Covering America's Contingent Worker: The Effect of ACA Mechanisms on the Insurance Prospects of Part-Time Workers

Abstract

Representing 17% of the American labor force, part-time workers today are a persistent, meaningful feature of employment in the United States. Though employers are the principle source of health insurance in the US, federal law does not mandate the provision of health insurance to these contingent workers. Without guaranteed access to employer-sponsored insurance and traditionally excluded from government health care programs exclusively targeting the very poor, part-time workers face stark health insurance insecurity.

This thesis builds on previous studies to examine how key Affordable Care Act (ACA) reforms affected insurance outcomes for part-time workers, who are more likely to be low-income than their full-time counterparts (based on wage differentials and other part-time penalties). In 2014, 26 states elected to expand Medicaid eligibility to 138% of the Federal Poverty Line under ACA reform. By 2016, an additional 6 states had chosen to expand.

This thesis uses a logistic difference-in-differences regression to assess the causal impact of this Medicaid eligibility expansion on the probability that part-time workers had insurance. This analysis also examines the impact of Medicaid expansion on the probability of Medicaid, employer, and non-group coverage in this population. Secondarily, this thesis tests the hypothesis that part-time workers in states that refused to expand Medicaid relied on marketplace coverage more than those workers in expansion states. A qualitative review of interviews with enrollment assisters explores the efficacy of these mechanisms from a community-level perspective.

The results show that Medicaid expansion was associated with a statistically significant increase in the probability that part-time workers had insurance in expansion states. Expansion was also associated with an increase in the probability of Medicaid coverage, evidencing the undiluted impact of the eligibility adjustment on intended recipients. The model suggests that Medicaid expansion did not affect the probability of coverage through an employer. Additionally, 2018 data shows that part-time workers in non-expansion states utilized marketplace coverage more than those workers in expansion states, though the majority of these workers relied on subsidized coverage. The interviews affirm the importance of ACA mechanisms in providing health insurance to part-time workers. They also provide invaluable insight into the effective deployment of assisters as outreach tools that facilitate enrollment.

Based on these findings, the thesis concludes that Medicaid expansion in remaining non-expansion states is a critical objective. Secondly, the thesis proposes that levels of funding for outreach should increase to restore and enlarge enrollment assistance programs. Enrollment assisters have a decisive impact by directing to and enrolling part-time workers in coverage, preventing these workers from falling through the cracks in a highly fragmented health insurance system.