While increased collaboration is often promoted as a solution for fragmented care, it does not automatically result in person-centred or seamless care—particularly for older adults with complex needs. This presentation draws on findings from a doctoral project that explored how inter-organisational collaboration and adaptability shape care coordination in the borderlands between healthcare and social care in Sweden. Across four qualitative and systems-oriented studies—including ethnographic fieldwork, interviews, and document analysis—the thesis examined discharge processes, care transitions, and adaptive strategies across hospitals, primary care, municipal services, and ambulance care. Findings reveal that collaboration, in itself, is not sufficient. Instead, person-centred coordination depends on the presence of relational continuity, functioning communication pathways, shared accountability, and contextual responsiveness. Effective collaboration occurs when professionals not only cooperate, but also take responsibility and respond to the specific needs of patients—ensuring the right care is delivered by the right actor at the right time. Moreover, system structures and policies often constrain these efforts. Front-line staff are frequently left to bridge organisational gaps through informal practices, workarounds, and trust-based relationships. These relational and adaptive practices are central to delivering truly person-centred care—but are often overlooked in governance and system design. This presentation challenges the assumption that “more collaboration” is inherently better. Instead, it calls for attention to how collaboration is enacted, and whether it enables professionals to act accountably and responsively toward patients. It argues that person-centred care across boundaries requires more than integration—it requires shared purpose, mutual trust, and the organisational space to act. This session will be relevant for researchers, practitioners, and policymakers seeking to understand and support the conditions that truly enable person-centred, cross-boundary care.