Puerto Rico Municipio Map: All 78 Municipios

Under the Spanish colonial administrative system that governed the island for four centuries prior to 1898, settlements were established around a central Catholic parish plaza (plaza pública) and designated as municipal partidos. The 1952 Constitution of the Commonwealth of Puerto Rico formalized these boundaries.

To decentralize public administration from the central government in San Juan, the Legislative Assembly enacted the Autonomous Municipalities Act (Ley de Municipios Autónomos, Ley 81 de 1991, codified in the Municipal Code of 2020). This law established a hierarchical transfer of powers, enabling qualifying municipios to take direct control over local land use planning, permit issuance, property tax collection, and waste management.

Because municipios handle both local zoning and regional public works, the U.S. Census Bureau classifies all 78 municipios as primary county equivalents (FIPS Code 72), identical in statistical standing to mainland counties.

The rugged Cordillera Central mountain range bisects the island from east to west. Interior mountain municipios like Utuado, Jayuya, Adjuntas, and Orocovis feature steep coffee plantations, tropical rainforests, and Puerto Rico's highest peak, Cerro de Punta (4,390 ft). These municipalities maintain specialized rural civil defense squads for hurricane landslides.

The northern coastal plain houses the dense San Juan Metropolitan Area (San Juan, Bayamón, Carolina, Guaynabo, Cataño), where over 1.2 million residents reside within an integrated highway and Tren Urbano transit corridor.

To the east lie Puerto Rico's two offshore island municipalities: Vieques and Culebra. Known as the Spanish Virgin Islands, these island municipios rely on maritime ferry links to Ceiba and feature pristine bioluminescent bays and wildlife refuges on former U.S. Navy lands.