The implementation date for the revised NSF Proposal and Award Policies and Procedures Guide (PAPPG) (NSF 19-1), which was scheduled to become effective on January 28, 2019, has been delayed. NSF will post a new implementation date on the NSF website as soon as practicable. In the interim, the current version of the PAPPG (NSF 18-1) applies. (https://www.nsf.gov/shutdown/grantees.jsp)