The National Health Interview Survey (NHIS) has monitored the health of the nation since 1957 and collects data on a broad range of health topics through personal household interviews. NHIS has collected health insurance data periodically since 1959 and annually since 1989. The NHIS health insurance questions have changed and expanded over time to reflect changes in health insurance coverage as well as questionnaire design. Since 1997, the content and flow of the health insurance section has remained relatively stable, incorporating new programs where necessary. For example, new questions added in 2014 obtain information about whether coverage was obtained through the Federal Health Insurance Marketplace and state-based exchanges.
The NHIS allows for both point-in-time uninsured estimates as well as full-year and part-year uninsured estimates. Three estimates of lack of health insurance coverage are published for each calendar quarter: (a) uninsured at the time of interview, (b) uninsured at least part of the year prior to interview (which includes persons uninsured for more than a year), and (c) uninsured for more than a year at the time of interview. In addition, NHIS provides estimates of both public and private coverage as well as enrollment in high-deductible health plans and exchange-based coverage. The NHIS may be used to monitor changes in health insurance coverage throughout the year as the survey is fielded continuously throughout the year.
To see the latest quarterly numbers on health insurance coverage through January-March 2016, check out: Health Insurance Coverage: Estimates from the National Health Interview Survey, January-March 2016, released on September 7, 2016.