It has been well documented that children's development is enhanced within the context of supportive parent-child relationships (Mortensen & Mastergeorge, 2014). Research also indicates that any daily activity of a child holds the potential for multiple learning opportunities if parents and other caregivers are supported in their capacity to recognize and respond to those opportunities (Dunst et al., 2001; Raab & Dunst, 2006). Thus, in Part C Early Intervention (EI) the development of a triadic relationship (Brown & Woods, 2016), where providers focus not only on the relationship between provider and child but also on the relationships between caregiver and child as well as caregiver and provider, is a priority. While EI service providers use a range of coaching strategies to support families (e.g., caregiver practice with feedback, problem solving, joint interaction, conversation and information sharing, observation; Friedman et al., 2012), this article focuses on one, joint planning. Joint planning is a reciprocal process of collecting and gathering information about the child's skills as well as family routines and strategies. While research in the field has examined the nature and outcomes of coaching related to caregiver-implemented interventions, definitions and descriptions of specific coaching strategies and processes, such as joint planning, remain limited (Lorio et al., 2020). This article seeks to provide such description of joint planning in practice and highlight its particular utility for gathering ongoing assessment data. Indeed, the joint planning process can be strategically leveraged to partner with families in efforts to contribute to comprehensive assessment practices in EI.