With the emergence of "pay for success" programs, state and local governments have new opportunities to align services and demonstrate how service delivery investments in one system can improve outcomes in others and potentially save money. Integrated data systems that track individuals and families across different agencies are proving invaluable in these new efforts as well as in more traditional approaches to service coordination. This brief explores how one county -- Cuyahoga County, Ohio -- used an integrated data system (IDS) to develop an innovative pay for success program to serve a particularly vulnerable population: homeless mothers who have children in the child welfare system. The goal of Partnering for Family Success (Family Success) is to provide a more coordinated system of care that reduces the time children of homeless mothers spend in foster care. Family Success provides housing and supports that help mothers reunite more quickly with their children or allow the child to enter an alternative permanent placement.