There are ∼443 000 children in child protective custody (ie, foster care) in the United States. Children in protective custody have more medical, behavioral, and developmental problems that require health care services than the general population. These health problems are compounded by poor information exchange impeding care coordination. Health care providers often do not know which of their patients are in protective custody and are not privy to the critical social history collected by child protective services, including placement history and maltreatment history. Meanwhile, the custodial child protection agency and designated caregivers (ie, foster caregivers and kinship providers) often lack vital elements of the health history of children in their care, which can result in poor health care delivery such as medication lapses, immunization delay, and poor chronic disease management. In this case study, we address this critical component of health care delivery for a vulnerable population by describing a process of developing an information sharing system between health care and child welfare organizations in collaboration with child protection community partners. Lessons learned include recommended steps for improved information sharing: (1) develop shared community vision, (2) determine shareable information components, (3) implement and analyze information sharing approaches, and (4) evaluate information sharing efforts. A successful example of advocating for improvement of information sharing for youth in protective custody is explored to highlight these steps. In collaboration with child protective services, pediatricians can improve information sharing to impact both health care delivery and child protection outcomes.