Shared decision-making is commonly described as a collaborative clinical ideal, yet collaboration does not by itself determine who owns the responsibilities generated by a decision. In interprofessional care, patients, physicians, nurses, consultants, family members, and institutions may contribute different forms of knowledge, influence, authority, implementation work, and retrospective answerability. This philosophical analysis examines that unresolved ownership problem by treating the clinical decision episode, rather than a single moment of consent, as the relevant unit of analysis. It distinguishes epistemic, communicative, procedural, and moral contributions from implementation responsibility and retrospective accountability, and argues that these dimensions can overlap without becoming interchangeable. The analysis further proposes that responsibility may be distributed across persons, professions, institutions, and phases of care without being diluted into collective nonresponsibility. On this basis, the article develops a proposed Decision-Ownership Framework for identifying who knew, communicated, authorized, influenced, acted, and remains answerable within a shared decision. The framework is intended as a conceptual and normative aid rather than a validated clinical tool, legal allocation rule, or quantitative method for apportioning blame. Its usefulness is therefore bounded by differences in capacity, professional authority, institutional structure, jurisdiction, clinical urgency, epistemic power, and the changing configuration of responsibility across time. The central claim is that a shared decision can be genuinely co-produced while still generating differentiated and sometimes overlapping obligations. Accordingly, ownership should be reconstructed as a pattern of responsibility relations rather than a single transferable status attached to one decision-maker.
