<p>Several artificial intelligence (AI) literacy frameworks have been developed to guide what K–12 education should focus on to prepare students to be AI-literate. However, these frameworks tend to either focus heavily on technical content or fail to specify the competencies students need at each grade band to be considered AI-literate. To address this gap, this study conducted a systematic review to map AI literacy competencies, examining the focus of K–12 AI literacy and education research, the specific competencies emphasized at each grade band, and how these competencies evolve across grade bands. We reviewed 36 empirical studies and identified five components of AI literacy that have been studied so far: Understanding Foundational AI Concepts, Creating AI Artifacts, Interacting With AI Agents, Developing Awareness of AI Ethics, and Understanding Human-AI Relationships. Additionally, we found evidence of how specific AI literacy competencies associated with each of these components progress and evolve across grade bands. Our findings highlight gaps in the existing research on AI literacy in K–12 education and offer insights into the practical implications for developing AI literacy curricula that are age-appropriate and comprehensive.</p>