The current study examines the morphological knowledge (MK) and self-reported MK self-efficacy of speech-language pathologists (SLPs) and educators in an effort to inform professional development and preservice training related to MK and skills in implementing morphological instruction. This sample of 850 U.S. participants consisted of SLPs (n = 406), English language arts teachers (n = 178), special education teachers (n = 201), and reading specialists (n = 65). A survey elicited professional experience, self-efficacy related to the application of MK, and a MK measure. Correlations and analyses of variance (ANOVAs) between the groups that differed by disciplinary backgrounds were conducted to assess differences in MK and MK self-efficacy. The results yielded two key findings: (a) MK differs by profession, with SLPs performing with higher accuracy in morpheme counting and nonword derivation tasks and (b) MK self-efficacy differs by profession with reading specialists rating themselves significantly more confident than all other professions.