Barangay Nagbunga

Barangay Nagbunga forms part of Castillejos, a municipality in Zambales, and is classified as a large barangay.

According to the 2020 Philippine census, Barangay Nagbunga had a population of 6,962. This made it the 4th largest of 14 barangays in Castillejos by population, placing it in the upper half of the municipality. Residents of Barangay Nagbunga accounted for approximately 10.25% of the total population of Castillejos, which stood at 67,889 in the same census year.

The barangay recorded 6,202 residents in the 2015 intercensal count and 6,962 residents in the 2020 Census — a net change of +12.3%, consistent with a growing settlement. Barangay Nagbunga is officially classified as urban, reflecting the density and built-up character of the area.

Castillejos is a municipality comprising 14 barangays, and serves as the governing unit directly responsible for local services in Barangay Nagbunga, including public health, sanitation, peace and order, and civil registration. Within the wider province of Zambales, which contains 247 barangays across its component cities and municipalities, Barangay Nagbunga ranks 17th by 2020 population. Zambales is classified as a 2nd by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

The barangay's legislative and executive affairs are handled by a Punong Barangay and the Sangguniang Barangay, elected nationwide during the Barangay and SK Elections. The next BSKE is scheduled for Monday, November 2, 2026, following the synchronized election schedule set by COMELEC Resolution No. 11191.