For decades, leaders and scholars have been advocating change efforts to improve work-life relationships. Yet most initiatives have lacked rigor and not been developed using scientific principles. This has created an evidence gap for employer support of work and personal life as a win-win for productivity and employees' well-being. This paper examines the approach used by the U.S. Work Family Health Network (WFRN) to develop an innovative workplace intervention to improve employee and family health. The change initiative was designed to reduce organizationally based work-family conflict in two contrasting contexts representative of major segments of today's U.S. workforce: health care employees and informational technology professionals. The WFRN Intervention (called STAR) had three theoretically based change elements. They were: 1) increase job control over work time and schedule; 2) increase supervisor social support for family and job effectiveness; and 3) improve organizational culture and job design processes to foster results orientation. Seven practical lessons for developing work-life interventions emerged from this groundbreaking endeavor.