There is a shifting in development approach from community empowerment to citizen engagement. Understanding citizen engagement requires understanding of basic elements of social life that consists of structure, process and culture within the realm of community's living environment. This paper aims to elaborate elements that form and influence citizen engagement in delivering and sustaining water supply in rural Indonesia. Sustainability is explored through the lifecycle of rural water supply service delivery, from strategic plan, financing and budget allocation, construction/expansion, operational and maintenance and support system for sustaining services. A case study was conducted in four Pamsimas villages in two provinces with comparable natural environment and water system, yet contrast sustainability performance. Pamsimas is the biggest rural water supply program in Indonesia. Through in-depth interview and focus group discussion, the study found that proper citizen and government engagement since strategic plan throughout the rest of sub-cycles is key to sustainable service delivery. In four villages, sustainability is more influenced by structure elements such as government policy, program's governance and source of water than social and culture elements. Lessons from this study shall guide sector's stakeholders to better define engagement of citizen and government, particularly village government to sustain the services.