 The National Children's Study Vanguard study assessed the feasibility, acceptability, and cost of using social media to support participant retention in longitudinal research. The study found that user participation varied over time, with the highest levels of activity occurring during the initial launch period. Overall, there was general enthusiasm among participants regarding the prospect of an online community. Several key considerations for integrating social media into longitudinal research were discussed, including privacy, security, and IRB clearance. Lessons learned from this experience included the importance of having a strong plan for data collection and storage, as well as the need for regular communication between researchers and participants. Finally, recommendations were made for future research seeking to use social media to improve retention in longitudinal studies. This article was authored by Amelia Bert Garcia, Kate Winsek, Leslie Cook Juvenile, and others.