During 1970-1992, total lengths of hospital stay following delivery declined substantially for both mothers and newborn infants. In response to public perceptions that postpartum stays have become excessively short, 28 states have enacted legislation and the U.S. Senate is considering legislation mandating that insurers provide health-care coverage for a minimum postpartum length of stay for both mother and infant. One June 28, 1995, New Jersey enacted legislation requiring insurance companies and health-maintenance organizations (HMOs) to pay for at least a 48-hour postpartum hospital stay for women and newborns following vaginal delivery and a 96-hour postpartum stay following cesarean delivery when requested by the mother or the attending physician. To assess the effect of this law in New Jersey on the average length of stay for uncomplicated deliveries, electronic birth certificate (EBC) data findings, which demonstrate that, following enactment of legislation, the average length of stay increased for uncomplicated deliveries at these four hospitals.