Recent reforms in federal legislation have made Medicaid-financed prenatal care available to pregnant women from households at nearly twice the poverty level. Census and birth certificate data provide little information about the newly eligible group beyond estimates of their size. This article reports on efforts to compare the Medicaid expansion group to traditional Medicaid prenatal care patients in terms of demographics, access problems, and prenatal care adequacy by employing a short-term, hospital-based survey of postpartum women in Michigan. Differences between pregnant women eligible under the expansions and traditionally eligible pregnant women suggested that major changes in outreach and enrollment activities of state Medicaid agencies may be necessary to fulfill the opportunity represented by the Medicaid expansions.