Using assessment data from the Substance Abuse Treatment Support System, we estimated the economic benefit of chemical dependency treatment to employers. A cohort of individuals (N = 498) treated at Kaiser Permanente's Addiction Medicine programs in Southern California completed assessments before and at least 30 days after treatment began. Compared to intake, subsequent assessments indicated substantial reduction in the number of patients who missed work, were late for work, were less productive than usual at work, and/or had conflict with coworkers or management. The net economic value of these improvements to their employers depended upon the utilization rate of the benefit and the salary level of the employees receiving treatment. For a utilization rate of 0.9% and a mean annual salary of US$45,000, the net benefit of treatment was US$1,538 for > or = 61 days of treatment. Based solely upon these employment-related measures, without factoring in the medical cost offset or indirect benefits of treatment that may help employees to maintain higher levels of productivity, employers break even on an investment of US$30 per member per year for a chemical dependency treatment benefit if the mean annual salary of the employees participating in treatment is US$36,565.