Direct air carbon capture and storage (DACCS) involves a set of approaches for capturing CO2 directly from the air and its subsequent long-term storage. DACCS is at an early stage of technical development and currently faces a variety of challenges, including high cost and energy requirements. Building on publicly available data, this paper provides: (i) an overview and classification of DACCS systems, (ii) a harmonization of technical and economic performance of direct air capture technologies, (iii) a comprehensive list of technical- and infrastructure-based obstacles to scaling DACCS systems, and (iv) a roadmap and list of priority initiatives for research, development, demonstration, and deployment of DACCS. Our intent is to drive progress against high-impact priority actions, with a focus on accelerating research, development, and deployment of safe, scalable, and low cost DACCS as a component of the broader carbon dioxide removal portfolio.