An emerging research agenda focuses on social media’s influence on political activism. Specific attention has recently been paid to digital social movement organizing and action repertoire development. The literature acknowledges the changing face of activism at the movement level, but little is known about the relationship between social movement organizations (SMOs) and digital action repertoires. Understanding this relationship is critical because strong adherence to values is at the heart of establishing action repertoires with legitimacy and persistence. In this paper, we rely on a two-year longitudinal study of the Swedish affiliate of Amnesty International. We examine the transformation in engagement and interaction that followed the organization’s introduction of new action repertoires. Drawing on resource mobilization theory and the collective action space model, we elaborate how new action repertoires both stabilized and challenged the values of the SMO, as well as gradually broadened the interactions of supporters and deepened their modes of engagement. We offer a value-based model on the antecedents and effects of new action repertoires from the SMO perspective. The empirical findings and the model build new theory on social media and digital activism at the organizational level, complementing the predominant movement level research in the extant literature.