<p>Community-dwelling, non-familial intergenerational programmes (IPs) have emerged as a promising approach to preventing social isolation and loneliness among older adults. However, there is a need for a comprehensive understanding of the key components, underlying mechanisms, and contextual factors involved in implementing such programmes. This study aimed to develop a comprehensive logic model framework for non-familial IPs to guide future programme design and implementation. A qualitative approach was employed to analyse the ‘Post für Dich!’ [Mail for You] programme in rural Lower Austria through semi-structured interviews with older adults, implementation agents, and community leaders, along with a focus group of primary school children, and a document analysis. The resulting logic model framework identifies critical inputs (e.g., local coordinator, engaged implementation agents, meeting spaces, programme flexibility), highlights the role of existing organisational settings in facilitating access to target groups, and outlines key activities (programme initiation, coordination, letter exchanges, and intergenerational events). It reports multifaceted benefits for participants, such as improved attitudes, dispelled age stereotypes, expanded social networks, and an enriched daily life for older adults. Potential community-level impacts, such as fostering multigenerational awareness and integration, are noted. This empirically grounded framework serves as a practical tool for systematically designing, implementing, and evaluating IPs across diverse settings. It can facilitate knowledge transfer, evidence-informed practice, and capacity-building efforts, contributing to the effective implementation of these interventions.</p>