In 1919, the boundary dispute between Calapan and Naujan was adjudicated by Presidentes (Mayors) Agustin Quijano of Calapan and Agustin Garong of Naujan over a portion of the territory of what is now known as the present boundary.
In the year 1998, Calapan was converted from a municipality into a component city by virtue of Republic Act No. 8475.