&NA;In the last several decades, the importance of early intervention has been recognized and institutionalized through federal and state laws and regulations. Challenges for policy makers, personnel preparation specialists, and administrators of service programs include the newness of this field, the complexity of the service delivery system, the range of families and children served, the multidisciplinary nature of the services provided, and the variability from state to state. Key implementation issues must be addressed if we are to realize optimal services for infants, toddlers, and their families. This article focuses on implementation concerns and recommendations related to addressing the needs of the wide range of children and families to be served and providing services in natural environments, as well as issues of personnel preparation and models of service delivery.