Factors Influencing Implementation of Primary Service Provider Teaming Practice in Early Intervention

This mixed-methods study examined real-world implementation of the primary service provider (PSP) teaming model in early intervention (EI) programs and identified individual- and program-level factors influencing implementation. Guided by implementation science frameworks, quantitative and qualitative data were collected from 30 practitioners across 11 EI programs using a fidelity checklist, scales, questionnaires, and interviews. Practitioners demonstrated moderate to high implementation fidelity, supported by statewide mandates, systematic training, and technical assistance. Leadership, cross-disciplinary knowledge and skills, ongoing training and colleague coaching, self-efficacy, and attitudinal openness among providers, particularly those with medical backgrounds, emerged as the most influential facilitators, whereas workforce shortages and limited funding constrained team formation and sustainability. Findings suggest that individual-level factors are interrelated with program-level conditions and can be strengthened through organizational supports. They highlight multilevel, context-responsive strategies that engage families and health care providers and address program-specific challenges to strengthen PSP implementation in EI programs.