I have spent the past nearly 40 years assisting not-for-profit, mission-driven organizations to improve their effectiveness, performance and long-term viability. These organizations range in size from a small community agency to a multi-billion dollar health care system. In these varied settings, I have served as consultant, middle manager, senior executive and chief executive officer. I have also participated on a number of not-for-profit boards of directors, offering me a unique, multi-faceted line of sight into how such organizations succeed – and fail. I have led a number of organizational turnarounds and transformations, and understand that the key to success is to work collaboratively with those served, staff, managers, executives, board members, funders, regulators, labor unions and all those with a vested interest in that organization. I have also experienced firsthand the most often overlooked and underappreciated aspect of the transformation process: the critical nature of organizational culture.