The purpose of this TACSEI Roadmap document is to assist a range of stakeholders (e.g., early childhood service providers, parents, technical assistance providers) understand the types of TA that are most beneficial for achieving particular practice and systems outcomes. The paper explores and highlights TA strategies to initiate, implement, and sustain effective practice and systems change. The content of this Roadmap is based on a broad literature related to practice, service, and systems change, data and information related to TA across a number of domains (e.g., special education, general education, community prevention, aid for developing countries), and data and best practices related to implementation and scaling up of evidence-based practices. (author abstract)