Although the importance of prenatal care is widely recognized, little is known about the impact of different models of care on health outcomes. We examined the relationships of setting and provider of prenatal care to birth outcomes among low-income women in a predominantly rural county in the northwest United States. Three study populations were compared: all women who received care from certified nurse-midwives (CNMs) at a hospital-based prenatal clinic; all Medicaid recipients who obtained care from CNMs in private practice; and a randomly selected sample of Medicaid recipients who obtained care from physicians in private practice. Data on sociodemographics, prenatal care use, health indicators, and birth outcomes were collected from birth certificates. When other factors known to affect birth weight were controlled through multiple regression analyses, results indicated that receiving care from CNMs and receiving care in the private setting were related to higher mean infant birth weight.