In recent years, attention has been given to the academic impact of afterschool programs. Some schools collaborate with afterschool programs in an attempt to align the learning that occurs during the school day with the learning that occurs during afterschool hours, and thus maximize the potential to positively impact student academic achievement. However, very little research has sought to estimate the associations of alignment practices with academic achievement. This dissertation proposes a conceptual framework of alignment between school and afterschool programs that incorporates measuring academic resources, communication and a sense of partnership. It reviews the research on such practices, and synthesizes the work within the proposed framework. In the statistical study, survey data were collected from principals and afterschool staff at 78 schools across eleven school districts in Southern California. Respondents reported their perceptions of alignment between the school administrators and the afterschool program on three scales: academic resources, communication, and partnership. Highly aligned schools were defined as those in which both the principal and the afterschool staff reported high levels of alignment on all three scales. Misaligned schools were defined by an absolute difference in scores between principals and afterschool staff. Both measures were associated with relative changes in the average academic achievement of over 8,000 students who were included in the analysis sample. Results indicate a positive association between high alignment between principals and afterschool staff on academic achievement of students in both English Language Arts and Math, when compared with lower aligned sites. Significant negative associations were detected in Math when sites were misaligned. Findings document the need for more research in this under-studied area. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]