This summary is based on findings from the evaluation of National Girls Collaborative Project (NGCP) from 2011 to 2018. The report presents evidence on how NGCP has increased collaboration, sharing of resources, and knowledge and use of exemplary practices. For example, on average, NGCP event attendees connected with nine new people and 70% of event attendees followed up with somebody they met there. Ninety-five percent of 2015 Annual Survey respondents indicted that using an exemplary practice led to a positive outcome in their program and 84% of respondents indicated exemplary practices helped them better serve girls This report also documents the impact of increased levels of collaboration and use of exemplary practices on girl-serving STEM programs, including increased efficiency and effectiveness. It was prepared by Education Development Center, evaluators of NGCP.