Child Coverage Expansions: Spillover Effects on Health Insurance Among Citizen Children in Mixed-Status Families

• In Event: Revisiting Medicaid Expansion: Uneven Effects Across Patients, Providers, and Other Insurance Markets

Abstract

Introduction
Recent children’s coverage expansions in several states have aimed to increase health insurance coverage among children regardless of immigration status. There is limited evidence on how these policies affect citizen children living in mixed-status families, who may face barriers to enrollment due to household-level constraints, administrative complexity, or fear of program participation. Understanding these spillover effects is important for evaluating the broader equity implications of inclusive coverage policies.
Research Question
This study examines whether state-level children’s coverage expansions, regardless of immigration status, are associated with changes in the uninsured rate and coverage sources among low-income citizen children in mixed-status families.
Data
We use repeated cross-sectional data from the American Community Survey (ACS) from 2012 to 2024. The main analytic sample consists of citizen children under age 18 living in mixed-status families with at least one noncitizen sibling and household incomes below the Medicaid eligibility threshold in their state of residence during the year of the interview (N= 85,993). We also conduct some analyses for noncitizen children in these same families. The data include detailed information on insurance status, demographics, and family characteristics.
Research Design and Methods
This study leverages variation in the timing of state-level children’s coverage expansions regardless of immigration status using a difference-in-differences framework. We estimate two-way fixed effects models, clustering standard errors at the state level and applying ACS person weights. Models are estimated both with and without controls for child and household characteristics, including age, race/ethnicity, family income, parental education, and employment. We also estimate event study models that replace the main expansion policy indicator with the leads and lags of state policy changes. We plan to conduct additional analyses to test the robustness of our findings, including estimating alternative models that account for heterogeneity in treatment timing.
Results
Among citizen children in mixed-status families, children’s coverage expansions were associated with a significant, 4.5 percentage point reduction in uninsurance, consistent with spillover effects within households. This decline is driven by a significant 5.0 percentage point increase in Medicaid coverage, with limited evidence of crowd-out from private coverage. Non-citizen children in mixed-status families experienced a larger increase in Medicaid coverage (13.09 percentage points), although they also experienced a decline in private coverage, resulting in a net 12.4 percentage point reduction in the uninsured rate.  Event study analyses did not reveal evidence of violations of the parallel trends assumption.
Conclusion
These findings imply that policies expanding coverage eligibility for children regardless of immigration status may have significant spillover effects among families. By improving coverage among citizen children in mixed-status families, these policies may reduce disparities in access to care and promote more equitable health outcomes. The results highlight the importance of considering household-level dynamics in the design and evaluation of public insurance programs.

Author

• Mst Sadia Sadia Sultana, University of California, Irvine
  Presenting Author