Children who are homeless or in foster care change schools more often than their non-mobile peers. The impact of school mobility increases their risk of academic failure (Evans, 1996; Ingersoll, Scamman, & Eckerling, 1989; Mao, 1997, Mehana & Reynolds, 2003; Reynolds & Wolf, 1999). Laws enforcing the right of students to remain in their "original school of enrollment," help increase academic achievement. Two of these laws are the McKinney-Vento Act, a federal law protecting the rights of homeless youth (United States Department of Education, 2004), and AB490, a state law that supports the education of foster youth (Shea, Weinberg, & Zetlin, 2004). Both laws allow students to remain at their original school of enrollment so that they do not have to change schools even if their housing situation changes. Although these laws are in place, homeless and foster youth still tend to change schools more often than their housed peers. This study analyzes indicators of academic achievement including grade point averages, California Standard Test scores, attendance rates, credits earned, and suspensions for seventh through twelfth grade homeless, foster youth, and a non-mobile comparison group in the 2006-2007 and 2007-2008 school years. Address moves and school moves were also analyzed for their impact on academic achievement. The statistical procedures used in this study include correlation coefficients, a canonical correlation, four 3 x 2 repeated measures ANOVAs, and a series of 11 one-way ANOVAs to analyze whether school mobility variables have a statistically significant impact on the academic achievement variables for homeless and foster youth when compared to a third group of non-mobile, or housed students. Almost all procedures yielded statistical differences between the non-mobile comparison group and homeless and foster youth, although there were very few differences found between the homeless and foster students in this study. [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.]