DESCRIPTION: Although it is frequently advocated, that children with chronic or complex medical conditions should have a "medical home", there is remarkably little empirical information in the literature about what (or who) constitutes a medical home and the extent to which children with chronic conditions actually have medical homes. The aims of this project are: 1. To develop operational definitions that can be used with claims data to identify a child?s "medical home"; 2. To characterize the kinds of providers that serve as medical homes for children with chronic diseases; 3. To determine whether demographic and medical severity factors are associated with a) having a medical home and b) with having certain kinds of providers serving as medical homes; 4. To determine whether certain kinds of health insurance types a) promote the establishment of a medical home and b) promote certain kinds of providers serving as medical homes. Claims data from Medicaid and from three of Washington States largest private health plans, on approximately 30,000 children with either asthma, diabetes, cerebral palsy, or low birth weight will be used to develop a measure of "medical home" and to study the relationships between demographic factors, disease severity, and plan features and the use of medical homes by children with chronic conditions.