Switching between different medications is common in clinical practice and can be due to a number of different factors (e.g., negative side effects and generic entry into the market); however, less is known about how administrative data studies measure drug switching when using pharmacy claims data. Unlike other measures in pharmacoepidemiology that have well-established methodological approaches (e.g., measures of compliance and persistence), the methods for measuring medication switching remain poorly characterized. Therefore, the aim of this scoping review is to describe how studies leveraging pharmacy claims data have measured drug switching in order to create a repository of common methods and highlight areas for future research.