How are truck drivers drug tested?

The first time you're caught, you lose your CDL for three months. You'll also lose your job, and the reason (CDL suspended due to positive drug test) is recorded on your DAC report if you're with a company that is a DAC member. Any other trucking company that subscribes to DAC is going to see it.

The second time, you lose it for a year. The third time, you can never get another CDL.