In recent years, there has been an increase in the research on reflective supervision, including the development of tools designed to measure reflective practice in the context of reflective supervision. The Reflective Supervision Self-Efficacy Scale for Supervisees (RSSESS) is a self-report measure that has been used in previous evaluations and is designed to assess perceived reflective practice self-efficacy for Infant Mental Health-Home Visiting (IMH-HV) therapists. Properties of the RSSESS including factor structure and reliability are explored in a first study that lays the foundation for the use of the RSSESS in an IMH-HV evaluation in the State of Michigan. IMH-HV therapists completed the RSSESS at 4 time points over a 12-month period and also completed a Clinician Profile Form that included questions about their IMH background and their work experience, including job satisfaction and burnout. Results indicated that the RSSESS is a reliable tool to measure change in reflective practice skills. IMH-HV therapists demonstrated growth in their use of reflective practice skills with families and their observational skills over the 12-month period. In addition, results indicated correlations between reflective supervision self-efficacy and job satisfaction as well as burnout.