Elderly care receivers are extensively and profoundly affected by interacting with care robots. This paper focuses on autonomy as a core value in elderly care and demonstrates its complexity. Few studies have been able to address this complexity in elderly care in the robot era. Therefore, a taxonomy of autonomy is introduced to discern the complexity and tailored as a tool to evaluate ethical aspects of the effects of care robots on autonomy in elderly care. It concludes that this taxonomy is instrumental for impact assessments of care robots on care receivers’ autonomy both retrospectively and prospectively.