The purpose of this article is to describe the extent to which certified nurse-midwives (CNMs) provide care to vulnerable populations in the United States and the source of reimbursement for this care. The data were obtained from the first phase of a national study to address the characteristics of women served and cost of care provided by CNMs. Results were analyzed nationally and by American College of Nurse-Midwives regions. Certified nurse-midwives in all types of practices are providing care to women from populations that are vulnerable to poorer than average outcomes of childbirth because of age, socioeconomic status, refugee status, and ethnicity. Ninety-nine percent of CNMs report serving at least one group of vulnerable women, and CNMs in the inner city and rural practices serve several groups. The vast majority of CNMs are salaried; only 11% receive their primary income from fee-for-service. Fifty percent of the payment for CNM services is from Medicaid and government-subsidized sources whereas less than 20% comes from private insurance. Source of income varies by type of setting in which the CNM attends births. The results suggest that CNMs, as a group, make a major contribution to the care of vulnerable populations.