Drug use in the workplace is a problem, both in terms of public health and expense. Workplace drug testing programs serve as deterrents to drug use. Model programs, such as that of the Department of Transportation, use urine screening and are federally regulated or follow federal standards. An essential participant in this process is the medical review officer (MRO), a licensed physician who interprets the laboratory results generated from a workplace drug testing program. As a result of their training and experience with toxicology, collection of evidence, testimony, and recognition of the physical signs of drug abuse, medical examiners and forensic pathologists are well suited to serve as MROs. Recent regulations require the completion of training courses and MRO certification as prerequisites for participation in federal drug testing programs. Several courses are available to train physicians to participate as MROs.