Customized Employment Research Project (CERP) - Employment outcomes for individuals with the most significant disabilities, including those with intellectual and developmental disabilities (I/DD) and autism, often reveal a troubling trend: Many experience chronic underemployment and unemployment and many others receive services in segregated, facility-based environments. In response, the Rehabilitation Act, as amended by the Workforce Innovation and Opportunity Act (WIOA, 2014), introduced provisions to promote competitive, integrated employment for this population. This amendment expanded the definition of supported employment to include Customized Employment (CE), an individual service model that aligns job opportunities with an individual’s unique strengths, interests, and needs. Goal: The Customized Employment Research Project (CERP) is designed to rigorously evaluate CE's effectiveness as a vocational rehabilitation service. CERP’s primary goal is to utilize randomized controlled trials (RCT) to assess CE’s impact on competitive employment outcomes for job seekers with the most significant disabilities. Objectives: Through this research, we aim to establish CE as an empirically validated, scalable approach that can offer a consistent, transformative employment pathway for individuals with the most significant disabilities. Outcomes: In the first year, we will develop a comprehensive CE replication manual, detailing essential intervention components for each stage of the CE process, followed by intensive training for employment specialists to ensure high-fidelity implementation. In years two and three, consecutive cohorts will be recruited annually across multiple community rehabilitation providers (CRPs), with participants randomly assigned to the intervention group and to the control group each year. The research team will collect data on participant descriptive variables, employment status, employment outcomes, support needs, quality of life, and social validity data. We will analyze employment outcomes using independent sample t-tests and chi-square tests and apply latent growth models (LGM) to examine job satisfaction trends between the two groups. Products: Products include a detailed CE replication manual and validated CE interventions that CRPs can implement consistently and effectively. By providing clear implementation standards and a robust evidence base, CERP will empower providers to deliver CE with fidelity, expanding meaningful employment opportunities and enhancing long-term stability for individuals with significant disabilities. This project will contribute to a sustainable framework that supports meaningful employment outcomes for individuals with the most significant disabilities.