Objectives. To explore research mentoring experiences and perceived mentoring needs of aging and disability researchers at different career stages. Design. Focus group and individual interviews with rehabilitation researchers at various career stages based in hospitals, universities, and hospital-based research institutes in Ontario, Canada. Results. The overall theme was mentoring for transition. Participants across career stages referred to helpful mentoring experiences as those that assisted them to move from their previous stage into the present stage or from the present stage into their next career progression. Unhelpful mentoring experiences were characterized by mentor actions that were potentially detrimental to transition. Subsumed under this theme were three categories. The first, "hidden information" referred to practical information that was difficult to access. The second "delicate issues" referred to helping the participant work through issues related to sensitive matters, the discussion of which could put the participants or their colleagues in a vulnerable position. The third category was "special challenges of clinician-researchers". Conclusions. Helpful mentoring for rehabilitation researchers working on concerns related to aging and disability appears to be characterized by interaction with more experienced individuals who aid the researcher work through issues related to career transition.