The introduction of higher voltage-rated semiconductor devices has created a new emphasis on operating voltage as part of the inductor selection process. Inductors once considered optimized for high current, low voltage applications are finding homes in new designs that apply higher voltage stress to the inductor. Replacement of silicon MOSFETs by gallium nitride (GaN) and silicon carbide (SiC), has enabled circuit operation directly from higher voltages, and newer energy sources such as 48 V automotive batteries instead of traditional 12 V systems have driven the need to more carefully consider inductor operating voltage. This whitepaper discusses operating voltage ratings for inductors.