“Childbirth is the leading cause of hospital admission in the United States, yet there has been little research on variation in hospital costs associated with childbirth. Using data from the 2011 Nationwide Inpatient Sample, we characterized the variation in estimated facility costs of hospitalizations for low-risk childbirth across US hospitals. We found that the average estimated facility cost per maternity stay ranged from $1,189 to $11,986 (median: $4,215), with a 2.2-fold difference between the 10th and 90th percentiles. Estimated facility costs were higher at hospitals with higher rates of cesarean delivery or serious maternal morbidity. Hospitals having government or nonprofit ownership; being a rural hospital; and having relatively low volumes of childbirths, low proportions of childbirths covered by Medicaid, and long stays also had significantly higher costs. The large variation in estimated facility cost for low-risk childbirths among hospitals suggests that hospital practices might be an important contributor to variation in cost and that there may be opportunities for cost reduction. The safe reduction of cesarean deliveries, increasing the coordination of care, and emphasizing value of care through new payment and delivery systems reforms may help reduce hospital costs and cost variation associated with childbirth in the United States.” doi: 10.1377/hlthaff.2014.1088 Health Aff July 2015 vol. 34 no. 7 1212-1219.