Although the existing technology for drug testing can detect the presence, absence, identity, and concentration of target analytes, all procedures and methods for drug analysis are subject to error, notably random errors. The interpretation of drug-test results is less advanced than the analytical procedures, and urinalysis does not yield information on past or present patterns of drug use, abuse, or drug dependence; drug-related mental or physical impairment; or other effects at a given time. A comprehensive and universal nationwide system of regulating nonmedical drug-use testing should be established, preferably in the form of Federal licensure with provisions for alternative accreditation under standards identical to those for Federal licensure. Other recommendations pertain to standards and procedures for drug testing. 223 footnotes.