OBJECTIVES/GOALS: Our objective was to evaluate the FLEX Leadership Development Program for School of Medicine Women Faculty affiliated with 4 independent hospital systems throughout Northern Ohio to determine whether women faculty develop leader self and means efficacy. We also examined whether self-efficacy is sustained over time following program completion. METHODS/STUDY POPULATION: We did a prospective multiple cohort study to determine whether FLEX Program graduates develop and sustain leader self and means efficacy as measured by the Leader Efficacy Questionnaire (LEQ) (Hannah & Avolio, 2012). The LEQ assesses both leader confidence in their capabilities (self-efficacy) and the availability of sufficient external resources (means efficacy) to achieve their goals. We surveyed participants from 5 FLEX cohorts (2017-2021) using a pre-, post-, and 1-year follow-up LEQ, which allowed each participant to act as their own control subject, pre-test, and experimental post-test. The follow-up tested whether the change from pre- to post-test was sustained over time. The comparison group was non-participant women faculty from the same institutions over a similar 2-year period. RESULTS/ANTICIPATED RESULTS: Diverse FLEX graduates from 5 different cohorts showed highly significant increases in pre- to post-program leader self-efficacy which were sustained up to one year after program completion. Overall leader efficacy as well as its three component sub-constructs (action-, means- and self-regulation- efficacy) all significantly increased equally, suggesting both that the FLEX program had robust effects on its participants, and all aspects of leader efficacy improved. We observed a mildly significant decrease at 1-year follow-up in the overall LEQ, which appeared to be driven entirely by the leader means efficacy. The large comparison group of women faculty did not show any significant changes in leader self-efficacy over a comparable 2-year period. DISCUSSION/SIGNIFICANCE: FLEX confers sustainable gains in leader self-efficacy. Post-program self-efficacy decreases are driven by the leader means efficacy which measures how work environments affect their leadership. This suggests that institutions must take responsibility for making structural changes to improve the working environment for women leaders.