INTRODUCTION: Efforts to reduce maternal mortality in the U.S. have increasingly focused on the postpartum period. Currently, federally mandated Medicaid provision during pregnancy up to 6 weeks postpartum covers nearly half of the births in the U.S. However, 17.5% of pregnancy-related deaths occur between six-weeks and one-year postpartum, primarily due to cardiomyopathy (32.4%), mental health conditions (16.2%) and embolism (10.8%). METHODS: In April 2019, ACOG redefined the postpartum period as the "fourth trimester," recommending care be "an ongoing process rather than a single encounter." In June 2019, the AMA joined ACOG in supporting expansion of Medicaid coverage to 12 months postpartum. The Illinois state legislature approved expansion of Medicaid coverage to 12 months postpartum during its budget reconciliation process in 2019. RESULTS: Data from the ACA's Medicaid expansion indicates that postpartum Medicaid expansion would significantly impact health outcomes. By reducing the income eligibility for Medicaid, women who previously only qualified for Medicaid in pregnancy can now remain insured after 6 weeks postpartum. Expansion states had 1.6 per 100,000 fewer maternal deaths than non-expansion states. Postpartum Medicaid expansion will also allow for better birth spacing, improved mental health care, and longer follow-up for medical complications of pregnancy. CONCLUSION: Changing the paradigm of postpartum care provision could drastically impact maternal mortality. The consensus of support from the AMA and ACOG around expansion of Medicaid to 12 months postpartum is a critical step forward for legislative efforts to address maternal mortality. As with Illinois, obstetrician-gynecologists should advocate for policy alternatives that support increased access to postpartum care.