The Individual Placement and Support model of supported employment is one of the most robust interventions available for people with severe mental illness. Supported employment specialists deliver this intervention. There has been little research on what influences specialists' performance in the field. This paper redresses this deficit by documenting characteristics and competencies self-reported by specialists as influential to proficient performance in the field. Twenty-two qualitative interviews were conducted with specialists and their supervisors. Content analysis suggested the importance of eight factors: (1) initiative; (2) outreach; (3) persistence; (4) hardiness; (5) empathy; (6) passion; (7) team orientation (8) professionalism.