Information gathered via rigorous exploration of risk factors for inadequate preventive service receipt in inner city children is especially important at present, because despite rising immunization rates around the country, it is clear that “pockets of need” remain in many urban locations. Children in these pockets of need, in addition to being under-immunized, also are at higher risk for lack of other preventive services, and suffer from higher rates of iron deficiency anemia and lead poisoning. The knowledge gained from both the descriptive and interventional parts of the study will provide crucial information for physicians who care for these children, health care systems that serve them, and policy makers responsible for promoting effective tools and funding their implementation. The information gained herein will also provide important methodological insight for generalists who wish to conduct interventional studies in large urban populations, by further refining existing methods used in design and implementation of large cohort studies in disadvantaged children.