Shared understanding between diverse technology stakeholders is a key driver of IT-Business alignment, also underpinning successful adaptive, IS development activities. Lack of shared understanding creates representational gaps, innovation blindness and different technology frames which create barriers to development and implementation of technology. Applying a socio-material perspective to Leonard-Barton’s model of mutual adaptation between technology and organization, as well as research on shared capabilities between IS and business stakeholders, we examine the process by which shared understanding emerges during the design, development and implementation of IT systems. We followed key multi-disciplinary stakeholder groups over a two-year period during the development and implementation of a health information system. We report on events during the project that we call ruptures – highly charged incidents which reveal a lack shared understanding between stakeholders. We argue that ruptures occur during the mutual adaptation of organizational and technological elements necessitated by the implementation process and are precipitated by the constitutive entanglement of social and technological elements. They reveal serious misalignments among stakeholders and in relation to the technology as its material properties become more concrete. We investigate the emergence of ruptures and the mechanisms by which they influence stakeholders, the implementation process and its outcomes.