The Reflective Interaction Observation Scale (RIOS™) was developed as a research tool to identify the extent to which a supervisory session demonstrates a reflective process grounded in infant and early childhood mental health (IECMH) principles and practice. It is aligned with the competencies of the Endorsement for Culturally Sensitive, Relationship-Focused Practice Promoting Infant Mental Health® supported by the Alliance for the Advancement of Infant Mental Health, and it has shown initial evidence of validity and reliability (Meuwissen & Watson, 2021). Specifically, the RIOS is applicable to IECMH-informed reflective supervision/consultation (RS/C) that is based in developmental and attachment theory, trauma-informed practice, and attention to diversity, equity, and inclusion (DEI). It is supported by the rapidly growing body of research exploring interpersonal neuroscience (Bowlby, 1969/1982; Siegel, 2012; Siegel & Shamoon-Shahnok, 2010; Sroufe, 1996; Sroufe et al., 2005). The article is excerpted and adapted from the "RIOS™ Guide for Reflective Supervision and Consultation in the Infant and Early Childhood Field" (ZERO TO THREE, 2022). [The article is written with Maren Harris.]