Under a long-term agreement with UNAIDS, EHG was commissioned to undertake an evidence review designed as an exploratory piece of retrospective work, looking back at the extent to which the UNAIDS Secretariat and Co-Sponsors at country level contributed to RSSH (e.g. being instrumental, having catalytic role, missed some opportunities) and what systems should have been in place to better deal with COVID-19 and other potential challenges in the future. The work captured examples of where the Joint Programme at the country level (including joint planning, monitoring and review) has been at the right place, at the right time and triggered the right processes or change. The team conducted four targeted country case studies (Dominican Republic, Ethiopia, Ghana and Kyrgyzstan) focusing on six critical elements with an eye on integrating further HIV services which proved less robust than anticipated in lieu of the current pandemic. The review was grounded in a realist approach looking at “What works, for whom, in what respects, to what extent, in what contexts, and how?” where the team looked at the mechanism that explain the “how” results/outcomes/lessons learnt were caused and the influence of the context.