We study the role of access to health insurance coverage as a determinant of individuals' subjective well-being (SWB) by analyzing large-scale healthcare reforms in the United States. Using data from the Behavioral Risk Factor Surveillance System and Panel Study of Income Dynamics, we find that the 2006 Massachusetts reform and 2014 Affordable Care Act Medicaid expansion improved the overall life satisfaction of Massachusetts residents and low-income adults in Medicaid expansion states, respectively. The results are robust to various sensitivity and falsification tests. Our findings imply that access to health insurance plays an important role in improving SWB. Without considering psychological benefits, the actual benefits of health insurance may be underemphasized.