The purpose of this study was to estimate the aggregate annual costs of maternal and infant health care and to describe the flow of funds that finance that care. Estimates of costs and financing based on household and provider surveys, third-party claims data, and hospital-discharge data were combined into a single, best estimate. The total cost of perinatal care in 1989 was $27.8 billion, or $6850 per mother-infant pair. Payments made directly by patients or third parties for this care totaled $25.4 billion, or about 7 percent of personal health care spending by the nonaged population. Payments were less than costs because they did not include a value for direct delivery care or for bad debt and charity care, which accounted for $2.4 billion. Private insurance accounted for about 63 percent of total payments, and Medicaid accounted for 17 percent of the total. National health reform would provide windfall receipts to hospitals, which would receive payment for the considerable bad debt and charity care they provide. Reform might also provide short-term gains to providers as private payment rates are substituted for those of Medicaid.