Current theoretical models and electrochemical techniques used to investigate corrosion mechanisms, including corrosion rates, have been tailored for conventional alloy systems. However, the application of conventional theories and techniques toward next-generation alloys such as multi-principal element alloys and additively manufactured alloys needs to be revisited due to the increased chemical complexity and refined microstructures of these alloys, which may yield different electrochemical properties from the conventional alloys. This review aims to discuss to which extent the current models and techniques used in corrosion science can be applied to these new alloy systems, and outline some of the challenges that need to be overcome to accurately describe their electrochemical reactivity.