Income Eligibility Thresholds, Premium Contributions, and Children's Coverage Outcomes: A Study of CHIP Expansions

Abstract

To understand the effects of Children's Health Insurance Program (CHIP) income eligibility thresholds and premium contribution requirements on health insurance coverage outcomes among children. 2002-2009 Annual Social and Economic Supplements of the Current Population Survey linked to data from multiple secondary data sources. We use a selection correction model to simultaneously estimate program eligibility and coverage outcomes conditional upon eligibility. We simulate the effects of three premium schedules representing a range of generosity levels and the effects of income eligibility thresholds ranging from 200 to 400 percent of the federal poverty line. Premium contribution requirements decrease enrollment in public coverage and increase enrollment in private coverage, with larger effects for greater contribution levels. Our simulation results suggest minimal changes in coverage outcomes from eligibility expansions to higher income families under premium schedules that require more than a modest contribution (medium or high schedules). Our simulation results are useful counterpoints to previous research that has estimated the average effect of program expansions as they were implemented without disentangling the effects of premiums or other program features. The sensitivity to premiums observed suggests that although contribution requirements may be effective in reducing crowd-out, they also have the potential, depending on the level of contribution required, to nullify the effects of CHIP expansions entirely. The persistence of uninsurance among children under the range of simulated scenarios points to the importance of Affordable Care Act provisions designed to make the process of obtaining coverage transparent and navigable.