Gen. Mariano Alvarez was originally divided into 10 barangays (more appropriately, areas) that were parts of the Carmona Resettlement Project. It comprised the resettlement areas in Barangays San Jose, and San Gabriel, and a portion of Cabilang Baybay, a barangay of the municipality of Carmona. San Jose consists of Areas A and B, while San Gabriel is composed of Areas C, D, E, F, G, H, I, J, and K.On March 25, 1985, by virtue of legislative and administrative acts, a referendum was made to redivide the municipality into the current 27 barangays. They were named after the revolutionary leaders of the province of Cavite - including those related to the great general to whom the municipality was named after - and the barangay captains and other prominent personalities who led the former 10 barangays. The first appointed officials of the barangays were sworn into office en masse on June 27, 1985. Five of the current barangays are classified as poblacion barangays, or those that are within the municipality's central area. The 22 others are ordinary barangays.