Previous research demonstrates that there is an association between effective teaching and teachers' positive psychological functioning at work. The current study explores the factor structure of the Teacher Subjective Wellbeing Questionnaire (TSWQ), which is a brief measure of two key dimensions of teachers' positive psychological functioning: school connectedness and teaching efficacy. Confirmatory factor analysis was conducted on TSWQ responses from a sample of 1,883 teachers across eight states, with results suggesting that the TSWQ is a structurally valid measure of its two purported teacher well-being constructs. Furthermore, measurement invariance analyses reveal that the factor structure of the TSWQ stays consistent across elementary, middle, and high school teachers. Taken together, findings from the current study further support the technical adequacy and, by extension, the applied use of the TSWQ in schools to screen for intervention, measure outcomes, and monitor progress.