Capacity-building family-centered practices are a fundamental component of Early Intervention (EI) service delivery, yet their adoption by EI practitioners remains inconsistent. Lack of sufficient practitioner training and overly broad recommended practices for practitioners are cited as potential barriers to their implementation. The triadic strategies presented in the (Parents Interacting With Infants) PIWI framework outline a set of practitioner behaviors that aim to support caregiver capacity through the facilitation of positive caregiver-child interactions in the context of developmental-enhancing activities. However, little is known about the effects of the triadic strategies on caregiver-child interactions when delivered via teleintervention. Also, professional development opportunities need to be explored for improving practitioners' use of these strategies. This mixed methods study used a single-case research design to examine the efficacy of a virtual training and coaching intervention in increasing practitioners' use of triadic strategies with caregivers and their young children during teleintervention services. Additionally, we used qualitative interviews to understand the experiences and perspectives of EI practitioners and families regarding a triadic, family-centered approach to virtual service delivery. Results suggest modest, but consistent, increases in practitioner use of strategies with training and coaching. Participants shared positive experiences with the intervention and implementation of strategies, along with factors influencing strategy use. Implications for practice and research are discussed. This study contributes to the field's understanding of how virtual training and coaching opportunities might support practitioner use of capacity-building, family-centered practices needed to promote positive family outcomes in EI. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]