Effect of Losing Public Health Insurance on Self-Reported Mental Health

Much is known about gaining health insurance, but little is known about losing it. This study investigates how losing public health insurance impacts mental health, using Tennessee’s 2005 TennCare disenrollment as a natural experiment. When the state abruptly cut Medicaid coverage for nearly 200,000 low-income, childless adults, it created a rare opportunity to examine the effects of coverage loss at scale. Drawing on individual-level data from the Behavioral Risk Factor Surveillance System (BRFSS) between 2000 and 2010, I apply a difference-in-differences approach, comparing trends in Tennessee to 38 control states that maintained stable Medicaid eligibility rules. The analysis finds that losing coverage led to a significant 17.5 percentage point increase in poor mental health, a nearly 80% rise relative to baseline. The effects were most severe among women, older adults, the unemployed, and those without a college degree. Mechanism analyses show that coverage loss reduced insurance rates, increased cost-related barriers to care, and decreased preventive service use. This study offers the first causal evidence linking large-scale public insurance loss to worsening mental health and highlights important implications for health policy and Medicaid program.