This paper examines an organization’s adoption of a standard based innovation management system (IMS) to systematize and lead its innovation efforts. The organization, a large public hospital, characterized as an early implementor of the standard based IMS approach to innovation management, was analyzed during a fouryear time span via a longitudinal study. The paper utilizes components of neo institutional theory as a lens to explain the empirical findings, adopting a legitimacy-as-a-process perspective to trace how the IMS system became a legitimate approach to innovation management, through institutional work. By analyzing the organization from its initial planning to its implementation of the system, the paper presents an order of legitimizing an innovation management system.