Identity concealment thwarts psychological needs of authenticity and belonging, both of which are important for mental health and relationship building. Through the lens of minority stress theory and relational-cultural theory, the present study examined whether identity concealment in the workplace by psychology trainees is indirectly associated with greater burnout and poorer therapeutic relationship quality. To test this hypothesis, a parallel mediation analysis was conducted on data from 335 clinical and counseling psychology doctoral trainees with concealable stigmatized identities using Hayes's (2018) PROCESS macro. As expected, identity concealment at a practicum or internship site was negatively associated with authenticity and belonging, both of which were negatively associated with burnout and positively associated with therapeutic relationship quality. Furthermore, identity concealment was associated with lower therapeutic relationship quality and greater burnout indirectly through lower authenticity and lower belonging. Findings suggest trainees who engage in more identity concealment at their clinical training sites may be at increased risk for burnout and poorer relationships with clients due to limited opportunities for authenticity and belonging. Future research is encouraged to longitudinally examine the impact of identity concealment on professional burnout and relationships, as well as potential protective factors. Such knowledge can support the development of interventions and policies that foster safer, more welcoming work environments for trainees with concealable stigmatized identities. Clinical Impact Statement Question: Does identity concealment present a possible barrier to the psychotherapy process among clinical and counseling psychology doctoral students with concealable stigmatized identities, and why? Findings: Psychology trainees with concealable stigmatized identities who engaged in more identity concealment within their practicum or internship reported higher rates of burnout and poorer therapeutic relationship quality, possibly as a function of lower levels of authenticity and belonging. Meaning: Psychology trainees need to be aware of the potential risks of concealing a stigmatized identity within their clinical training sites-as well as their own human need for authenticity and belonging-for the sake of their well-being and the well-being of their clients. Next Steps: These findings underscore the need for the development of structural changes (e.g., the implementation of culturally responsive policies, discussions, and trainings) that reduce identity-based stigma and the likelihood of identity concealment within graduate training programs in clinical and counseling psychology.