The Mindfulness-Based Interventions: Teaching Assessment Criteria (MBI:TAC) is a tool for supporting good practice in mindfulness-based teaching, training supervision and research contexts. It has been taken up in practice in teacher training organizations worldwide. The MBI:TAC sits within the wider consideration within research contexts of building methodological rigor by developing robust systems for ensuring intervention integrity. Research on the tool is at an early stage and needs development. The process of implementation needs careful attention to ensure reliability and good practice. Future research is needed on the tool’s reliability, validity and sensitivity to change, and on the relationships between mindfulness-based teaching, participant outcomes and key contextual factors, including the influence of participant population, culture and context.