The Impact of Changes in Medicaid Eligibility Thresholds on Duration of Health Insurance Coverage and Access to Health Care

Monday, June 11, 2018: 10:20 AM
Azalea - Garden Level (Emory Conference Center Hotel)

Presenter: Heather Dahlen

Co-Authors: Sharon K. Long; Michel Boudreaux

Discussant: Marguerite Burns


The primary goal of the Affordable Care Act (ACA) is to provide more Americans access to affordable, quality health insurance. The Medicaid expansion is one component of the ACA designed to improve access to the health care system for individuals with low incomes. Beginning in 2014, states had the option to expand Medicaid eligibility to individuals with incomes up to 138% of the federal poverty level (FPL), regardless of parental status. By the end of 2016, Medicaid insured 72.7 million individuals, an increase of nearly 11 million since 2014. Unlike many private insurance plans, when an individual enrolls in Medicaid they are not automatically eligible for coverage for the next 12 months, and may lose eligibility and coverage due to events like failing to submit verification paperwork, finding a job that offers coverage, or increases in income.

The expansion of Medicaid income eligibility thresholds provides additional protection against such losses of eligibility which, in theory, should improve how many months of the year the individual is insured. The analysis will address two research questions: 1. Does expanded Medicaid eligibility lead to greater continuity of insurance coverage? 2. Does greater continuity of coverage lead to better access to care?

Data and Methods

To answer these questions, we take advantage of the differences across the states in Medicaid income eligibility thresholds and decisions on implementing the ACA’s Medicaid expansion. With data from the National Health Interview Survey (NHIS), we use state-level Medicaid thresholds as instruments for coverage duration to produce causal impacts of the effect of coverage duration on health care access, utilization, and affordability measures, including: usual source of care; emergency department use; foregone medical care due to cost; delayed care due to cost; medical bills and debt; and visits to a medical provider. Because the analysis requires state-level information and imputed continuous income, we requested and received the restricted NHIS file which contains this information and are conducting the analysis in the Minnesota Census Research Data Center (RDC) at the University of Minnesota.


Preliminary findings using data through 2015 suggest expanded Medicaid eligibility improves coverage duration and access to care. The authors are currently producing estimates using 2016 data, which provides additional post-health reform information for their analytic target, the Medicaid expansion population.


This analysis is particularly timely, given the extent to which Medicaid expansion states are increasingly considering modifications to their Medicaid programs under Section 1115 expansion waivers, including modifications that place new restrictions on eligibility.