This research brief is the first in a series which seeks to provide early childhood researchers, program developers, and funders with an introduction to implementation frameworks and promising practices in implementation science with the aim of facilitating their use in early care and education. This brief introduces key elements of effective implementation within an integrated, stage-based framework. This framework posits that 1) implementation happens in four discernible stages; and 2) three common “threads” or core elements exist across each of these stages. The brief defines these three common elements, demonstrates their basis in previous syntheses of the implementation science literature, and describes the way these elements function at each stage of implementation. This brief includes illustrative examples of how this integrative, stage-based framework can be used by early childhood program developers, researchers, and policymakers. An appendix shares a planning tool that captures key activities and questions that arise at each stage for each of the three core implementation elements.