OBJECTIVE: To assess healthcare utilization and associated cost in schizophrenia and schizoaffective patients pre/post risperidone long-acting injectable (RLAI) treatment initiation. METHODS: A retrospective evaluation utilized pharmacy and medical claims to assess healthcare resource utilization and costs of adult schizophrenia patients from a mental health subset of managed care data. Inclusion criteria required a diagnosis of schizophrenia or schizoaffective disorder, at least one claim for RLAI between December 2003 and June 2004, and six months of continuous eligibility criteria pre and post the initial RLAI claim. The initial RLAI claim served as the index date. The observation period was 12 months, including 6-month pre and 6-month post RLAI treatment initiation where patients served as their own control. Healthcare utilization outcome variables included hospitalizations, emergency room use, outpatient visits, and medications. Costs represent the amount paid by the health plan for services. RESULTS: Results are available for the 26 patients meeting inclusion criteria. Mean patient age was 37 ± 13.4 years, and 53.8% of the population were male. The mean number hospitalizations per patient decreased from 0.77 in the pre-period to 0.35 in the post-period (p=0.06). The costs for hospitalizations decreased from $14,456 ± $28,745 in the pre-period to $4,201 ± $13,876 (p<0.05). Outpatient utilization remained statistically unchanged between the pre and post period, while the costs for psychoactive medications significantly increased in the post period. Total healthcare costs trended downward, from an average of $22,650 ± $30,856 in the pre-period to $15,182 ± $18,209 in the post-period (p=0.09). Sensitivity analyses conducted around the index date resulted in a statistically significant decrease in total health care costs in the post period. CONCLUSIONS: In this US managed care patient population, hospitalization costs significantly decreased post (RLAI) treatment initiation. Further studies with larger sample sizes are needed to confirm findings.