Many organizations utilize formal mentoring as a means of human resource development. Positive mentoring experiences can lead to positive outcomes for the mentor, mentee, and organization; however, negative mentoring experiences can have the opposite effect. The purpose of this qualitative descriptive case study was to examine how mentees describe perceived impactful interactions relating to career and psychosocial functions in mentor relationships within a formal mentor program for instructional designers in the United States. The theoretical framework guiding this study was Kram's mentor theory indicating mentoring serves both career and psychosocial functions. The sample consisted of instructional designer mentees who had completed a formal mentoring program in the United States within the past three years. Data collection included personal journals, semi-structured interviews, and two focus groups. Braun and Clarke's six-phase thematic analysis was used in data analysis, and the data was triangulated to check for convergence. The four themes identified through the analysis were create a nurturing environment, develop hard skills, develop soft skills, and help career advancement. The results of this study may inform mentoring programs for instructional designers by identifying high-impact interactions between mentors and mentees. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]