NHIS Health Insurance Data

Overview

The National Center for Health Statistics conducts the National Health Interview Survey (NHIS) to collect data on a broad range of health topics. NHIS has collected health insurance data since 1959. In the early survey years, NHIS did not collect insurance data annually.

• From 1959 to 1968, NHIS collected data during three years: 1959, fiscal year 1963, and fiscal year 1968
  • The federal government's fiscal year runs from October 1 through September 30
  • Fiscal years are named for the calendar year in which they end
• From 1968 to 1989, NHIS collected data every two years
• Since 1989, NHIS has collected data every year

Data collected

Currently, the data NHIS collects about health insurance include information about the type of coverage, characteristics of coverage, and the reasons for no coverage. Health insurance coverage status is collected for one adult and one child (if present) in each household through the adult and child questionnaires. The adult and child receive a similar set of questions with a few exceptions. The flow and content of the health insurance questions are similar to the questions covered in the 1997–2018 NHIS that asked insurance coverage information for all family or household members.

Updates to health insurance questions

NHIS health insurance questions have changed over time.

Before 1997, health insurance questions were asked on supplements to the basic questionnaire. Beginning in 1997, health insurance was added to the survey's family core questionnaire. Since 1997, the content and flow of the core health insurance section has remained relatively stable.

Shifts in health insurance coverage, insurance programs, and the questionnaires' design can all lead to question additions and changes. For example—

• A Children's Health Insurance Program (CHIP) category was added to the list of coverage types after the Balanced Budget Act of 1997 was passed.
• Questions were added to monitor changes after the Affordable Care Act of 2010 was passed.
• New questions in 2014 collected information about coverage through the Federal Health Insurance Marketplace and state-based exchanges.
• In 2018, the survey added a question for U.S. veterans. The question for anyone who has served in the armed forces asks about their use of Veteran's Administration healthcare services.

Questionnaire content

The core content for the NHIS adult and child questionnaires covers a range of topics.

• Type of healthcare coverage
• Features of Medicare, Medicaid, CHIP, and other government programs
• Enrollment in specific Medicare parts and Medicare Advantage
• Characteristics of private insurance plans
• Military-based coverage, including TRICARE, VA, or CHAMP-VA
• Periods of time without health insurance with reasons for the gap in coverage

Health insurance statistics

The NHIS Early Release program provides preliminary estimates in the November/December, February/March, and May/June Health Insurance Coverage Early Release tables and reports.

Final annual national estimates are published in the National Health Statistics Reports (2019–2022), standalone tables (2023), and Long-term Trends in Health Insurance Coverage (1968–2023).

For earlier health insurance estimates and reports about health insurance coverage trends, design, and methodology, visit the CDC Archive.