This article examines costs as they relate to the financial costs of providing drug abuse treatment in private and public health plans, costs to society relating to drug abuse, and many smaller costing studies of various stakeholders in the health care system. A bibliography is developed from searches across PubMed, Web of Science, and other bibliographic sources. The review indicates that a wide collection of cost findings is available to policy makers. For example, the financial aspects of health plans have been dominated by considerations of actuarial costs of parity for drug abuse treatment. Cost-of-illness methods have been developed and extended to drug abuse costing to measure the national level of burden and are important to the economic evaluation of interventions at the program level. Costing is done in many small and focused studies, reflecting the interests of different stakeholders in the health care system. For costs in programs and health plans, as well as cost offsets of the impact of substance abuse treatment on medical expenditures, findings are surprisingly important to policy makers. Maintaining ongoing research that is highly policy relevant from the point of view of health services, more is needed on costing concepts and measurement applications.