The COVID-19 pandemic had the potential to alter patterns of health insurance coverage in the US. Using data from the Medical Expenditure Panel Survey, we found increased stability of Medicaid coverage for children and nonelderly adults during the first year of the pandemic. Fewer people who had Medicaid in 2019 became uninsured in 2020 (4.3 percent) than in 2018-19 (7.8 percent).