Although this project will be conducted among a population of disadvantaged inner city children, many of the findings from these studies will likely be applicable in health care systems that serve other socioeconomic groups. All primary care physicians who care for children face the challenge of trying to boost childhood immunization rates over 90%, and to increase the delivery of a full spectrum of preventive health services to children. The investigators hope that the evidence from this project will inform and shape both the clinical practice of individual health care providers and health care systems charged with providing preventive health care to children in a wide variety of settings.