It has been more than 20 years since Brazil's 1988 Constitution formally established the Unified Health System (Sistema Unico de Saude, SUS). Building on reforms that started in the 1980s, the SUS represented a significant break with the past, establishing health care as a fundamental right and duty of the state and initiating a process of fundamentally transforming Brazil's health system to achieve this goal. This report aims to answer two main questions. First is have the SUS reforms transformed the health system as envisaged 20 years ago? Second, have the reforms led to improvements with regard to access to services, financial protection, and health outcomes? In addressing these questions, the report revisits ground covered in previous assessments, but also brings to bear additional or more recent data and places Brazil's health system in an international context. The report shows that the health system reforms can be credited with significant achievements. The report points to some promising directions for health system reforms that will allow Brazil to continue building on the achievements made to date. Although it is possible to reach some broad conclusions, there are many gaps and caveats in the story. A secondary aim of the report is to consider how some of these gaps can be filled through improved monitoring of health system performance and future research. The introduction presents a short review of the history of the SUS, describes the core principles that underpinned the reform, and offers a brief description of the evaluation framework used in the report. Chapter two presents findings on the extent to which the SUS reforms have transformed the health system, focusing on delivery, financing, and governance. Chapter three asks whether the reforms have resulted in improved outcomes with regard to access to services, financial protection, quality, health outcomes, and efficiency. The concluding chapter presents the main findings of the study, discusses some policy directions for addressing the current shortcomings, and identifies areas for further research.