The 2002, 2007, and 2012 complementary medicine questionnaires fielded on the National Health Interview Survey provide the most comprehensive data on complementary medicine available for the United States. They filled the void for large-scale, nationally representative, publicly available datasets on the out-of-pocket costs, prevalence, and reasons for use of complementary medicine in the U.S. Despite their wide use, this is the first article describing the multi-faceted and largely qualitative processes undertaken to develop the surveys. We hope this in-depth description enables policy makers and researchers to better judge the content validity and utility of the questionnaires and their resultant publications.