PROJECT SUMMARY Effective mentorship is a critical component for academic and career development, particularly for trainees underrepresented (UR) in the biomedical workforce. The Mount Sinai Post-Baccalaureate Research Education Program (PREP) has a long history of successfully training UR scholars for biomedical graduate programs (e.g., PhD or Md-PhD). This important work requires dedicated time and effort to adequately support the unique needs of UR trainees, who may need more support and attention. Substantial data reveals that racial and other biases persist in biomedical education. For example, a 2022 Pew Research study found that nearly half of all Black workers in STEM (48%) experienced mistreatment in their STEM education, with over one-third reporting that someone treated them as if they could not understand scientific concepts (34%) or made them feel as though they did not belong in STEM (34%). There is growing recognition that higher rates of attrition among racial/ethnic graduate students will hamper efforts to diversify our biomedical workforce – efforts that are critical to our ability to conduct high-level science and deliver optimal health care. Cultivating a culture of inclusivity and psychological safety within the research training environment are important components to developing a diverse biomedical workforce. Thus, the goal of the proposed supplement is to enhance the Mount Sinai PREP in two ways: 1) well- being and psychosocial support for trainees and 2) additional anti-racism and -bias training for faculty mentors. The proposed activities will provide unmet psychosocial support for our PREP trainees by offering opportunities to discuss their mental and emotional well-being as URM trainees, and mentor training specific to mitigating racism and racial stereotypes for program faculty. We will accomplish these goals by partnering with faculty from the Mount Sinai Center for Scientific Diversity (CSD) who will lead monthly group discussions with PREP trainees on relevant well-being topics including scientific identity, sense of belonging, imposter phenomenon and resilience. Additionally, PREP faculty mentors will participate in a 5-week mentor training workshop (1.5-hour sessions) lead by CSD faculty. The workshop curriculum will teach mentors practical strategies for mitigating racism and racial stereotypes in their research labs as well as within their mentor-mentee relationships. Outcomes will be evaluated at the individual level (i.e., PREP trainees and faculty mentors) and program level (e.g., number of participants) for each component (e.g., mentor training and well-being discussion sessions). Our long-term goal is to impact the research experiences of our PREP trainees and the overall effectiveness of our PREP program. If proven successful, we will obtain institutional support to sustain the proposed activities in both Mount PREP and across all research training programs within the institution.