A new brief from SHADAC defines a “primary source of coverage hierarchy,” and how and when researchers can use this tool to determine which payer is primary when an individual reports multiple sources of health insurance coverage on the American Community Survey (ACS).

Using a hierarchy provides multiple benefits for researchers, including the ability to ensure that individuals who report having multiple types of coverage are only counted once, reducing the rate of over-reporting for a specific type of coverage, and making coverage estimates more comparable across different surveys. However, SHADAC researchers caution that there is not one specific, singular hierarchy that should always be imposed; rather, there are a multiplicity of possible hierarchies with orders of coverage varying based on the research focus and requirements of each individual analysis (e.g., if a researcher would like to look at a range of coverage over time, or examine coverage for a singular year or specific subpopulations).

When performing national, state, and sub-state analysis of ACS coverage data, SHADAC imposes a particular coverage hierarchy that places respondents into two categories, age 0-18 and age 19 and older, and then ranks possible coverage options—Medicare, Medicaid/CHIP, Employer/Military (TRICARE, VA), Direct purchase, and Uninsured —in descending order for which respondents in each age group will be sorted.

The reason for this separation by age is that for all adults age 19 and older, Medicare is considered the primary source as it is the primary payer for covered medical services. Children age 0-18 are not eligible for Medicare (except in one rare and specific instance) and therefore Employer/Military is considered primary, as many dependents draw this source of coverage from an adult parent or caregiver.

In addition to exploring the different hierarchy possibilities, the brief also walks the user through an example application of SHADAC’s coverage hierarchy on data from the 2017 American Community Survey, and how this affects the rates of reported coverage for each insurance source for the two age groups, both separately and together.

For more on the data produced using SHADAC’s primary source of coverage hierarchy, visit our State Health Compare web tool and explore the “Health Insurance Coverage Type” measure.

Download a PDF of SHADAC’s Coverage Hierarchy for American Community Survey (ACS) Estimates on State Health Compare brief.