Electronic Health Record (EHR) and Personal Health Record (PHR) systems could allow patients to better manage their health information and share it to enhance the quality and efficiency of their healthcare. Unfortunately, misuse of in-formation stored in EHR and PHR systems will create new risks for patients, and we need to empower them to safeguard their health information to avoid problems such as medical identity theft. In this paper, we introduce the notion of ac-countable use and update of electronic health records and design a patient-centric monitoring system based on it. We develop a system architecture and associated protocols that enable either explicit or implicit patient control over when and how health information is accessed. Our approach pro-vides a reasonable solution rather than addressing the more general information flow control problem in distributed sys-tems. We also implement and evaluate a prototype sys-tem motivated by a health record sharing scenario based on NHIN Direct to demonstrate that enhanced accountability can be supported with acceptable performance and integra-tion overheads.