The municipalities of Puerto Rico are the second-order administrative divisions in the Commonwealth of Puerto Rico. There are 78 such administrative divisions covering all 78 incorporated towns and cities. Each municipality is led by a mayor and divided into barrios, though the latter are not vested with any political authority. Every municipality is governed by the Autonomous Municipalities Act of 1991, which establishes that every municipality must have an elected strong mayor with a municipal legislature as the form of government. Each legislature must be unicameral, with the number of members related to adequate representation of the total municipality's population. In contrast to other jurisdictions, both the mayors and the municipal legislators are elected on the same date and for th