This report was developed for The Office of National Drug Control Policy (ONDCP) which asked The Lewin Group to calculate more current estimates of the societal cost of drug abuse. In the context of this report, the phrase "drug abuse" is used to refer to consequences of using illicit drugs, as well as societal costs pertaining to the enforcement of drug laws. This study does not address costs related to abuse of or dependence on legal substances that may be termed drugs such as alcohol, tobacco, or prescription medications. The most recent previous estimates of drug abuse related costs are for 1995 as developed by Harwood et al. (1998). In addition to providing new estimates of the societal cost of drug abuse, this report provides annual estimates for 1992 through 1998 and projections for 1999 and 2000 that are consistently developed, so that trends in the overall societal cost and in component costs of drug abuse can be evaluated. Projections are only provided for 1999 and 2000, because there is a significant lag in the availability of the base data for estimating the component values. For the majority of components, the most recent data available is from 1998. The estimates have followed guidelines developed by the U.S. Public Health Service for cost-of illness studies. These guidelines have been applied in earlier studies of drug abuse in the U.S. (e.g., for 1992, 1985, 1980, and 1977), and to cost-of-illness studies for virtually all of the major medical problems. Accordingly, these estimates can be compared meaningfully to estimates for diseases, such as cancer, stroke, heart disease, diabetes, alcohol abuse and mental illness. The results of this study are summarized in five sections. The first section presents the overall estimates of the cost of drug abuse for 1992 through 1998 and projections for 1999 and 2000. Then, sections two through four demonstrate how the costs in each of the three major cost categories changed between 1992 and 2000. All of the three major cost categories contain costs related to crime. The fifth section below extracts the crime-related costs from each of the other major cost categories and summarizes them. Finally, the sixth section below provides a brief discussion of the study's results.