Educational leaders agree that public education in the United States is in crisis due to the shortage of high-quality teachers in public schools and the subsequent strain those shortages place on the teacher labor market. Because much of the U.S. teacher workforce is comprised of members of the millennial generation, this research examined why millennial teachers are exiting the profession at unprecedented rates. The attrition of millennial teachers from high-poverty schools has been largely overlooked in the extensive literature on teacher retention. This qualitative case study investigated the personal, school, and external correlates that influence millennial teacher attrition. The main research question was: What factors influenced the decisions of millennial teachers to leave their positions and/or the teaching profession after serving in high-poverty schools? The researcher collected and analyzed pre-existing data from open-ended surveys and interview transcripts. Seven themes and 19 sub-themes emerged from the data that add to the body of research on factors influencing millennial teacher attrition. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]