This study examined the professional identity development of counselors-in-training (CITs), considering the influence of personal and program factors. The data were collected from 198 master's-level CITs enrolled in CACREP-accredited programs. Results of hierarchical multiple regression analyses indicated that CITs' personal traits, such as gender identity, year in their program, and perceived stress, significantly predicted their professional identity dimensions. We also identified that program factors, including clinical and course experiences and multicultural program environment, significantly predicted CITs' professional identity dimensions beyond the personal traits. Implications and recommendations for counseling research and counselor education are provided.