In the Philippines, an Ancestral Domain Sustainable Development and Protection Plans (ADSDPP) is a fundamental expression of ownership rights of the Indigenous Cultural Communities/Indigenous Peoples (ICCs/IPs) over their ancestral domain. The National Commission on Indigenous Peoples (NCIP) is the primary government agency responsible for the effective development planning process for all ICCs?IPs. This study inquires how an ADSDPP could be sustainable as a protection plan when a CADT on which it is anchored on is infirm. Semi-structured individual interviews and Focus Group Discussions (FGDs) were conducted to elicit the history of ancestral domain claim, and to gather information on the experiences, observations and comments of community members. A number of official documents from the Office of the Executive Secretary (OES,NCIP,DENR among others, were obtained. The data collected contributed in identifying policy influences that helped shape the nature and character of NCIP and how this has affected the implementation of the Indigenous Peoples' Rights Act in terms of ancestral domain titling and formulation of the ADSDPPs.The study applied Rajesh Tandon's concept where he stated that realities on the ground do not necessarily match with the categorization that government represents the primacy of being the ""first"" sector, the corporations or business as the ""second'' sector and civil society as the "third" sector. The ""first'' sector purpose to determine the manner in which families, institutions, associations and communities are to be managed. This study ascertained that indigenous peoples possess the readiness and are astute when engaging government and civil society pertaining to laws on indigenous peoples' rights to ancestral land domain. This readiness to meet situations is shaped by and, the outcome of Indigenous Peoples' history of land dispossession and marginalization.