School counselors actively pursue postgraduate professional development to stay current with the best social-emotional learning (SEL) implementation practices. Professional development can vary depending on the school district. Despite these discrepancies, school counselors recognize how intentional professional development can further strengthen their ability to believe in how well they implement SEL. This study sought to answer the research question, "What are school counselors' experiences with self-efficacy as they implement social-emotional learning for students?" Utilizing a generic qualitative design, the study involved ten school counselors in the United States with a minimum of six months of active employment in K-12 settings actively implementing social-emotional learning (SEL). Semistructured interviews, guided by criterion sampling, explored participants' self-efficacy experiences and perceptions of intentional professional development. Thematic analysis through flexible pattern matching identified three emerging patterns influencing school counselors' self-efficacy: performance experience and access to resources, social persuasion and feeling valued by collaboration, and physiological experience and strategies for managing uncontrolled situations. The findings highlight the role of intentional professional development in fortifying the counselors' belief in their ability to implement SEL effectively. This research contributes to understanding how purposeful professional development activities can enhance school counselors' professional identity and self-efficacy in SEL implementation. Further exploration is suggested to delve into the content of intentional professional development, its potential correlation with increased self-efficacy, and the impact of deliberate collaboration on school counselors' effectiveness in supporting students' social-emotional well-being. [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.]