NIH/AHRQ/NIOSH jointly released Notice NOT-OD-19-083 on 2/15/19. This Notice updates and clarifies the NIH, AHRQ, and NIOSH policy for post-submission materials for applications submitted for due dates on or after May 25, 2019.
Post-submission materials are those submitted after submission of the grant application but prior to initial peer review. They are not intended to correct oversights or errors discovered after submission of the application, but rather allow applicants the opportunity to respond to unforeseen events.
The entire notice may be viewed here: https://grants.nih.gov/grants/guide/notice-files/NOT-OD-19-083.html.