Data Management Plans (DMPs) are often required for grant applications. But do strong DMPs lead to better data management and sharing practices? Several research projects in the Library and Information Science field have investigated data management planning and practice through analyzing DMP documents and conducting data-management-related interviews. However, research has not yet shown how DMPs ultimately affect data management and data sharing practices during grant-funded research. The proposed talk presents an overview of in-progress research focusing on two key questions: (1) Is there a difference between DMPs from awarded grant proposals and DMPs from declined proposals? and (2) Does writing a DMP affect researchers' data management and data sharing practice during a grant-funded project? The Data Management Plans as a Research Tool (DART) rubric was used to analyze 200 DMP documents from NSF grants—both awarded and declined. Follow-up interviews with DMP authors will provide a better understanding of how researchers use DMPs during their research process. The proposed talk will present hot-off-the-press results, with recommendations for practice that librarians can apply to help researchers write useful, actionable DMPs. By investigating how DMPs impact data management and sharing, this project can help academic libraries provide guidance that not only leads to stronger DMPs, but also to stronger data management and sharing practices.