The papers in these proceedings were selected from those presented at a May 2003 research colloquium on the workers’ compensation medical benefit delivery system and workers’ return to work after treatment. The colloquium was held at a time when California’s workers’ compensation program was at the center of intense debate and legislative activity: While coverage and expenditures for eligible workers had increased, California’s injured workers were expressing greater dissatisfaction with the quality of their care. The colloquium brought together national experts and California stakeholders with an interest in workers’ compensation medical benefits and ways in which initiatives in other health programs might be used to improve the delivery of high-quality services to injured workers. The colloquium was intended to foster dialogue, to further research, and to spur reform of the California workers’ compensation medical benefit delivery system. The papers in these proceedings provide an overview of the access, cost, and quality issues confronting the workers’ compensation medical benefits delivery system and identify mechanisms that might be used to improve the quality and efficiency of the medical care provided to injured workers.