Welcome to the New Hampshire OBD & Safety Testing (NHOST) Program web site!

The annual vehicle inspection process in New Hampshire includes an On-Board Diagnostic (OBD) test along with the Safety inspection. This website provides information to help motorists understand the inspection process and NHOST Program.

On October 1, 2007, the State of New Hampshire transitioned into the final stage of the OBD emission program. All automobiles and light-duty trucks whose model year is 20 years old and newer must now pass an OBD emission system inspection during its inspection period. Rejected vehicles will be required to be repaired and re-tested to verify repairs before an inspection sticker will be issued.

Vehicles must pass an emission system test to ensure they are running as clean and efficiently as possible. This will help maintain good air quality, making it cleaner for everyone enjoying the scenic public ways of New Hampshire.


The impact of automobiles on air quality is clear. You can help minimize your vehicle's contribution to the problem by keeping it properly maintained and tuned. The New Hampshire OBD testing program helps by notifying vehicle owners when a problem with the emission control system is detected.

NH Inspection Stations