Retention is the decision to have a student repeat a grade as opposed to being promoted to the next school year with same-age peers. Research suggests that retention in the early elementary grades may not support better student outcomes and may, in fact, be harmful to a child's future academic and social success. Even among lower-performing students, those who were retained were more likely to have lower performance on standardized tests, to dislike school, and to drop out of school compared to peers who were not retained. In addition, retention obligates state and local government to an additional year of funding for each child who repeats a grade, increasing overall costs for educational systems. The purpose of this issue brief is to examine differences in retention rates between students who received First Class Pre-K and those who did not, among low income students as indicated by receipt of free or reduced price lunch. (author abstract)