This paper contributes to evidence regarding the effectiveness of the Medicaid expansions by focusing on a key beneficiary - the mother - who has previously been overlooked. Using the Natality Detail Files for 1989-96, we estimate the relationship between Medicaid eligibility and maternal health outcomes for several treatment groups and a control group. Potential biases caused by improved reporting are addressed by using a 'straw man' maternal complication not preventable with prenatal care. Our results suggest that increased Medicaid eligibility may have led to fewer preventable maternal complications among women most likely to have benefited from the Medicaid expansions.