Collaboration between nephrology consultants and intensive care unit (ICU) teams is important in light of the high incidence of acute kidney injury in today's ICUs. Although there is considerable debate about how nephrology consultants and ICU teams should collaborate, communicative dynamics between the 2 parties remain poorly understood. This article describes interactions between nephrology consultants and ICU teams in the academic medical setting.Focused ethnography using semi-structured interviews and participant observation.Purposive sampling was used to enroll nephrologists, nephrology fellows, and ICU practitioners across several roles collaborating in 3 ICUs (a medical ICU, a surgical ICU, and a cardiothoracic surgical ICU) of a large urban US academic medical center. Participant observation (150 hours) and semi-structured interviews (35) continued until theoretical saturation.Interview and fieldnote transcripts were coded in an iterative team-based process. Explanation was developed using an abductive approach.Nephrology consultants and surgical ICU teams exhibited discordant preferences about the aggressiveness of renal replacement therapy based on different understandings of physiology, goals of care, and acuity. Collaborative difficulties resulting from this discordance led to nephrology consultants often serving as dialysis proceduralists rather than diagnosticians in surgical ICUs and to consultants sometimes choosing not to express disagreements about clinical care because of the belief that doing so would not lead to changes in the course of care.Aspects of this single-site study of an academic medical center may not be generalizable to other clinical settings and samples. Surgical team perspectives would provide further detail about nephrology consultation in surgical ICUs. The effects of findings on patient care were not examined.Differences in approach between internal medicine-trained nephrologists and anesthesia- and surgery-trained intensivists and surgeons led to collaborative difficulties in surgical ICUs. These findings stress the need for medical teamwork research and intervention to address issues stemming from disciplinary siloing rooted in long-term socialization to different disciplinary practices.