Abstract / Summary Botswana has been a leader in galvanizing an effective regional and global response to the epidemic. Despite being one of the countries hardest hit by HIV/AIDS, Botswana was one of the first countries in Africa to provide free universal public antiretroviral therapy (ART) for eligible citizens. Through proactive policies and programs around HIV/AIDS, Botswana has made major gains and has laid the foundation for continued progress against the epidemic. Evaluation of strategic information is necessary to inform the construction, implementation, scale up, and improvement of sustainable programs upon that foundation, while making the best i use of a set of constrained resources. As the national response matures, new priorities have emerged for Botswana's National ART Program, known as Masa, the Setswana word for new dawn. These priorities include improving patient outcomes and ensuring the long-term financial sustainability of the program, while maintaining adequate health system performance and patient satisfaction. The proposed study directly addresses these priorities through a comprehensive, mixed methods, and sub-national evaluation which makes use of a rich, longitudinal national registry of Masa patient data, in combination with additional survey data. The proposed study will be conducted by a consortium between the University of Botswana School of Medicine (UB SOM), the Harvard School of Public Health (HSPH) and the Botswana Ministry of Health (MOH). i Sanders D, Haines A. (2006). Implementation research is needed to achieve international health goals. PLoS Med, 3(6): e186.