Which US States Are Most Generous in Their Medicaid Policies and Why?

Abstract Why are some states more generous in their welfare programs than others? Although widely studied in comparative political economy, this question has been less applied to U.S. health policy. Delegation of Medicaid administration to the states has produced substantial variation in program generosity, but the sources of this variation remain underexplained. This paper analyzes predictors of Medicaid generosity using longitudinal data from 2000–2020 on state eligibility and enrollment rules. We test several political economy theories, including left power resources, racial/ethnic heterogeneity, political culture, and partisan politics. Findings show strong variation in generosity across states and generosity categories, though overall generosity has increased over time. Political culture—particularly conservative attitudes—has the most consistent negative effect on generosity. Racial heterogeneity also suppresses generosity. By contrast, Democratic trifectas and union strength show no consistent effects, while Republican trifectas correlate with higher administrative burden and reduced eligibility, but less consistently than mass attitudes. Overall, political culture more consistently shapes Medicaid generosity than party control, suggesting that public preferences for limited government play a key role in shaping state policy. The paper concludes by discussing implications for the present moment as the scope of Medicaid coverage is poised to be dramatically reduced.