Making mistakes during organizational change is surprisingly easy despite extensive “lesson learning” in the professional change management literature. Human services leaders overseeing organizational changes such as integrating a new model or evidence-based practice must prepare to monitor and adjust their course. The “learning while doing” approach relies on data and on adjusting the implementation plan and the underlying ways of doing business. This article describes one agency's successful large-scale administrative, program, and practice change that resulted in better outcomes, stronger infrastructure as a learning organization, and a set of lessons with implications for change management in child welfare and other human services organizations.