete the test in another state by completing a Reciprocity Request (Form 780-2192) or a DOR Affidavit (Form 768). You must complete an auto emissions testing Reciprocity Request if your vehicle is in a state that performs OBDII testing and does not need to complete a safety test.

However, you must complete a DOR Affidavit if you need to complete a safety inspection as well. When completing the DOR Affidavit, you must check box three, which allows you to complete the safety and smog test within 10 days of returning to Missouri.

Note: If you need to complete an inspection but not an emissions test while out-of-state, you may register your vehicle with the DOR while in another state, as long as you complete your safety inspection within 10 days of returning to Missouri.

Emissions Waivers in Missouri

There are no vehicle safety inspection waivers for motorists to obtain, but drivers may request the following waivers for emissions tests:

  • Cost-Based
  • Estimate-Based
  • Out-of-Area

To qualify for a Cost-Based emissions inspection waiver, motorists must spend between $200 and $450 on emissions-related repairs. To qualify for an Estimate-Based waiver, the vehicle must need at least $450 worth of emissions-related repairs. Alternatively, vehicle owners who need to perform vehicle smog testing in Missouri but are temporarily out-of-state may obtain an Out-of-Area waiver.

Vehicle owners must send all forms for car smoke test waivers to the following address:

Missouri DNR
Gateway Vehicle Inspection Program
7545 S. Lindbergh, Suite 210
St. Louis, MO 63125

Testing Fees in Missouri

The smog test price in Missouri is $24, while the price of completing a safety inspection is $12 for passenger vehicles or trucks and $10 for motorcycles. Vehicle owners receive one free re-inspection after failing the initial test if they retest the vehicle within 20 business days. However, drivers must retest the vehicle at the same testing station to receive the retest at no charge.

Where to Perform an Emissions Check in Missouri

Drivers may complete emissions testing in Missouri at licensed auto shops in the St. Louis area. If drivers need to complete both a safety and smog check in the St. Louis region, vehicles may undergo both tests during the same visit, but car owners must verify this with the specific testing station.

In most cases, a shop will display a GVIP sign and an Official Vehicle Inspection Station sign if the facility can perform both tests. However, drivers must contact the testing station to confirm this before heading in.

Note: If drivers need to perform a car inspection for safety purposes but not a car smoke test, then they must visit any one of the state’s 3,491 authorized repair shops or garages displaying a yellow inspection station sign. Many new-car dealerships also perform safety inspections.

Failing a Missouri Smog and Emissions Test

If a vehicle fails its MO emissions check, vehicle owners must bring their vehicle to a state-recognized repair station (MRRT) to complete all necessary car repairs before retesting the vehicle. To qualify for a smog inspection waiver, however, car owners must bring the vehicle to a repair technician who can apply diagnostic costs and labor toward the waiver’s minimum amount.

Additionally, motorists must provide the repair technician with the vehicle inspection report and repair data sheet, which the state issues after completing the initial test. When retaking the emissions test, drivers must submit the inspection report and completed repair data sheet.

If a vehicle fails its safety inspection, motorists must perform all necessary car repairs before they may drive the vehicle or complete a retest. However, drivers may operate their vehicles for repair or inspection-related purposes.

Last updated on Tuesday, March 10 2020.