Surprise out-of-network (OON) bills can represent a considerable cost burden on patients. However, OON billing remains underexplored in elective, outpatient surgery procedures, which have greater latitude for patient choice. We aimed to answer the following questions: (1) What is the prevalence and magnitude of OON charges in hand surgery? (2) What are the sources of OON charges? and (3) What factors are associated with OON charges?