In the last decade, psychological science has undergone a period of self correction beginning with the joint publications of implausible but empirical evidence for ESP (Bem, 2011) and a report by Simmons and colleagues which showed that hidden flexibility in common analytical strategies in psychological science could elevate false positive rates to 60% (2011). A powerful tool which has emerged to combat questionable research practices is preregistration: the public recording of study rationale, hypotheses, methods, and analysis plan. Preregistration shifts the incentive structure to value “good science” over “good results” (Chambers, 2017). To date, common preregistration templates have focused on laboratory based experimental manipulations which cannot be easily applied to ongoing longitudinal developmental studies with hypotheses that were established before preregistration was commonly available. This project was initiated by a SRCD roundtable (March 22, 2019, Baltimore, USA), beginning with a discussion around the unique challenges and opportunities afforded by the extension of preregistration to ongoing longitudinal studies, which are critical designs for understanding human development. The panelists for this roundtable included: 1. Grace Binion, M.S., a doctoral student in Clinical Psychology at the University of Oregon. She is familiar with developmental longitudinal studies and analyses, and is experienced with open science practices as an ambassador for the Center for Open Science. 2. Andrew Dismukes, Ph.D., a postdoctoral fellow in Psychology at Penn State University. Dr. Dismukes has experience with longitudinal data from human development studies examining behavioral endocrinology and early life adversity. 3. Ece Demir-Lira, Ph.D., an assistant professor at the University of Iowa. As a graduate student at the University of Chicago, Dr. Demir-Lira was involved in the design of and collection of data from longitudinal studies of cognitive development in children. She is currently starting a research laboratory as a PI examining typical and atypical cognitive development. 4. Beatriz Luna, Ph.D., a professor in the Department of Psychiatry at the University of Pittsburgh. Dr. Luna is a senior PI who has substantial experience conducting large-scale longitudinal studies that answer key research questions about neurocognitive development in adolescents. Challenges to the extension of preregistration to mid-stage investigations include new grant proposals predicated upon existing study aims which cannot be modified, knowledge of prior measurement outcomes when considering future analyses which obscures traditional framing of exploratory vs confirmatory hypothesis framing, and many other issues about which it is crucial for developmental scientists to provide input. By the end of the session, we expected all participants (panelists included) to leave with a set of rough guidelines for mid-longitudinal study preregistration, and a specific plan to test this type of preregistration with their next research questions. The moderator (Michelle Byrne) and panelists will have a tangible outcome of revising the guidelines after the roundtable and using these to develop an OSF template (updates will be available on this page). We will advertise this OSF page/project and the process of developing the template not only during the roundtable itself but also on social media, listservs, and by asking colleagues to distribute it. By doing this, we hope to engage all developmental scientists, not only those that are able to attend the roundtable.