Before hiring: Drivers of commercial vehicles must always be drug tested before a motor carrier hires them, unless:
• the driver participated in a federally-approved drug testing program in the past 30 days
• was either
o tested for drugs in the past 6 months OR
o participated in a random drug program in the past 12 months
• no prior employer of the driver has knowledge or records of a drug violation in the past 6 months
If a motor carrier does not drug test a driver because it believes he or she is exempt, then the carrier must obtain and retain the name of the program, proof of participation, proof the program meets certain federal requirements, proof that the driver has not refused to be drug tested, and the date and results of any drug tests.
A motor carrier may, but is not required, to test for alcohol before hiring a driver.These regulations are found in Title 49 of the Code of Federal Regulations in Part 382.201.