Silicon carbide power semiconductor devices are capable of increasing the power density of power electronics systems [1, 2]. In recent years, devices rated to block voltages up to 20 kV have been demonstrated . These research grade devices must be fully characterized to determine operating characteristics as well as failure mechanisms. The purpose of this paper is to demonstrate the continuous switching performance of ultra-high voltage metal oxide semiconductor field effect transistors (MOSFET) rated for 15 kV / 10 A. A high voltage boost converter was developed to evaluate the continuous switching performance where the high-voltage MOSFET is utilized as the main switching element. During operation, the on-state voltage, gate leakage current, and dc characteristics are monitored to determine device degradation. Measured device degradation is presented as a comparison of initial and final dc characterization.