People of color face longstanding and persistent disparities in accessing health coverage that contribute to greater barriers to care and poorer health outcomes. The Affordable Care Act (ACA) Medicaid expansion to adults with incomes at or below 138% of the federal poverty level (FPL) makes many uninsured adults of color newly eligible for the program, which would help increase their access to care and promote greater health equity. However, in states that do not implement the ACA Medicaid expansion, poor adults fall into a coverage gap and will likely remain uninsured. This brief examines the impact of this coverage gap by race and ethnicity and finds that it disproportionately impacts poor uninsured Black adults, which may contribute to widening disparities in health and health care over time.