Participation and Environment Measure Plus (PEM+) is a new electronic health application that facilitates family-centered and participation-focused intervention planning for young children receiving rehabilitation therapies. PEM+ design was informed by caregiver and provider input. It is a web-based intervention planning application that is designed for use by caregivers of young children receiving rehabilitation therapies. Caregivers who complete the Young Children's Participation and Environment Measure (YC-PEM), an electronic patient-reported outcome measure, evaluate their child's participation and then can click on a weblink to begin the PEM+ application, whereby they build on their YC-PEM responses for the purpose of creating a participation-focused care plan to share with their child's rehabilitation team. PEM+ is a five-step recursive process (i.e., the caregiver can repeat the five-step process to create as many care plans for their child as needed), and it offers tiered support to the user during completion (tier 1: frequently asked questions available in the application, tier 2: support provided by email, tier 3: support provided by phone). For the first aim of this study, caregivers completed one iteration of PEM+ to complete user tasks for the purpose of evaluating PEM+ usability. For the second aim of this study, caregivers were instructed to complete the PEM+ over a two-week (14 day) period. This time frame was selected by the research team as it mimics what would be provided in the routine care planning processes of early intervention and early childhood education.