Effects of State-Level Medicaid Expansion Decisions on Medicaid and Public Health Insurance Enrollment
David Steffen
This project sought to understand and visualize the impact of the Medicaid expansion that began in 2014
after the passage of the Affordable Care Act in 2010 and as part of its subsequent implementation, and
especially the impact of the decisions by certain states not to expand Medicaid. The Medicaid expansion
primarily targeted adults, and especially childless adults, with incomes below 138% of the Federal
Poverty Level (FPL). As a result, this project sought to explore:
How important is Medicaid to the provision of public health insurance, and how important was
the expansion to the provision of public health insurance to people of different income levels?
What impact did not expanding Medicaid have on the proportion of people with low incomes who
are able to access Medicaid and other public health insurance programs?
How did expansion impact access to Medicaid by age, and how did expansion affect the age makeup
of states' Medicaid caseloads? How do these now differ from non-expansion states, if at all?
How have these impacts changed over time, if at all?
The primary data source for these analyses was the annual American Community Survey. These datasets are available at data.census.gov, and are publicly accessible.
Key datasets I used included:
B27001 Health Insurance Coverage Status by Sex by Age
B27007 Medicaid/Means-Tested Public Coverage by Sex by Age
B27010 Types of Health Insurance Coverage by Age
S2704 Public Health Insurance Coverage by Type and Selected Characteristics
For state expansion decisions, I used a Kaiser Family Foundation dataset:
Status of State Action on the Medicaid Expansion Decision