Healthcare systems are under intense pressure to innovate. Using the German healthcare system as an example—with its complex structure of actors, institutions, and regulatory bodies—this chapter explores how innovations are implemented in highly complex healthcare environments. Health services research examines this complexity and addresses how innovations can be introduced and sustained within systems shaped by diverse and sometimes conflicting interests. Building on national and international findings, we provide insights into the unique structural features of the German healthcare system as a context for innovation. The specific criteria that innovations in healthcare must meet, the determinants of the implementation of innovations, and the complex conditions necessary for successful adoption in healthcare will be discussed. Furthermore, the chapter highlights the role of approaches that link science, practice, and policy, and reflects on regulatory frameworks such as the Innovation Fund. Finally, we examine how the success of innovations can be measured, emphasizing the need for comprehensive evaluation beyond effectiveness studies to capture the complexity of healthcare improvements.