This paper aims to analyze assumptions about the central concept of "centering" patients and families in patient- and family-centered care (PFCC) research. It uses a structured problematization method to identify three main areas of assumptions in PFCC intervention research: 1) spatial assumptions that patients and families can be centered through proximity, 2) assumptions that care can be democratized by including patients and families, and 3) assumptions that centering is primarily a problem and accomplishment for nursing. The paper argues for adopting theoretical lenses that de-center individual actors to better account for complex relationships among multiple human and non-human actors in care practices.