Improvement of public services and raising the citizens' quality of life is one of the biggest concerns of public sector. Changing the way public organizations operate could support such an improvement. In this regard, business model framework is an emerging field of research that could shed some new light. Yet, in case of public organizations, business model innovation remains heavily underexplored. The purpose of this chapter is threefold, to indicate and discuss the opportunities of adapting the business model innovation theory to public organizations, to conceptualize its theoretical framework, and to explore the role of public service design in the process of innovating public sector business models.