This dissertation uses existing data to help understand the effect of changes in the private insurance marketplace on SA treatment services. The author examined the impact of cost-sharing and different approaches to behavioral health benefit management on SA treatment service utilization using two separate administrative data sets and conducted analyses of the effects of cost-sharing across different types of SA treatment services. He found low rates of documented SA treatment (0.37%) but higher rates of treatment following detoxification (78%) than documented in other populations. Results demonstrate that different approaches to managing SA benefits and different levels of patient cost-sharing both significantly affect the type and amount of SA treatment utilization. Patients whose SA treatment was managed separately rather than by an HMO had less inpatient and routine outpatient treatment, but higher levels of intermediate SA treatment. Individuals with higher SA copayments were less likely than those with little or no copayment to receive residential SA treatment and specialty SA outpatient treatment; higher levels of copayments were also associated with less treatment following inpatient detoxification. More generous SA benefits are a potential approach to improving access to and quality of SA treatment, but the low rates of treatment suggest that the impact of this approach may be limited.