Model Denial of Service (Model DoS) attacks, a modern evolution of traditional DoS that targets the computational resources of AI and Machine Learning systems, rather than network bandwidth. It explains how these attacks degrade performance or render AI models unavailable, often by exploiting their processing demands or through tactics like Economic Denial of Sustainability (EDoS), which incurs substantial financial costs for victims. The text outlines the threat landscape, identifying highly vulnerable AI services like Large Language Models (LLMs), and offers a multi-layered framework for detection, prevention, and mitigation, emphasizing architectural, application-level, and operational controls to build resilient AI systems.