Background <p>As the number and complexity of patients living with serious illness continue to rise, delivering care that is both effective and responsive to individual life contexts has become increasingly important. Despite its potential benefits, the implementation of contextualized care in the management of serious illness remains limited and poorly understood. To address this gap, this study aimed to identify barriers and facilitators influencing the delivery of contextualized care for patients with serious illness, as perceived by healthcare professionals (HCPs), and to generate recommendations for improving its implementation.</p> Methods <p>Three focus groups were conducted with 20 HCPs from multiple disciplines and hospital settings in the Netherlands, all involved in the care of patients with serious illness. Discussions were guided and analysed using a directed content analysis informed by the COM-B model (Capability, Opportunity, Motivation–Behaviour) combined with the Theoretical Domains Framework. Factors were mapped to intervention functions from the Behaviour Change Wheel (BCW) to provide recommendations.</p> Results <p>Nine factors influencing contextualized care were identified across COM-B components. Capability-related factors included skills and knowledge to engage with the relevant patient context and the ability to distinguish between general and clinically relevant context. Opportunity-related factors included environmental conditions, fragmented information systems, systemic incentives misaligned with contextual care, a lack of shared team norms, collaboration challenges, and the perceived emotional complexity of contextual conversations in the palliative phase. Motivation-related factors included strong intrinsic commitment to person-centred care and awareness of the consequences of overlooking context for patients, HCPs, and the overall system. Most barriers were concentrated in the <i>Opportunity</i> component, with environmental and team-level constraints often outweighing individual motivation and basic skills.</p> Conclusions <p>Delivering contextualized care for patients with serious illness is not primarily limited by individual willingness or basic capability but by environmental and systemic feasibility. Sustainable implementation requires multilevel strategies targeting team culture, interprofessional collaboration, and a supportive infrastructure. Moving from individual intent to shared norms may improve both patient outcomes and resource efficiency. Key steps include continuous education, embedding contextual care in team culture, adapting workflows and documentation, and integrating contextualization into quality measures and incentives.</p>