Part C Early Intervention (EI) systems are an entry point to services for autistic toddlers and can be leveraged to facilitate access to autism evidence-based practices (EBPs). However, EI systems are complex and limited research has examined how an EI system’s infrastructure (i.e. system-level factors) impacts the adoption and implementation of EBPs. To address this gap, 36 EI providers and 9 EI administrators completed a semi-structured interview or focus group about factors impacting the implementation of autism EBPs. Qualitative analysis included a combination of grounded theory and causative coding. Analyses were refined by input from providers, administrators, and family stakeholders in the form of round tables and presentations at the state’s interagency coordinating council. Primary themes centered on: (1) the costs associated with independent contracting structures; (2) operational demands; (3) workforce stability; (4) communication consistency; and (5) implementation supports for EBP implementation. Causative coding helped to demonstrate the perceived relationships between these factors and underscored the important role of incentivization structures, collaboration opportunities, and championing in supporting the use of EBPs within a system that primarily uses independent contracting structures. The current study extends previous research by demonstrating how several system-level factors are perceived to play a role in the adoption and implementation of EBPs by independently contracted EI providers. These findings underscore the need for implementation strategies, such as incentivization strategies and social network building, to increase providers’ implementation of autism EBPs within EI systems.© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.