Mixed Eligibility and the Affordable Care Act, Healthcare Access and Utilization for Children with Mixed Eligible Siblings

Public health insurance for low income children in the US is primarily available through Medicaid and CHIP.  Combined, these programs extend eligibility to most children under 200 percent of the Federal Poverty Guidelines (FPG) nationwide and have been effective in reducing the number of uninsured children under 19 over the past two decades.  In most states, Medicaid and CHIP are run as two separate programs with income eligibility thresholds for Medicaid varying by a child’s age.  This results in a phenomenon called “Mixed Eligibility”, where multiple children in the same family may be eligible for different public insurance programs.  Research has shown that children with mixed eligible siblings are less likely to enroll in public insurance when their state runs Medicaid and CHIP as separate programs.  The Affordable Care Act (ACA) seeks to decrease the incidence of mixed eligibility across siblings by requiring all states with Separate CHIP programs to convert children in families below 138% FPL to Medicaid CHIP, a change that will likely result in increased take-up among eligible children in affected families. 

This paper identifies another dimension in which the ACA CHIP requirement is likely to impact families, increasing their access to and utilization of healthcare services.  We will investigate the hypothesis that mixed eligibility affects healthcare access and utilization because (1) eligible, but un-enrolled children are less likely to seek care and (2) families with children enrolled in both programs may find it difficult to navigate two separate healthcare systems to obtain care for their children.  The paper presents estimates of the impact of mixed eligibility on children’s healthcare access and utilization in the Pre-ACA period and then simulates the ACA MCHIP conversion policy to estimate its potential impact on take-up, access and utilization.              

We use MEPS data between 2001 and 2011 on low income children under 19.  Family level characteristics combined with state and year specific rules on program eligibility allow us to simulate Medicaid and CHIP eligibility for each child (and their siblings) using Pre-ACA and Post-ACA rules.  We observe children’s access and utilization with MEPS measures on usual source of care, office visits, outpatient visits, ER visits and dental visits and identify whether children with any mixed eligible siblings have a weaker attachment to the healthcare system than children with only uniform eligible siblings.  We also shed light on whether the differences in access and utilization can be attributed to their increased likelihood of being eligible, but un-enrolled or to the difficulty families may face in obtaining care when their children are enrolled in two different provider systems.

Preliminary regression results show that children with mixed eligible siblings are significantly less likely to have a usual source of care and are less likely to have any dental visits in states with Separate CHIP programs compared to those in states with Medicaid Expansion CHIP programs.  Differences can be attributed to both mechanisms; their increased likelihood of being uninsured and the potential difficulty of families with enrolled children to navigate multiple provider systems.