The present study used 2011-12 Schools and Staffing Survey (SASS) data to determine the impact of school organizational factors on secondary STEM teacher retention in the post-NCLB era. Researchers utilized teacher and principal instruments from the SASS to measure the retention of grades 9-12 STEM teachers (n = 920). Due to the nested nature of teachers within schools and based on previous retention research, multilevel logistic regression was used to examine the proportion of variance in STEM teacher retention across schools. The study focused on identifying the proportion of variance in STEM teacher retention that was attributable to school differences, as well as the effect of school climate on STEM teacher retention, controlling for teacher and principal characteristics. The study's most important finding was that having a principal who majored in a STEM subject had a positive and significant effect on the retention of secondary STEM teachers.