Medical family and systemic psychotherapy is an evolving field in the UK. Its central aim is to support individuals living with illness, their families, and caring networks to find ways of living well enough, without allowing the health condition to dominate. This work also enhances the resilience and capacity of healthcare staff, contributing to more relationally informed care. The historical separation of physical and psychological treatment within healthcare systems has created barriers, yet contemporary practice increasingly emphasises integration, collaboration, and patient- and family-centred approaches. In this chapter, we provide a model of systemic formulation with people with physical health conditions that considers biological, psychological, relational, and cultural dimensions. Evidence from across diverse health contexts illustrates how family—and relationally inclusive, transdiagnostic approaches strengthen engagement with medical treatments, ways of coping, communication, and resilience across the lifespan. By fostering collaboration, inclusivity, and reflexivity, medical family and systemic psychotherapy offers a vital contribution to future healthcare, supporting both patients and practitioners to thrive in the face of illness. The chapter concludes with a call to action: to further develop services, research, training, and workforce capacity in medical family and systemic psychotherapy, whilst embedding systemic thinking across the NHS and beyond.