This study elucidates the organizational ripple effect of a large-scale technology-based healthcare enterprise development. It addresses the interplay between organizational information technology (IT) architecture and IT governance and the mediating role of inter-organizational interdependencies and coordination mechanisms. The research questions are; what ripple effect does IT architecture create in healthcare organizations, and how? What mechanisms are being used to manage them? We take a coordination perspective to conceptualize formal and informal mechanisms for implement-ing the IT architecture integration mandate, and propose an analytical framework to develop our ar-gument. Our empirical evidence is a large networked healthcare organization engaged in an IT mega-program aimed at improving clinical services through integration and standardization facilitated by an enterprise architecture practice. Based on our findings and building on coordination theory, we contribute to the enterprise architec-ture literature by providing analysis of coordination and governance challenges in enterprise archi-tecture work. The findings demonstrate that IT architecture integration and standardization in com-plex organizational settings augment organizational coordination efforts by increasing socio-technical interdependencies which necessitate coordination-oriented hybrid governance mechanisms. Large and complex organizations involved in IT-based organizational transformation need to consider: i) socio-technical interdependencies and the ensuing coordination ripple effect of their IT architecture choices and ii) address mechanisms for lateral coordination as part of their enterprise architecture and IT governance processes if socio-technical interdependencies are to be managed adequately.