This brief outlines both the national and state environments and summarizes the opportunities and challenges that need to be taken into account as states move forward to develop comprehensive early childhood systems. It is adapted from and summarizes a full report entitled "Planning for the State Early Childhood Comprehensive Systems Initiative (SECCS): An Environmental Scan of Opportunities and Readiness for Building Systems." That full report examines how each of the five components of the initiative (medical home, parenting education, early care and education, family support, and mental health) are positioned on the national policy landscape and outlines key resources available to states during their planning process. The full report also analyzes how ongoing activities in the MCH community relate to the goals of the SECCS Initiative. Also described are ways in which some of the promising practices and policy initiatives of potential partnering agencies and programs (such as education) create an opportunity for synergies. These internal and external environments shape the options available to states, desired results, and chances of success. The present brief discusses in detail the most frequently cited challenges to systems building with the SECCS Initiative. These include financing, data collection and monitoring, engaging and integrating multiple service sectors, and planning and technical assistance.