Early intervention for infants and toddlers with disabilities was established as a national commitment in the form of federal legislation in 1986. Since then, we have witnessed steady growth in the number of children and families served, although the most recent report to Congress indicates that only about 1.7% of the population of infants and toddlers is served in early intervention programs. All states and territories currently are participating in this optional program. Federal regulations stipulate the components of an early intervention system that must be in place if states are to receive federal funding. However, a great deal of flexibility is allowed in how these broad regulations are implemented, resulting in considerable cross-state variability in who is served and the amount and type of services received. This article describes the current status of early intervention and discusses five issues we believe to be critical in the coming decade: (1) determining the outcomes expected of early intervention; (2) determining appropriate models and intensity of treatments; (3) factoring quality into the efficacy equation; (4) accounting for child, family, and community variables in determining efficacy; and (5) integrating emerging perspectives and knowledge from neuroscience and genetics. MRDD Research Reviews, 1999; 5:11–20. © 1999 Wiley-Liss, Inc.
