The authors analyze the pilot implementation of a statewide automated outcome monitoring system (OMS) in California, using the perspectives of substance abuse treatment providers responsible for its day-to-day operation. To gain a better understanding of changes experienced by staff and their perceptions of barriers and facilitators of implementation, they conducted 28 focus groups designed to inform midstream adjustments to the system prior to its possible roll-out. Qualitative analysis of the focus group data revealed five important factors influencing implementation: the treatment provider's ethos, the time-consuming nature of the OMS, staff buy-in, resources, and counselor and program discretion. Lessons learned underscored the importance of taking into consideration aspects of organizational change and institutional resources and infrastructure when implementing a major change such as an automated OMS. Findings might be useful to those designing and implementing similar systems or other large organizational change initiatives.