CONTEXT: The 2010 Patient Protection and Affordable Care Act (ACA) eliminated the restrictions on preexisting conditions for health care coverage. Little is known about the effects of the ACA on health care access among individuals with chronic health conditions. OBJECTIVE: To determine how the implementations of the ACA affected health care access for adults with chronic health conditions. DESIGN, SETTING, AND PARTICIPANTS: Data from respondents aged 18 to 64 years to the 2011-2017 nationally representative Behavioral Risk Factor Surveillance System (BFRSS) who reported preexisting chronic health conditions (n = 1 133 609). Multivariable logistic regression models were used to examine the changes in health care access from 2011-2013 (before the ACA) to 2015-2017 (after the ACA), overall and by sociodemographic groups. MAIN OUTCOMES MEASURES: Self-reported access to health care coverage, skipped doctor visits because of cost issues, and having a routine checkup in the past 12 months. RESULTS: The percentage of adults with chronic health conditions having no health care coverage declined from 19.7% before the ACA to 11.9% after the ACA (adjusted odds ratio [AOR] = 0.5], P < .001), the percentage of skipped doctor visits because of cost declined from 24.6% to 20.0% (AOR = 0.8, P < .001), and the percentage with an annual routine checkup increased from 69.6% to 72.5% (AOR = 1.1, P < .001). The improvements in health care access were pronounced across sociodemographic groups after the ACA, especially among some disadvantaged groups (ie, young adults, non-Hispanic Blacks and Hispanics, and those with low income and low education). However, substantial disparities in health care access persisted, especially among individuals with low socioeconomic status. CONCLUSIONS: This study identifies substantial improvements in health care access among adults with chronic health conditions after ACA implementation, especially among disadvantaged populations.