Low-income parents experienced significant expansions of Medicaid eligibility under the Affordable Care Act (ACA). We used data for the period 2010–15 from the National Health Interview Survey to examine the impacts of the ACA’s Medicaid expansion on coverage, access and use, affordability, and health status for low-income parents. We found that eligibility expansions increased coverage, reduced problems paying medical bills, and reduced severe psychological distress. We also found that low-income parents in nonexpansion states would have experienced an additional 28 percent drop in their uninsured rate if those states had opted into the ACA Medicaid expansion.