The effect of 20 MeV electron radiation on the lifetime of the silicon carbide power MOSFETs was investigated. Accelerated constant voltage stress (CVS) was applied on the pristine and irradiated devices and time-to-breakdown ( T BD ) and charge-to-breakdown ( Q BD ) of gate oxide were extracted and compared. The effect of electron radiation on the device lifetime reduction can be observed at lower stress gate-to-source voltage ( V GS ) levels. The models of T BD and Q BD dependence on the initial gate current ( I G0 ) are proposed which can be used to describe the device breakdown behaviour.