BACKGROUND: A collaborative initiative was undertaken to restructure diagnostic and support services for developmental disabilities (DD) in young children in the province of Québec. Representatives from multiple stakeholder groups, including researchers, parents, and clinicians, shared insights based on their experiences with diagnostic evaluation services. AIMS: The present study documented stakeholders' experiences with existing DD services, with a focus on identifying barriers, facilitators, and gathering actionable recommendations for the creation of a new model for diagnostic evaluation. METHOD: Twenty-nine stakeholders shared their experiences in focus group and individual interviews. Their discourse was analyzed according to the quality determinants of the ETAP framework (Rivard et al., 2020) and categorized as barriers, facilitators, or recommendations. RESULTS: Stakeholders described several barriers related to continuity and accessibility within the current system but also discussed some facilitators that promoted, e.g., the accessibility and validity of services. They made several recommendations to improve upon or clarify existing elements and identified what could be added. CONCLUSIONS: These testimonials from stakeholders emphasize the need to conceptualize the DD service trajectory as a whole. This will require improving upon information-sharing and collaboration practices, formalizing procedures, and adding case navigation and parent support modalities.