Southern Tagalog, the Batangas Regional Hospital serves as the referral center for patients coming from lower category hospitals in the Province of Batangas, Quezon and the island provinces of Romblon, Oriental and Occidental Mindoro.

Region IV is divided into two, Region IV-A CALABARAZON to include  the provinces of Cavite, Laguna, Batangas, Rizal and Quezon. Region IV B  MIMAROPA to include Mindoro (Oriental and Occidental) Marinduque,  Romblon and Palawan.

There are four (4) Congressional Districts within the province of  Batangas. The most populous being the Second District (to which Batangas  City belongs) and the Fourth District. Batangas province has three  cities,  Batangas City (the Capital)  Lipa City and Tanauan City. In addition,  Batangas province has 31 municipalities.

The Congressional Districts outside the province but within the region are Oriental Mindoro, Occidental Mindoro, Laguna, Quezon, Cavite, Romblon and Rizal. These districts are the source of patients  of the Batangas Regional Hospital, the primary source being the province of Batangas. The island provinces of Oriental and Occidental Mindoro comes next probably because the port of Batangas is the gateway to South Luzon and the first  stop.