To address chronically low rates of academic achievement among students with disabilities, as well as the high rates of burnout and attrition among special educators, new models for educator professional learning are critically needed. The EXPERT professional learning (EXPERT-PL) model aims to develop early career special educator expertise in DBI while also supporting well-being through social-emotional learning (SEL) for educators. This mixed methods proof-of-concept study of EXPERT-PL sought to address four overarching aims: (1) to measure changes in early career special educators' DBI knowledge and skill, perceived stress, self-efficacy, and job satisfaction after participating in EXPERT-PL; (2) to describe special educators' job satisfaction during participation in online professional learning; (3) to merge qualitative and quantitative findings to achieve a more comprehensive understanding of the impact of professional learning on early career special educators' DBI knowledge and skill, perceived stress, self-efficacy, and job satisfaction; and (4) to assess feasibility of EXPERT-PL as a viable professional learning model. The final study sample included nine participants from four different U.S. states and one Canadian province. The sample was 89% female and 11% male, ranging in age from 20 to 40 years. Teaching experience ranged from less than one year to two years as the sample included both preservice and in-service special educators. Paired samples t-tests of pretest and posttest survey responses demonstrated a significant effect on graph interpretation skills (d = 1.11) and self-efficacy for applying data to instruction (d = 0.89), with participants who attended 100% of EXPERT-PL meetings showing the greatest growth in these two areas. Participation in EXPERT-PL did not appear to impact perceived stress or job satisfaction in the short term, though participant ratings indicated high levels of satisfaction with the program. As a proof-of-concept, this study demonstrates the promise of EXPERT-PL for supporting early career special educators' DBI knowledge and skill, as well as their self-efficacy for applying data to instruction, though it is unclear whether the inclusion of an SEL component was beneficial. To improve student achievement, educators must have ongoing access to high quality professional learning opportunities that develop their expertise in relevant areas (e.g., content, pedagogy, data use) and that they find acceptable or not overly burdensome. The present study of EXPERT-PL demonstrates its potential for future exploration of online learning models to increase special educators' skill and self-efficacy. [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.]