Clinically-based Gestalt quantitative research endeavours and Gestalt diagnostic theory are developing to meet current practice context demands for empirical evidence of treatment effectiveness. This paper outlines an ongoing empirical research investigation using clinical data obtained from Gestalt Associates for Psychotherapy (GAP) low-fee clinic investigating the reliability of the Gestalt Mental Status Exam (GMSE) as a measure of clients' contacting resistance styles (N=84). The test-retest reliability of the behavioral indicators used to measure contacting resistances of the GMSE was validated and found reliable (R=.72). The GMSE in conjunction with the Gestalt Inventory of Resistance Loadings (GIRL), another reliable contacting resistance style measurement instrument (R= .83), provide the necessary foundation from which statistical analysis measuring changes in contacting resistances over the course of gestalt treatment. The GMSE provides clinicians in private practice with a reliable instrument for diagnosing, measuring, and recording the progress of their clients as well as providing Gestalt Training Institutes (GTI) with valid and reliable instruments to measure training program effectiveness. GTIs with clinics can employ these instruments for meaningful data collection evaluating Gestalt treatment effectiveness and for quantitative research into evidence based practice.