The prevalence of adolescents and adults with autism spectrum disorder (ASD) is growing worldwide. There is a lack of services to support adolescents and adults with ASD in different areas including social-communication intervention. To fill these research gaps in the literature, the three studies in this dissertation extended the literature on social-communication interventions for adolescents and adults with ASD. The purpose of these three studies were (1) to conduct a meta-analysis determining effects of social-communication interventions in improving social-communication skills for adolescents and adults with ASD; (2) to analyze the body of literature on using social-communication interventions to adolescents and adults with ASD whether they meet the criteria for What Works Clearinghouse (WWC) basic standard and extended methodological standards; and whether that particular intervention can be considered for evidence-based practices (EBPs) to improve social-communication in adolescents and adults with ASD; (3) to identify how educators could use telepractice intervention as a tool to implement naturalistic strategies for parents with adolescents and adults with autism in their home by conducting a multiple-probe single-case experimental design across participants. The findings of the first study indicated that each social-communication intervention is moderately effective in improving social-communication skills for adolescents and adults with ASD. There are statistically significant differences found for some potential moderators. The findings of the second study found important issues that need to be considered in this field of social-communication interventions for adolescents and adults with ASD in relation to the quality of the single-case experimental design (SCED). In addition, video modeling intervention has been established as an EBP of social-communication intervention for this population. The findings of the third study demonstrated a functional relation between the telepractice parents coaching and parent strategy implementation with a strong effect for all three participants. The findings of these three studies showed several implications for practice and research. Paraprofessionals and researchers should be encouraging adolescents and adults with ASD to use generalization and maintenance for any social-communication activities in their authentic settings and with their natural partners, especially their parents and peers. There are more details on implementation, limitations, and future research were 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.]