Objectives: To examine how federal noncitizen Medicaid eligibility restriction and generous state policy affect Medicaid and health insurance coverage among older adults with different citizenship status. Method: This study uses an older adult sample (65 years or older) from the Current Population Survey (CPS) and state data and employed a triple difference-in-differences approach to incorporate variations in citizenship status, time, and state eligibility. Results: Findings show that Medicaid coverage significantly declined among older noncitizens but increased among older naturalized citizens after Welfare Reform. Findings also show that the differences in older noncitizens’ health insurance coverage changes were significant between generous and nongenerous states. Discussion: Medicaid eligibility affects older immigrant adults’ Medicaid and health insurance coverage. Findings support the “protective citizenship” hypothesis but not the “chilling effect” and “labor market condition” hypotheses. Opposite patterns of change in Medicaid coverage between naturalized citizens and noncitizens raise doubt about the effectiveness of eligibility restrictions in reducing government spending.