Measurement-based care, an evidence-based practice endorsed by the American Psychological Association, is underpinned by routine assessment supporting a data-driven approach to clinical decision making. Nonetheless, there is a need for brief, nonproprietary measures assessing non-symptom-based outcomes. The present study examined the psychometric properties of the Therapy Progress Scale (TPS), a four-item measure assessing clients' perceived treatment progress in multiple life functioning domains. The sample included 36,420 clients (66% female, 55.5% White, 31.5% Racial/Ethnic Minority) receiving outpatient psychotherapy from a practice-research group of private practitioners. The TPS demonstrated a one-factor solution (X[superscript 2] (2) = 362.08, RMSEA = 0.076, CFI = 0.999, TLI = 0.996) with high reliability estimate (coefficient [alpha] = 0.87). Additionally, the factor structure was consistent across client gender and race/ethnicity. There were moderate negative correlations with symptom-based measures (i.e. PHQ-9 and GAD-7). Test-retest correlation was also strong. Implications for research and practice are provided.