As the basic political unit, the Barangay serves as the primary planning and implementing unit of government policies, plans, programs, projects, and activities in the community, and as a forum wherein the collective views of the people may be expressed, crystallized and considered, and where disputes may be amicably settled. (Section 384, Local Government Code of 1991)
Sison is comprised of twenty eight (28) barangays wherein 5 barangays namely: Poblacion Central, Poblacion Norte, Poblacion Sur, Paldit and Labayug are considered urban barangays and the rest are all rural barangays. The municipality belongs to the 5th Congressional district. It is governed by the Local Government Code of 1991 and its officials are elected by the people and serve their constituents for a three-year tenure.