In 2011 the Rockefeller Foundation is conducting a Search on Multiple-use water Services to explore opportunities to expand MUS as a potential future investment for the Foundation to help create better health outcomes and generate income based on improved water service delivery. This exploration focuses on understanding the barriers that limit the scaling of MUS, their comparative importance, and possible approaches to overcoming challenges and supporting opportunities for scaling. This Search includes the following four initiatives. First, Winrock International and IDEO are developing MUS working models and prototypes. Second, the International Water Management Institute (IWMI) and International Water and Sanitation Center (IRC) with national partners are undertaking country studies to identify barriers and potentials for scaling MUS. The selected countries with highest potentials for scaling MUS are: India, Nepal, Ethiopia, Ghana and Tanzania. Three main scaling pathways are examined: domestic-plus, irrigation-plus, and community-based MUS approaches. A third initiative is by the John Hopkins University Global Water Program, which organized a conference in Bellagio, Italy, from August 29th to September 1st, 2011. By convening leading experts in water and related fields, this conference identified barriers and opportunities to shifting the paradigm in the water sector from a single use development context to a multiple use context. Fourth, on 13 and 14 October, the Pacific Institute, Oakland, organized a MUS Convening. Participants from 11 countries in Africa, Asia, Latin America, USA and elsewhere developed recommendations to make the MUS framework a more robust and sustainable approach, so that it: ensures equity, protects the environment, builds climate resilience, incorporates sanitation and public health, and is designed for long-term success to improve the lives of the poorest communities. Gaps in our current understanding of MUS were identified as well as ideas for a concept note on moving MUS forward in the next year. The findings of these initiatives will be presented at a meeting on 11-13 January in New York, which will allow the Foundation to decide on further steps.