Purpose: The goal of this study was to investigate the initial feasibility of the Communication Matrix Professional Development Program (CMPDP), an online program created to help educational professionals teaching students with complex communication needs. Method: A one-group pretest-posttest design was employed with 102 educational professionals and their students with complex communication needs. Students (M[subscript age] = 12.5 years, SD = 4.8 years) had severe expressive communication impairments characterized by an expressive vocabulary of < 10 words. The online CMPDP included webinars, coursework, and engagement with an online community of practice. We examined the students' expressive communication skills measured by the Communication Matrix Assessment and Individualized Education Program (IEP) goal quality measured by the Design to Learn IEP Goal Development Guide before and after their teachers and speech-language pathologists participated in the intervention. Results: Students showed small but significant increases on the Communication Matrix Assessment. The average increase in scores was 10.6, z = 5.37, 95% confidence interval (CI; [6.65, 14.54]), Glass's delta = 0.37. The mean gain in scores for IEP quality was not significant (0.82, z = 2.43, 95% CI [0.14, 1.49], Glass's delta = 0.28). Conclusions: Results demonstrate the initial feasibility of the CMPDP for educational professionals and their students with complex communication needs. Findings must be interpreted cautiously as the study design has methodological limitations including lack of a control condition and a potential for correlated measurement error and demand characteristics.