Drug tests in the United States can be divided into two general groups, federal mandated and general workplace. Federal mandated drug testing started when President Ronald Reagan enacted via executive order, that federal workers refrain from using illegal substances. Subsequent federal legislation required drug testing within the executive branch of government as well as “safety sensitive” occupations within the trucking, mass transit, rail, airline, marine, and oil and gas pipeline sectors. Drug testing guidelines and processes, for federally mandated drug testing, are established and regulated (by the Substance Abuse and Mental Health Services Administration/ SAMHSA, formerly under the direction of the National Institute on Drug Abuse / NIDA. Referred to as the NIDA-5, or standard SAMHSA five panel test, the laboratory based urine test includes marijuana, opiates (codeine and heroin), amphetamine/methamphetamine, and PCP. Unfortunately, these test classes were established decades ago, with little major revision, and do not account for current drug usage patterns. For example, SAMHSA / DOT tests exclude semi-synthetic opioids, such as oxycodone, oxymorphone, hydrocodone, hydromorphone, etc., and other prescription pain medications widely abused in the United States.

While SAMHSA/NIDA guidelines only allow laboratories to report quantitative results for the “NIDA-5″ on their official NIDA tests, many drug testing laboratories and on-site tests now offer a wider or “more appropriate” set of drug screens which may be more reflective of current drug use patterns. As noted above, these tests include semi-synthetic pain killers such as Oxycodone (Oxycontin, Percocet), Oxymorphone, Hydrocodone (Vicodin), Hydromorphone; benzodiazepines (Valium, Xanax, Klonopin, Restoril) and barbiturates.

Other drugs, such as meperidine (Demerol), fentanyl, propoxyphene, and methadone are not commonly tested for in most pre-employment situations, however, are being increasing included in random testing.

A confirmation test (usually GC/MS, or LC/MS/MS) can tell the difference between chemically similar drugs such as methamphetamine and methylenedioxymethamphetamine (MDMA or ecstasy).