The purpose of this quantitative causal-comparative study was to evaluate the long-term effects of Florida's Third-Grade Retention policy on low performing students' subsequent academic performance as measured by FCAT reading scores. The study included a random stratified sample of 1500 retained third graders for failure to meet Florida's retention policy and 1500 promoted third graders who also failed to meet the benchmark, but were promoted to fourth grade through a "good cause exemption." The cohorts' FCAT reading scores were analyzed during the 4th, 6th, and 10th grades. T-test and chi square statistical analyses indicated that the retained third graders' post FCAT reading scores were significantly statistically higher than those of the promoted cohort the year after intervention and at 6th grade. However, by 10th grade the promoted cohort's scores were slightly higher than those of the retained students and there was no significant statistical difference between the cohorts' scores. The findings also indicated no significant statistical difference between the retained cohort's dropout rate and that of the promoted cohort. Consistent with most retention research, Black students experienced a higher incidence of dropout than that of other racial and ethnic groups. The retained cohort's 50% and 43% for the promoted cohort exceeded the 49.3% of Black students retained and 35.2% of Black "good cause exemptions." Similarly, consistent to their representation in the sample, males represented the largest subgroup of dropout students. Additional research is needed to better understand the short and long term impact of test based retention policies on retained students' subsequent outcomes given the consistent data that indicate retention gains fade out over time and that retained students have a higher propensity to dropout than promoted low performing students. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]