Legislative districts of Bulacan

The component city of San Jose del Monte, while remaining an integral part of the province, was granted separate congressional representation in 2003.

Valenzuela, then a municipality, was separated from Bulacan to form the Metropolitan Manila Area on November 7, 1975, by virtue of Presidential Decree No.

The province was reapportioned into four congressional districts under the new Constitution[3] which was proclaimed on February 11, 1987, and elected members to the restored House of Representatives starting that same year.

Like in the case of San Jose del Monte, the residents of Malolos would have remained as part of the province's 1st Sangguniang Panlalawigan district.

However, on January 25, 2010, the Supreme Court declared the creation of the Legislative District of Malolos as unconstitutional, citing that the city's population at the time did not meet the minimum 250,000 count required by the constitution.