[A matter of the system: how shared decision making is self-scaling across the healthcare system].

Shared decision making (SDM) is still scarcely implemented in Germany-a statement that could have served as an appropriate opening line of literally any article on SDM during the last decades. But why? Today, SDM is regarded as the gold standard for reaching decisions about the most suitable treatment, a view reinforced by the German Patients' Rights Act. How can it be that SDM nonetheless has not gained noticeable traction in medical practice?Drawing on the framework of synergetics, this article outlines which factors within the German healthcare system are responsible for this stagnation and how those same factors can be utilized to foster the emergence of SDM. As empirical evidence for this analysis, the Kiel Model demonstrates how SDM was implemented hospital-wide through the SHARE TO CARE program and was operationalized as a reimbursable service covered by health insurance. Its positive effects on quality of care and cost-effectiveness enabled a self-sustaining and thus sustainable SDM infrastructure.Finally, the article describes which simple regulatory adjustments by legislation would allow SDM to scale across hospitals nationwide through self-organization following the Kiel Model.