Autonomous AI agents are transforming healthcare delivery through their expanding capabilities. This chapter examines the conceptual evolution and practical implementation of autonomy in medical AI systems. We analyze three key dimensions: technical architecture, clinical integration, and ethical governance. The technical analysis focuses on recent developments in adaptive learning systems and their validation in clinical settings. The integration section examines implementation challenges and emerging models of human-AI collaboration in healthcare workflows. The ethical analysis explores the philosophical and practical implications of using AI tools to assist with medical decisions to autonomous systems, particularly regarding accountability and patient autonomy. Drawing from empirical cases and theoretical frameworks, we propose a comprehensive model for evaluating and implementing autonomous AI agents in healthcare settings. This work aims to inform evidence-based policies for the responsible deployment of autonomous medical AI systems.