Since 2020, the municipalities are organized under the Municipal Code of Puerto Rico (Law. No. 107 of 2020). Each legislature must be
unicameral, with the number of members related to adequate representation of the total population of the municipality. In contrast to other jurisdictions, both the mayors and the municipal legislators are elected on the same date and for the same term of four years in office. From a political and
ekistic perspective, several differences and similarities exist between municipalities of differing population sizes. For instance, municipalities with 50,000 inhabitants or more are considered
incorporated cities, while those with fewer than 50,000 are considered
incorporated towns. Size affects the autonomy exercised by the jurisdiction: cities provide and manage their own services, while towns typically depend on nearby cities for certain services. Demographically, municipalities in Puerto Rico are equivalent to
counties in the United States, and Puerto Rican municipalities are registered as county subdivisions in the
United States census. Statistically, the municipality with the largest number of inhabitants is
San Juan, with 342,259, while
Culebra is the smallest, with around 1,792.
Arecibo is the largest in terms of geography, with around 125 mi2, and
Cataño the smallest, with around 4.8 mi2. Except for
San Juan,
Ponce,
Florida, and
Vieques, all municipalities have a
barrio equivalent to a
downtown area in the U.S. called
pueblo, officially known as
barrio-pueblo (literally "ward-town"), which typically is the site of the historic Spanish colonial settlement, administrative center, and urban core of the municipality. However, municipalities with large populations, like
Ponce, may have an urban core that consist of several barrios. In
Recent Civic Architecture in Porto Rico by Adrian C. Finlayson, architect for the Insular Department of the Interior Architecture, writing for the publication
Architectural Record in 1920, the Puerto Rican municipality is accurately described as: ==Finances==