The Substance Abuse Mental Health Services Administration (SAMHSA) www.SAMHSA.gov(formerly NIDA, National Institute of Drug Abuse) is the department of the federal government that regulates and certifies laboratories currently processing Department of Transportation (DOT) specimens. SAMHSA Laboratory Certification is the highest standard available and ensures the most accurate processing. These laboratories confirm all non-negative / positive employee drug screen samples by GC/MS testing. Laboratories with the SAMHSA certification are also available to test Non-DOT specimens.

SAMHSA is the organization that created the SAMHSA 5 which is a list of drugs for which DOT organizations are required to test. Many companies use the SAMHSA 5 as the minimum drug testing standard and add other drugs.