Microsystems are the building blocks of the healthcare system. They are the small functional frontline units that provide most healthcare to most people, be it a clinic or a ward. The microsystem improvement approach engages teams at the frontline of care with patients and families in a structured process to improve the quality of care and outcomes. This Element offers an overview of the theory of the microsystems, mesosystems, and team coaching improvement approaches, using case studies to demonstrate how the approaches have been used in practice. A critique of the emerging evidence base and the strengths and limitations of the approach is given. This title is also available as open access on Cambridge Core.