A family-capacity building approach to coaching, where providers support caregivers to embed identified strategies into daily routines and activities, is commonly embraced in Part C Early Intervention (EI). EI providers use several coaching strategies within this approach, yet few studies have reported process features, and coaching strategies are not well defined in the literature. We partnered in this Participatory Action Research (PAR) with current EI providers engaged in a year-long self-study process to provide an empirical account of one coaching strategy, joint planning, and related documentation. Our results indicate both providers and caregivers view documentation of joint planning as beneficial, highlight supports and challenges, and suggest that joint planning documentation holds significant promise for improving practice, data-based decision making, and progress monitoring of child and family outcomes including changes in caregiver capacity. (author abstract)