UNAIDS and the Global Fund have established a continuous working relationship since 2002. The Cooperation Agreement signed in 2014 replaced the previous MoUs and strengthened the cooperation framework between the Parties, especially in terms of coordination mechanisms, communication, sharing of information, and mutual accountability. The Cooperation Agreement was “guided by the launch of the NFM” (New Funding Model), an investment approach developed by the Global Fund Strategy 2012-2016 which replaced the previous system with a more proactive, flexible and predictable funding approach intended to maximise the impact of resources invested more strategically and better aligned with stakeholders’ priorities at the country level. The overall purpose of the evaluation is to provide learning on what works and what does not (and why), as well as actionable recommendations to improve the functioning of the partnership at the global, regional and country levels in order to optimise resources and maximise impact. One of the objectives of this evaluation is to provide a comprehensive, objective, rigorous, evidence-based assessment of the collaboration developed under the Cooperation Agreement. In so doing, the evaluation will look at both the internal and external aspects of the partnership with a special focus on the cooperation areas and the organisational factors that may further strengthen the relevance, effectiveness, efficiency and sustainability of the partnership and the NFM in particular. The evaluation team will use a range of mixed-methodologies to collect and analyse data, including the review of the relevant literature and documentation; the use of both quantitative and qualitative metrics to assess and compare the different components of the partnership across countries and stakeholders; the conduct of stakeholders interviews and online survey; the assessment of thematic case studies through field missions to six countries in two regions (Eastern and Southern Africa, and Asia Pacific). All these methods will take into account the “assessment of key organizational and contextual factors to sustain effective partnerships” which can therefore be understood as a cross-cutting issue on the health and success of the partnership.