Pursuant to Executive Order Number 103 dated May 17, 2002, Region IV was divided into Region 4A or CALABARZON and Region 4B or MIMAROPA. MIMAROPA stands for MI – Mindoro Occidental and Oriental, MA– Marinduque, RO – Romblon and PA – Palawan. Consistent with the mandates of Executive Order No. 103, the PNP General Order Number DPL 02-10 dated August 18, 2002 was issued which calls for the deactivation of Police Regional Office 4 and the activation of Police Regional Office 4A or CALABARZON and the Police Regional Office 4B or MIMAROPA. The two (2) new Police Regional Offices were activated on September 1, 2002 and since then, continued to perform well towards the realization of the PNP vision and the accomplishment of the PNP mission.
With the government intent to promote regional development in order to spur and accelerate economic growth in the countryside, Executive Order Number 682 was signed on November 22, 2007 which states among the others that the City of Calapan in Oriental Mindoro has been designated as the Regional Center of Region 4B otherwise referred to as MIMAROPA Region. On January 12, 2009 pursuant to Executive Order Number 682, the Regional Director of PRO MIMAROPA, PCSUPT LUISITO TINIO PALMERA and his Staff spearheaded the turn-over of Office equipments and facilities of its former Regional Headquarters in Camp Vicente Lim, Calamba City to PRO CALABARZON and transferred to its new Regional Headquarters at Camp Efigenio C Navarro in Barangay Suqui, Calapan City.
MIMAROPA Region is composed of five (5) provinces namely: Mindoro Occidental, Mindoro Oriental, Marinduque, Romblon and Palawan with a total land area of 27,455.9 square kilometers composed of 1,946 islands and islets. MIMAROPA Region is the largest Region nationwide in terms of land area while National Capital Region is the smallest region with 636 square kilometers. Due to its archipelagic nature, it claims to also have the largest territorial water. In terms of land area and territorial waters, MIMAROPA represents one-third of the whole Philippine archipelago. Its land area spans a north to south from tip of Lubang Island to Balabac with a distance of asa Island of Kalayaan, Palawan with a distance of approximately 770 kilometers approximately 700 kilometers and from east to west in the tip of Sibuyan Island to Pag-. The region is further subdivided into seven (7) congressional districts composed of two (2) cities and seventy one (71) municipalities with 1,491 barangays.