This paper reports on a qualitative field study of 16 hospitals implementing an innovative technology for cardiac surgery. We examine how new routines are developed in organizations in which existing routines are reinforced by the technological and organizational context. All hospitals studied had top-tier cardiac surgery departments with excellent reputations and patient outcomes yet exhibited striking differences in the extent to which they were able to implement a new technology that required substantial changes in the operating-room-team work routine. Successful implementers underwent