Deployment of electronic health records, including electronic medication management (EMM) systems, can resolve some errors (e.g., transcription errors) while introducing new ones. This study analyzed types of incident reports related to EMM at three hospitals over the course of its implementation. Errors were categorized by EMM design, user conditions (e.g., unfamiliarity with EMM workflow), and organization conditions (e.g., simultaneous use of paper and EMM documentation). These errors persisted despite time since EMM implementation, suggesting ongoing training and system maintenance is required.