The aim of this study was to examine the current proficiency strengths and weaknesses of practicing K-12 non-native WL teachers in the states of Utah and Oklahoma. Data were gathered through a survey and the OPIc diagnostic grid. The results revealed what features of Function, Accuracy, Content, and Text Type were strengths and weaknesses for OPIc ratings Intermediate High, Advanced Low, Advanced Mid, and Advanced High. The self-reported OPI scores compared to the OPIc scores found an encouraging rate of TL maintenance and improvement. The language maintenance activities reported by the participants revealed the frequency with which they engage in those activities.