In 2019, the family treatment court (FTC) best practice standards (the Standards) were published to clarify attributes of FTC programs associated with superior child, parent, and family outcomes. The Standards cover the breadth of FTC operations including program structure and leadership, substance use treatment and complementary services, and behavioral responses to participants. This study aimed to develop an instrument (the Model Standards Implementation Scale; "MSIS") that stakeholders can use to assess implementation of the Standards by individual FTCs. The MSIS balances usability with scientific validity. Interrater reliability (IRR), internal consistency, and several types of validity were assessed. Results indicated moderate to strong IRR, high internal consistency, mixed known groups validity depending on Standard, and high convergent and divergent validity. Initial findings suggest good validity and usability of the MSIS for evaluating FTC Standards' implementation. Notably, the process of using the tool functioned to educate FTC team members on the Standards. Although implementation of the MSIS is a resource-intensive process, the opportunity to receive constructive feedback proved to be an effective incentive for initial and subsequent participation in the evaluation among FTCs. Future research is needed to examine predictive validity, including association between Standards' implementation and family outcomes in FTCs.
