In response to numerous requests for information regarding the status of K–12 STEM education in the United States, Horizon Research, Inc. conducted the 2018 National Survey of Science and Mathematics Education (NSSME+). The plus symbol reflects the study’s added emphasis on computer science and engineering, two disciplines that are increasingly prominent in discussions about K–12 STEM education and college and career readiness. The study was the sixth in a series of surveys dating back to a 1977 study commissioned by the National Science Foundation. The 2018 NSSME+ assessed changes over time and provided data on essential elements of the STEM education system to inform education policy and practice.