OBJECTIVES: To estimate health insurance and health care utilization patterns among previously incarcerated men following implementation of the Affordable Care Act's (ACA's) Medicaid expansion and Marketplace plans in 2014. METHODS: We performed serial cross-sectional analyses using data from the National Survey of Family Growth between 2008 and 2015. Our sample included men aged 18 to 44 years with (n = 3476) and without (n = 8702) a history of incarceration. RESULTS: Uninsurance declined significantly among previously incarcerated men after ACA implementation (-5.9 percentage points; 95% confidence interval [CI] = -11.5, -0.4), primarily because of an increase in private insurance (6.8 percentage points; 95% CI = 0.1, 13.3). Previously incarcerated men accounted for a large proportion of the remaining uninsured (38.6%) in 2014 to 2015. Following ACA implementation, previously incarcerated men continued to be significantly less likely to report a regular source of primary care and more likely to report emergency department use than were never-incarcerated peers. CONCLUSIONS: Health insurance coverage improved among previously incarcerated men following ACA implementation. However, these men account for a substantial proportion of the remaining uninsured. Previously incarcerated men continue to lack primary care and frequently utilize acute care services.