Despite ongoing efforts to increase diversity in science, technology, engineering, mathematics, and medicine (STEM) fields, disparities persist. MYHealth Summer Launch is a virtual, out-of-school STEM outreach program aiming to increase participation of historically marginalized students in health research to develop researcher identity and science motivation. Thirty 9th-12th grade students were enrolled in the 10-day virtual program, where they learned research methods and engaged with academic researchers. We conducted a mixed methods evaluation to assess the feasibility and acceptability of the program, and the influence on researcher identity and science motivation. The evaluation included: 1) pre- and post-surveys measuring researcher identity and science motivation; 2) program participation; and 3) semi-structured interviews exploring program successes and challenges. Thematic analysis findings were integrated with quantitative outcomes (e.g., paired t-tests, linear mixed models) to evaluate program implementation. Students completed an average of 45.75 hours (48.75 hours max) of activities. Mean scores showed a statistically significant increase in researcher identity, intrinsic motivation, and science self-efficacy subscales. Salient themes included: 1) building community in an online environment; 2) exploring what it means to be a researcher. Future program offerings will build on these findings to foster researcher identity and motivation in this population.