A switchable metal insulator metal capacitor (MIMcap) and a method for fabricating the MIMcap. In another aspect of the invention operating the MIMcap is also described. A first capacitor plate and a second capacitor plate are separated by a capacitor dielectric and disposed over a substrate. A first via is electrically connected to the first capacitor plate and comprised of phase change material (PCM). The PCM is deposited in an electrically conductive state and convertible by application of heat to an insulating state. A first heater is proximate to and electrically isolated from the PCM in the first via. When the first heater is activated it converts the PCM in the first via to the insulating state. This isolates the first capacitor plate from an integrated circuit.