["Journal of Employment Counseling, EarlyView. ", "\nABSTRACT\nThis study explores protean and boundaryless career profiles among parallel career track (PCT) holders, who are professionals who voluntarily maintain more than one career role simultaneously, and examines their relationship with sustainable career outcomes. PCT holders were identified to have three established profiles: trapped/lost; organization person; and Protean career architect, alongside two new ones, Ethereal and Spare. Notably, Ethereal and Spare represent profile configurations not previously identified in the empirical literature on protean and boundaryless careers. Pairwise comparisons revealed significant differences in sustainable career outcomes. This study enhances career development practice by identifying distinct PCT profiles and their implications for career sustainability, offering insights for practitioners, career counselors, and organizations. The study shows how PCT profiles can inform counseling interventions aimed at enhancing career sustainability.\n"]