People with complex health and social needs cannot reliably get the care and support that they need – a problem that resonates with any funder concerned with health care or social services delivery, health equity, social justice, or vulnerable populations. The field of complex care seeks to create, expand, support, and improve models and innovative approaches to care that can better serve these hard-to-reach individuals. This report summarizes key issues relevant to understanding complex care and offers resources and case studies for funders interested in entering the field or deepening their existing work. In the hope of engaging more funders and inspiring increased investment in this space, it profiles funding opportunities, explores existing models, and shares philanthropic lessons learned. By presenting a range of approaches, large and small, the report can assist funders of all types and sizes to view their work through the lens of complex care.