This article describes the three-decade experience in model development and replication and in introducing and sustaining organization change of Child Development Resources (CDR), of Williamsburg, Virginia. CDR provides an integrated system of services for children with disabilities and developmental delays as well as for children who are at risk. Since 1975, CDR has successfully won and completed 29 model demonstration and outreach projects. Most models have been widely replicated and their materials used throughout the country. Listening to families and professionals define their needs is at the heart of CDR's model development. The author identifies and describes three sets of factors for successful model development and replication: (1) factors related to the model; (2) characteristics of the replication site; and (3) elements of the change or replication process used to ensure that replication will be carried out with fidelity to the original model and will achieve the anticipated results in the new site.