Federal legislation has mandated students with and without disabilities be prepared for college and careers (ESSA, 2015; IDEA, 2004). Students with high-incidence disabilities experience less success than their peers without disabilities (Newman et al., 2011). Initially, college and career readiness efforts lacked a focus on students with disabilities (e.g., Conley 2007, 2008), but recent efforts have increased the focus on students with disabilities (e.g., Morningstar et al., 2017). The predictors of postschool success appear to be a viable option to bridge both efforts. Students with high-incidence disabilities spend at least part of their day in general education classes (NCES, 2017b), but general education teachers report wanting additional information to prepare students with high-incidence disabilities for college and careers (Kwiatek, 2017). General educators identified the predictors of postschool success as relevant, important, and feasible for implementation (Kwiatek et al., 2021). Coupling the alignment between secondary transition and college and career readiness, the predictors of postschool success appear to be an ideal option to provide general educators with professional development to prepare students with high-incidence disabilities for college and careers. The purpose of this dissertation was to examine the effects of an asynchronous online intervention (i.e., General Educators Now Embedding Research [for] Adult Life in Educational Design [GENERAL ED]) on general education teachers' knowledge of research-based and evidence-based, in-school predictors of postschool success. Results of this intervention indicated a functional relation between the asynchronous online intervention and increased knowledge of three predictors of postschool success. Effect sizes were large for increased knowledge of the predictors of postschool success. Additional measures included application; confidence; generalization; and social validity (i.e., feasibility evaluation, intervention rating scale). Finally, limitations, suggestions for future research, and implications for practice will be discussed. [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.]