Interprofessional education (IPE) is important to prepare graduate students for collaborative practice. This mixed methods study sought to evaluate a full-semester, asynchronous online IPE course for graduate students. Thirty-one graduate social work, nursing, public health, and health administration students participated. Interprofessional socialization and collaborative competencies were measured at three points in the semester. There were statistically significant improvements in self-reported socialization and competencies. Qualitative analysis revealed participants experienced new perspectives, developed appreciation of interprofessional collaboration, practiced communication and teamwork skills, and used course lessons in clinical practice. Study findings indicate that online IPE can help improve graduate students' interprofessional socialization and collaborative competencies. Further, students indicated they applied course lessons to their school and work clinical practice sites.