The Early Childhood Language Development Institute (ECLDI) aims to support the success of young dual language learners (DLL's) currently enrolled in State-funded early learning programs in San Mateo County. Established in 2003 and administered by San Mateo County Office of Education (SMCOE), ECLDI provides a comprehensive professional development model for early learning professionals and leaders, and families of DLLs. This model works to (1) foster reciprocal, authentic, school-family partnerships; as well as (2) transform the culture, practices, and policies in early learning settings to support classrooms and learning environments that are responsive to the needs and assets of DLLs and their families. In 2015, ECLDI partnered with the John W. Gardner Center for Youth and their Communities at Stanford University (Gardner Center) to assess its current programming and support future development. In this report, the authors provide background on the relevant national research base as well as relevant local context, describe the current study and methods, and share implementation findings. Specifically, they describe what they learned about program participants and service delivery, promising emerging patterns in teacher and parent practice, and conditions that facilitate or hinder ECLDI program implementation. [Appendix is not included in the ERIC version of the report.]