Objectives. To evaluate the effect of the Affordable Care Act (ACA) on US veterans' access to care.Methods. We used US Behavioral Risk Factor Surveillance System data to compare measures of veterans' coverage and access to care, including primary care, for 3-year periods before (2011-2013) and after (2015-2017) ACA coverage provisions went into effect. We used difference-in-differences analyses to compare changes in Medicaid expansion states with those in nonexpansion states.Results. Coverage increased and fewer delays in care were reported in both expansion and nonexpansion states after 2014, with larger effects among low socioeconomic status (SES) and poor health subgroups. Coverage increases were significantly larger in expansion states than in nonexpansion states. Reports of cost-related delays, no usual source of care, and no checkup within 12 months generally improved in expansion states relative to nonexpansion states, but improvements were small; changes were mixed among veterans with low SES or poor health.Conclusions. Increases in insurance coverage among nonelderly veterans after ACA coverage expansions did not consistently translate into improved access to care. Additional study is needed to understand persisting challenges in veterans' access to care.