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SHADAC's Health Insurance Unit (HIU): Issue Brief, Code, and Defining Families for Studies of Health Insurance Coverage

SHADAC Staff
July 20, 2023

This is the most up-to-date version of SHADAC’s Health Insurance Unit (HIU) and Defining Families Issue Brief. Page updated 12/9/2025.

In 2012, the SHADAC “Health Insurance Unit,” or “HIU,” was created in order to aid researchers in reconciling the differences between the way that a “family” is defined in federal surveys (such as the U.S. Census Bureau’s American Community Survey [ACS] or Current Population Survey [CPS]) with the way a “family” is defined by most private and public insurance programs, specifically for the purposes of analyzing health insurance coverage.

The SHADAC HIU has been updated over time in response to changes to policy and program eligibility rules. This page provides you with the most up-to-date version of SHADAC’s HIU.

Access the SHADAC HIU code and documentation, HIU issue brief, and accompanying “Defining Families for Studies of Health Insurance Coverage” issue brief below.

SHADAC’s Health Insurance Unit (HIU) Issue Brief and Stata Code

This issue brief describes the SHADAC HIU, its purpose, the most recent updates, and improvements to HIU data inputs made available by IPUMS. The brief aims to support users of the HIU by providing:

  • Context and background;
  • Information on the HIU’s construction;
  • Most recent revisions to the HIU and those revisions’ impact;
  • Details on the essential support from IPUMS;
  • Research applications and considerations;
  • And more. 

You can find the most up-to-date version of the “Health Insurance Unit” issue brief here or by clicking on the image below. 

SHADAC HIU Brief Cover

HIU Stata Code

We also provide the HIU technical documentation of statistical code in STATA to help researchers to employ the SHADAC HIU in their own analysis using ACS microdata downloaded from IPUMS USA. You can access that here.

Defining Families for Studies of Health Insurance Coverage Issue Brief

We also created a second related brief titled, “Defining Family for Studies of Health Insurance Coverage,” which outlines the impacts and considerations of using the SHADAC HIU.

This brief outlines the impacts of using the SHADAC HIU in analysis—specifically, analysis showing how the population distribution of family income changes using three different definitions of family: 

  1. All members in the same household (Census definition)
  2. The definition used by the IPUMS, and
  3. The SHADAC HIU. 

Researchers can use this brief to assess whether the SHADAC HIU is suitable for their analysis and what the potential impacts of its use might be. Find the “Defining Families” brief here or by clicking on the image below.

Brief cover page, titled, "Defining Family for Studies of Health Insurance Coverage"

SHADAC’s HIU: Reach Out with Any Questions

If you have any questions about the SHADAC Health Insurance Unit or need any support or technical assistance regarding its use, don’t hesitate to contact us here or at [email protected].

SHADAC HIU Archive

Below, you can find archived documentation from previous versions of the SHADAC HIU:

"Defining Family for Studies of Health Insurance Coverage" August 2021

"Using SHADAC Health Insurance Unit (HIU) and Federal Poverty Guideline (FPG) Microdata Variables" November 2013

"Defining “Family” for Studies of Health Insurance Coverage" March 2012