Organizations encounter great difficulties in maintaining high-quality Access Control Policies (ACPs). Policies originally modeled and implemented with good quality deteriorate over time, leading to inaccurate authorization decisions and reduced policy maintainability. As a result, security risks arise, delays prevent users from carrying out tasks, and ACP management becomes more expensive and error-prone. In contrast to the initial modeling of ACPs, their long-term maintenance has been addressed scarcely by existing research. This work addresses this research gap with three contributions: First, we provide a detailed problem analysis based on a literature survey and six real-world practitioner expert interviews. Second, we propose a framework that supports organizations in implementing and performing ACP maintenance. Third, we present a maintenance case study in which we implemented maintenance capabilities for a real-world ACP dataset that allowed us to significantly improve its quality.