Surveys of state Medicaid agencies and maternal and child health programs were conducted in late 1991 and in 1992 to evaluate the extent to which states carried out a series of federal policy changes intended to improve low-income women's access to prenatal care. The results show a great deal of variability in the aggressiveness with which states implemented these Medicaid eligibility expansions. Overall, North Carolina, Maryland, Massachusetts, New York and Arkansas moved most aggressively to carry out the expansions; Kansas, Nebraska, South Dakota, North Dakota and Wyoming were ranked least aggressive. States with relatively high levels of poor birth outcomes or low-birth-weight deliveries prior to the Medicaid expansions were generally more likely than other states to have undertaken reforms intended to increase the number of women eligible for assistance and ease their enrollment. In addition, expansion efforts were greater in states where the federal government paid more of the cost of caring for Medicaid recipients.