This chapter examines the social inclusion outcomes of a rural WASH (water, sanitation, and hygiene) intervention in Cambodia (the Cambodia Project) using the Capability Approach and its three determinants of capability change: effective access to resources, effective agency, and socio-structural context. Drawing on mixed-methods data from mid-term and end-of-term evaluations across nine provinces, the chapter analyses how poor and vulnerable households—particularly women, elderly people, and persons with disabilities—converted improved access to water and sanitation into substantive well-being outcomes. While the Cambodia Project significantly expanded formal access to WASH services, capability gains were uneven. Affordability constraints, rigid subsidy design, and limited adaptability of sanitation technologies restricted households’ ability to act on available resources, often forcing trade-offs between basic subsistence and WASH investments. Socio-structural factors further shaped outcomes: uneven participation in awareness-raising activities, constrained intra-household decision-making, politicised poverty targeting through the ID Poor system, and limited involvement of people with disabilities in service design all mediated conversion processes. The findings demonstrate that service reach alone is insufficient for social inclusion and underscore the value of a capability-based framework for assessing equitable and sustainable WASH outcomes.