Mountain agricultural systems (MASs) are multifunctional and multidimensional sociocultural systems. They are constantly influenced by many factors whose intensity and impacts are unpredictable. The recent Hindu Kush–Himalayan Assessment Report highlighted the need to integrate mountain perspectives into governance decisions on sustaining resources in the Hindu Kush–Himalayan region, emphasizing the importance of sustainable MASs. Our reflective literature review identified 3 barriers to advancing the agenda for sustainable MASs: (1) the disconnect of normative orientations for sustainability at differen scales, (2) inadequate alignment between stakeholders' sustainability orientation and scientific evidence, and (3) weak integration of scientific evidence into the formulation of mountain specific solutions for sustainability. To address these barriers, we propose a conceptual, regional (mountain specific), transdisciplinary framework with an interscale science–policy interface. This will help scientific evidence to be incorporated in future policies and programs on sustainable MASs while being responsive to the needs of mountain farming communities and stakeholders who benefit from broader services. The framework emphasizes the connection between normative orientations for sustainability, science evidence, and solutions for sustainability through the use of iterative transdisciplinary knowledge-generation and knowledge-integration multiscale feedback processes. Thus, the key to advancing the agenda for sustainability of MASs lies in aligning scientific evidence with existing normative orientations for sustainability at local, subnational, national, regional, and global levels. The alignment triggers sustainability-oriented solutions. This should highlight MASs globally, increasing investment while acknowledging MAS specificities and niche opportunities. In turn, this will strengthen national policies and programs specific to MASs and facilitate integrated farm management through interdisciplinary extension and delivery services.