The 2015 Parallel Survey was conducted to fulfill budgetary requirements for the 2015 fiscal year. According to Public Law 113-235 Dec. 16, 2014, the Census Bureau was to "collect data for the Annual Social and Economic Supplement to the Current Population Survey using the same health insurance questions included in previous years, in addition to the revised questions implemented in the Current Population Survey beginning in February 2014."

The Parallel Survey, which was fielded in March and April 2015, used the same traditional health insurance and income questions that were used in the 2013 CPS ASEC and previous years. Efforts were made to ensure that the Parallel survey resembled the traditional CPS ASEC, including using the same interviewers, a production setting, and the full CPS basic interview that precedes the March supplement questions. In addition, the Parallel survey was processed by the same system that processes the CPS ASEC.

According to the 2015 Parallel Survey, the uninsured rate in 2014 was 10.6 percent - not statistically different from the uninsured rate of 10.4 percent from the 2015 CPS ASEC.

Note: There was a different distribution of survey mode between the two surveys, where more of the interviews from the 2015 Parallel Survey were conducted in telephone centers than interviews for the 2015 CPS ASEC (compared with in-person interviews). Because survey mode is also related to the uninsured rate, data users should exercise caution when comparing the 2015 Parallel Survey estimates to the 2015 CPS ASEC estimates without making further adjustments.