Older adults with multiple chronic conditions (multimorbidity) face complex self-management routines, including symptom monitoring, managing multiple medications, coordinating healthcare visits, communicating with multiple healthcare providers and processing and managing potentially conflicting advice on conditions. While much research exists on single disease management, little, if any research has explored the topic of technology to support those with multimorbidity, particularly older adults, to self-manage with support from a care network. This paper describes a large qualitative study with 125 participants, including older adults with multimorbidity and those who care for them, across two European countries. Key findings related to the: impact of multimorbidity, complexities involved in self-management, motivators and barriers to self-management, sources of support and poor communication as a barrier to care coordination. We present important concepts and design features for a digital health system that aim to address requirements derived from this study. CCS CONCEPTS • Human Centred Computing → Human Computer Interaction; Empirical Studies in HCI.