This article examines ineffective efforts to address the Technology Assessment deficit in Europe and asks how TA approaches can spread across diverse socio-political contexts while considering the specificities of receiving environments. Based on participatory observations and in-depth empirical case studies, we draw on Sheila Jasanoff’s work and identify a discursive shift from an institutional deficit to a knowledge deficit of TA, co-produced with an asymmetrical form of cosmopolitan epistemic subsidiarity. Our analysis highlights the epistemic supremacy of existing TA institutions, a situation in which newcomers fully consent to become reliant on foreign imports of TA practices and knowledge. We argue to carefully disentangle the normative dimensions and power inequalities of the standardization of TA approaches, as this can threaten the diversity of perspectives of the knowledge produced and, consequently, the effectiveness and legitimacy of public decision-making. We conclude by identifying research avenues into epistemic subsidiarity for TA practice and scholarship.